Can a 12VDC 500ma wall wart trickle charge a car battery?

[John]

Can a 12VDC 500ma wall wart trickle charge a car battery or must the voltage
to charge a car battery be greater than 12VDC (like 14 or 15 volts?).

Can a well regulated 12VDC still charge (over a long time) a car battery?

Or must it be over 13.5 volts to (eventually) accomplish full charging?

[Ralph Mowery]

In article <se6li2$is8$1...@gioia.aioe.org>, jo...@nospam.invalid says...

Unless they are regulated many of the 12 volt wall warts put out over 12
volts. It may not charge a car battery very much if it is one of the
unregulated ones ,but will maintain the charge.

A well regulated 12 volt supply will not charge a car battery as it 12.6
volts when charged.

It will take a higher voltage than 13 volts to charge a car battery.

Unless precautions are taken just hooking a power supply to a car
battery could damage the power supply especially if it is a regulated
one.

[amdx]

I did a short search hoping to find what current flows during trickle
charge. I was surprised to see 1 to 3 amps.

 This is supposed to match the self discharge rate.

Going by that, I doubt you could damage your battery with a 500ma wall wart.

There are different types of wall warts, regulated and unregulated. What
kind do you have?

If you have an unregulated type, measure the unloaded

voltage. say it is 15V and, guessing here, it is 12V when delivering
500ma. So it has an output impedance of 6 ohms.

If it delivered 100ma the voltage would be 14.4 Volts. 15V - (6Ω x
0.1A)= 14.4V

To be safe I would float it at 13.6 meaning add in series a resistor.
15V - 13.6V = 1.4V  then 1.4V / 0.1A = 14 Ω

you already have 6Ω internal so add 8Ω more.  Now you have 15V -(14Ω x
0.1V) = 13.6V  The max it will deliver at

13.6V is 100ma. this will rise to 14.86 at 10ma. But if the Self
discharge rate is higher (as suggested) your charge voltage will never
get that high.

 If you want to learn something do this, if you just want to keep the
battery charged go to Harbor Freight.

                                        Mikek

If you have an unregulated style, I'd experiment, if not spend $9 at
Harbor Freight and get one.

                                                         Mikek



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[Peter W.]

Those who go to Harbor Freight deserve exactly what they get.

Peter Wieck
Melrose Park, PA

[amdx]

 You mean a usable tool or device at a low price.

I have a dial indicator I bought 4 or 5 years ago, great price, does
what I need, and I'm not afraid

to use it to scribe a cut line, $9.99. I have a metal shear, it has done
every bend as expected. I use the

Bunker hill intruder alarm (93068, 69590, 62447, 61910) $10 or $11,
works well, I have even modified it

for special purposes. Neighbor bought a HF hammer drill, we both used it
during porch construction, I used one other time since.

It did the job, not something we need everyday, so why waste money.
Belt/disc sander, does everything I need. Wood clamps,

the work just fine.

 Things that didn't work a tiny air compressor, it fell apart, I got my
money back. I bought a HF drill press, it worked fine, had belt
adjustable speeds,

 what I didn't like was, it didn't have enough throw to drill the long
way through a 2" x 4". I did resell that and I'm in the market for a 
new drill press.

I may get a floor model.

If you are in construction and use a tool daily, sure by higher quality,
but for the home owner that may use a

tool 5 minutes twice a year, I'd rather have my money in the stock
market than in a quality tool I use twice a year.

[Rheilly Phoull]

What size battery needs 1 to 3amps for trickle charge ?
The average unit only needs around 300mA to maintain charge.

[Michael Trew]

It depends on what you need. I've gotten great deals at HF. Others,
not so much.

[Phil Allison]

John wrote:
=================

> Can a 12VDC 500ma wall wart trickle charge a car battery or must the voltage
> to charge a car battery be greater than 12VDC (like 14 or 15 volts?).

** Yes.

>
> Can a well regulated 12VDC still charge (over a long time) a car battery?
>

**No.

> Or must it be over 13.5 volts to (eventually) accomplish full charging?

** Yes.

........ Phil

[Phil Allison]

Ralph Mowery wrote:
=================

>
> Unless they are regulated many of the 12 volt wall warts put out over 12
> volts. It may not charge a car battery very much if it is one of the
> unregulated ones ,but will maintain the charge.
>

** Un-regulated ( transformer) AC to DC adaptors were banned in many places a few year ago.

The only kind allowed now are SMPS with self shut down when unloaded.

( AC to AC adaptors and special multi- voltage ones are excepted )




..... Phil

[Rob]

John <jo...@nospam.invalid> wrote:
> Can a 12VDC 500ma wall wart trickle charge a car battery or must the voltage
> to charge a car battery be greater than 12VDC (like 14 or 15 volts?).

It will depend on: is it an antique wall wart from the junk box (with
an iron core transformer, a rectifier and an electrolytic) or a modern
switchmode wall wart?

The latter will do absolutely nothing. The former may work, depending
on the parameters.

[amdx]

I thought the 1 to 3 amps was high myself.

I got that from here;

> https://batterymanguide.com/will-a-trickle-charger-charge-a-dead-battery/

> https://www.hemmings.com/stories/2013/09/06/tech-101-maintaining-and-charging-a-battery
The trickle charger produces a constant small amp charge, usually 2 amps
or less, that keeps the battery fully charged while at rest.

I had one other 1 to 3 amp reference, but can't find it now. Anyway, I
thought it would be less current.

Here's a site that may be helpful to the OP.

[Peter W.]

> You mean a usable tool or device at a low price.

I don't, no.

https://www.amazon.com/Channellock-349-Premium-Wiremaster-Linesman/dp/B00004SBD5

https://www.harborfreight.com/9-in-linesman-pliers-63820.html

The former keeps a small town in western Pennsylvania vibrant with hundreds of well-paying jobs. The steel is sourced from the US and the profits remain in the US.
The latter keeps a sweatshop in China working with hundreds of poorly paying jobs. The steel is sourced from China, and the profits remain in China.
Yes, there is a cost difference. The first time one cuts a 'live wire' with either tool, the result of that cost difference will be instantly manifest. Bit of advice - do not try that with the HF option.

Tools have a purpose, true. And often the need drives the choices, true. But:

One choice provides my neighbor with a job so that he/she may support a family and maintain a life. The other does not. If I am not conscious of the difference between the two options, and should it come to pass that my neighbor's choices and options put me out of a job, then I have no grounds for complaints. If I am conscious of the differences, then my neighbor and I have an obligation to support each other to our mutual benefit.

Sometimes, there is no choice, and sometimes one is forced to purchase from China, or similar Pacific Rim sources. LCD screens (invented in Pittsburgh, PA, USA) come to mind. And many similar items. But where there is a choice, at the very least, make that choice with full awareness of the consequences.

[amdx]

While I do agree on the buy American sentiment, it's not all that easy
to find an American made tool. And as you see, there is a 3x premium to
get that.

I was against import fees, but if we could use them to slow down China,
I'm all for them, but I'm afraid we are 20 years late to that party.

[Jeff Liebermann]

Lots of things wrong here:
1. Common flooded car batteries will not charge using a small trickle
charge. You can use a trickle charge to maintain the charge level of
an already charged battery, but you cannot take (for example) a half
charged battery and bring it to full charge with a trickle charger.
2. The charge voltage on a common flooded car battery is about 14.5V
and varies with temperature, battery condition, battery age, etc.
<https://batteryuniversity.com/article/bu-403-charging-lead-acid>
3. A linear 12VDC/500ma might have a no-load output voltage of
perhaps 15V, but under full 500ma load, will probably drop below 12V
making battery charging problematic. A switching type power supply
has a built in voltage regulator and will produce 12.0V at any load
below 500ma making battery charging impossible.
4. A power supply that produces 13.5V will not charge a battery with
a no load voltage of 13.6V (fully charged). You need a voltage
difference to produce charging current.
5. Today's overpriced car batteries cost about $100. Would you
really risk trashing a $100 battery because you don't want to use a
proper battery charger? I wouldn't. Unfortunately, a charger with a
fancy label is not a guarantee of quality. All these chargers were
defective in some manner. They also killed two rather expensive
stationary batteries at a radio site:
<http://www.learnbydestroying.com/jeffl/pics/drivel/dead-battery-chargers.jpg>
Spend some time and do some reading on chargers.
6. If you're looking for a "battery maintainer", I suggest you check
what is being offered for boating. They tend to be better built, be
better designed, and unfortunately cost most, than the common
automotive and home user variety. RV and recreational maintainers are
in between.
<https://www.westmarine.com/mounted-battery-chargers>
<https://www.westmarine.com/portable-chargers>
If you don't like the prices, remind yourself what a new battery might
cost if your charger tries to kill it.

Good luck.


--
Jeff Liebermann je...@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

[Peter W.]

> I was against import fees, but if we could use them to slow down China,
> I'm all for them, but I'm afraid we are 20 years late to that party.

Import fees are also known as Tariffs - and you see how well that worked out.

> it's not all that easy to find an American made tool.

Agreed. But the internet is your friend.

https://www.dewalt.com/products/power-tools/products-made-in-the-usa

https://www.protoolreviews.com/what-tools-are-made-in-the-usa/

https://www.toolbarn.com/usa-made-tools/

Are three sources of many.

I guess my gripe is that that as a nation, we are racing for the bottom with our education, our environment, our civil discourse and many other aspects of being a first-world nation. We are now in a race to be the best-armed third-world nation on the planet....

You have seen this rant before:

Keep in mind that the Average American:

Does not have a college education, including an Associate Degree (60%).
Does not have a passport (63%).
Speaks one language – badly (74%).
Has never traveled voluntarily more than 200 miles from his/her birthplace (57%).
Has never visited a foreign country, not even Mexico or Canada (71%).
Cannot name the Speaker of the House, even today (82%)
Cannot name the three branches of government (64%)
Cannot read at a college level (83%)
Cannot read for content (54%). This person cannot follow written-only directions.
60% of American Households do not buy any book in a year.
Does not believe in Evolution (42% creationism, 32% evolution, 26% no opinion).

Worst of all: The Average American does not vote. 66.2% of registered voters voted in 2020, a record! However, only 66.7% of eligible voters were actually registered. That means that only 44.2% of eligible voters actually voted.

Pretty abysmal stats.

[Ralph Mowery]

In article <uo8ggg5e5fqegsktt...@4ax.com>,
je...@cruzio.com says...

> 5. Today's overpriced car batteries cost about $100. Would you
> really risk trashing a $100 battery because you don't want to use a
> proper battery charger? I wouldn't. Unfortunately, a charger with a
> fancy label is not a guarantee of quality. All these chargers were
> defective in some manner. They also killed two rather expensive
> stationary batteries at a radio site:
> <http://www.learnbydestroying.com/jeffl/pics/drivel/dead-battery-chargers.jpg>
> Spend some time and do some reading on chargers.
> 6. If you're looking for a "battery maintainer", I suggest you check
> what is being offered for boating. They tend to be better built, be
> better designed, and unfortunately cost most, than the common
> automotive and home user variety. RV and recreational maintainers are
> in between.
> <https://www.westmarine.com/mounted-battery-chargers>
> <https://www.westmarine.com/portable-chargers>
> If you don't like the prices, remind yourself what a new battery might
> cost if your charger tries to kill it.
>
>
>

Yes, even high dollar charges do not guarenee they will not fry a
battery.

At work we had some stand by pumps for fire protection. The batteries
to start the Diesel engines were under constant charge by some very high
dollar chargers. We would only get about 3 months of service out of the
batteries. The engines (we had 2) were started for about an hour every
week as a test. I don't think they were ever used because of a fire.

We even had a battery charger company service man to come by about 3 or
4 times because the chargers were cooking the batteries.
The batteries were the old lead acid type and were checked for water and
specific gravity every week.

If not for the voltage of them, we probably would have been better off
with the $ 10 Harbor Freight Battery maintainer.

I bought one of those to put on my 3.5 kw portable generator and hook it
up for a day or so every month. The battery is no where near the size
of a car battery.

Been working ok for the last 2 years.

For my lawn tractor that is not used from about November to March I have
one of the solar cell battery maintainers as there is no power in the
shed for it. Seems to keep the battery charged.

[Chris Jones]

On 02/08/2021 12:57, Phil Allison wrote:
> Ralph Mowery wrote:
> =================
> >
>> Unless they are regulated many of the 12 volt wall warts put out over 12
>> volts. It may not charge a car battery very much if it is one of the
>> unregulated ones ,but will maintain the charge.
>>
>
> ** Un-regulated ( transformer) AC to DC adaptors were banned in many places a few year ago.

Theoretically they are not banned, but to be allowed, they would have to
have very low standby consumption which might make them uneconomical to
manufacture.

I have seen a few sold recently in Australia, but have not investigated
whether they really have very low standby consumption or are just
non-compliant.

[amdx]

On 8/2/2021 12:44 PM, Peter W. wrote:
>> I was against import fees, but if we could use them to slow down China,
>> I'm all for them, but I'm afraid we are 20 years late to that party.
> Import fees are also known as Tariffs - and you see how well that worked out.

Yes, tarriff's are what I meant, we should never had made China as well
off as they are, over the long term I think we have lost that war.

It is a funny thing that we all have a higher standard of living because
of Chinese imports, but it can not last over the long term.

>> it's not all that easy to find an American made tool.
> Agreed. But the internet is your friend.
>
> https://www.dewalt.com/products/power-tools/products-made-in-the-usa
>
> https://www.protoolreviews.com/what-tools-are-made-in-the-usa/
>
> https://www.toolbarn.com/usa-made-tools/
>
> Are three sources of many.
>
> I guess my gripe is that that as a nation, we are racing for the bottom with our education, our environment, our civil discourse and many other aspects of being a first-world nation. We are now in a race to be the best-armed third-world nation on the planet....
>
> You have seen this rant before:
>
> Keep in mind that the Average American:
>
> Does not have a college education, including an Associate Degree (60%).
> Does not have a passport (63%).
> Speaks one language – badly (74%).
> Has never traveled voluntarily more than 200 miles from his/her birthplace (57%).
> Has never visited a foreign country, not even Mexico or Canada (71%).
> Cannot name the Speaker of the House, even today (82%)
> Cannot name the three branches of government (64%)
> Cannot read at a college level (83%)
> Cannot read for content (54%). This person cannot follow written-only directions.
> 60% of American Households do not buy any book in a year.

> Does not believe in Evolution (42% creationism, 32% evolution, 26% no opinion).

   OK, that one just floors me! That must be brainwashing that won't
succumb to knowledge.

>
> Worst of all: The Average American does not vote. 66.2% of registered voters voted in 2020, a record! However, only 66.7% of eligible voters were actually registered. That means that only 44.2% of eligible voters actually voted.
>
> Pretty abysmal stats.
>
> Peter Wieck
> Melrose Park, PA

[Clifford Heath]

It's a no-brainer to pay 3x premium for a product that will be easier to
use, do better work, and last 3x longer.

Sadly however that is not the case. The multiplier is often 10x, and the
product is not better than (say) a Japanese product at only 3x.

America and Australia both have "buy local-product" campaigns. What we
need instead is a "sell local-product" campaign, to push manufacturers
to make globally-competitive products at a good price-point. When
Australia finally started making cars that filled a niche and were
competitive on price and quality - the niche started to evaporate,
government support was exhausted, and the manufacturers decided to move
manufacturing elsewhere. Same goes for electronics, whitegoods. and many
other products. Managers in multi-national owners buy into the mantra
that all manufacture should be offshored to Asia, so they do that, and
wonder why their brand reputation collapses over the next few years.
It's crazy.

Both countries (and probably many others) need to aggressively
*on-shore* manufacturing, if only to reduce sovereign risk. The focus
must be to produce products that are globally competitive on quality and
price - i.e. manufactures must be assisted to address a global market.

The "buy A" campaigns are like Ford executives calling an all-staff
meeting and telling everyone they should buy a Ford, to keep the company
afloat so they can continue to pay salaries... while continuing to make
cars that no-one else wants to buy. It's crazy and inadequate thinking.
Meet the competitive global market or change business.

... and tax the crap out of imported products that are underpriced only
due to the value of labour, life and the environment being undervalued
in Asia. Not protectionism, just fair competition.

CH.

[Clifford Heath]

On 3/8/21 3:21 am, Jeff Liebermann wrote:
> Lots of things wrong here:
> 1. Common flooded car batteries will not charge using a small trickle
> charge. You can use a trickle charge to maintain the charge level of
> an already charged battery, but you cannot take (for example) a half
> charged battery and bring it to full charge with a trickle charger.

Why is that Jeff? Surely any charger that exceeds the self-discharge
current will eventually charge the battery?

[Phil Allison]

** Yep - I know all about the MEPS regulations.
My colleague Rod Elliott attended one of the " stake holder" meetings in Sydney.

As with the case of incandescent light bulbs, the rule was made ( exquisitely) to exclude them and transformer external adapters. Initially it affected all such, including AC- AC types - but was amended under protest that there was NO alternative.

Now, it is possible to make a low standby, AC -DC adapter with an iron transformer.

1. Double the usual primary turns to lower I mag.
2. Use a toroidal core.

The first will mean the VA rating is halved and regulation is poor.
Using larger core does not help - cot is involves doubling Imag.

The second is out of the question since it is not possible to make a regular toroidal that complies with the safety standards.
External adapters are "prescribed items " that must pass lab testing for user safety under all overload, spike voltage and overheating scenarios. The extremely close proximity of primary and secondary windings does not permit this.

The JOKE is that SMPS adapters are inherently unsafe - though technically complying with the existing rules.
Liquid ingress, the failure ( leaking) of an electro cap or the often fake Y-cap fails and bridges isolation.

MEPS enthusiasts were not interested in facts, user safety was not their problem.

Cos they were saving the planet.....

..... Phil

[Jeff Liebermann]

On Mon, 2 Aug 2021 10:44:14 -0700 (PDT), "Peter W."
<peterw...@gmail.com> wrote:

>> it's not all that easy to find an American made tool.

>Agreed. But the internet is your friend.
>https://www.dewalt.com/products/power-tools/products-made-in-the-usa
>https://www.protoolreviews.com/what-tools-are-made-in-the-usa/
>https://www.toolbarn.com/usa-made-tools/
>Are three sources of many.

Careful. "Made in the USA" is actually "Select Products Made in the
USA with Global Materials". That's exactly what the DeWalt page
shows. It's much the same with most other large tool vendors. The
standard joke is that the tools are made in China or elsewhere, but
the stick on labels are attached in the USA. Some of the former large
warehouses have been converted into "factories" where the "production
line" adds labels, assembles kits, adds legal documents, and stuffs
them in cardboard boxes. A major clue is that these "factories" have
very few employees compared to the square footage.

"New Craftsman Texas Factory Updates! (#ChromingSoon #MadeInUSA*)"
<https://www.youtube.com/watch?v=Uc2wM6EV2K8> (13:23)

Note: DeWalt, Craftsman, and many others are owned by Stanley Black &
Decker. More:
<https://toolguyd.com/tool-brands-corporate-affiliations/>
<https://www.protoolreviews.com/news/power-tool-manufacturers-who-owns-them/43632/>
<https://pressurewashr.com/tool-industry-behemoths/>

The video lists two companies that really do make everything in the
USA.
<https://www.tekton.com/about-us>
<http://www.wrighttool.com/frequently-asked-question.html>
S-K Tool is mostly made in USA, but was recently sold to Chinese
investors:
<https://sktools.com/made-in-usa.html>
<https://toolguyd.com/greatstar-aquires-sk-hand-tool-from-ideal-industries/>

"What Tools Are Made in the USA?"
<https://www.protoolreviews.com/what-tools-are-made-in-the-usa/>
Note that most of the companies listed include the "from global
materials" qualifier in the article.

So, are there any real "Made in USA" tool companies? Hard to say was
long as the FTC tolerates the "Select Products Made in the USA with
Global Materials" baloney and deceptive advertising.

[Rob]

Usually such regulations cover the use of an adapter as part of a system,
e.g. a phone charger or a newly designed device with 12V power wall wart,
but it does not preclude the sale of the separate component e.g. to use
it as a service part for older equipment, or the sale of old stock.

So it is likely still legal to sell old style wall warts which could be
used in this application, you just won't find them packaged with your
new toys anymore.

[Jeff Liebermann]

On Tue, 3 Aug 2021 11:46:55 +1000, Clifford Heath <no....@please.net>
wrote:

I don't know and I've never seen it explained in print. Someone told
me that many years ago and my experience seems to verify the claim.
When I've tried to charge large lead-acid car batteries which have
been substantially drained (about 50%), with a small "battery
maintainer" or "battery tender", it has usually failed to charge. Not
always, just usually. With small lead-acid batteries, it will charge.
Unfortunately, I haven't made any proper measurements. Just the usual
RV, boat, radio site, home backup, generator starter, type operation.
There are a few clues here and there. For example:
<https://batteryglobe.com/battery-tender-1-25amp-vs-4amp-vs-5amp/>
Charging Capability
All three battery tenders can charge smaller vehicle
batteries such as motorcycle and ATV batteries.
However, only the 4A and 5A battery tenders can charge
car and SUV systems, due to their higher power output;
the 1.25A battery tender can only maintain car and SUV
battery systems.
(...)
Unfortunately, the Battery Tender 1.25A cannot charge
anything larger than an ATV battery. You can use it
to maintain the car battery, but do not expect it to
charge it.

Fasten your seat belt before checking the price of a decent battery
maintainer:
<https://www.amazon.com/gp/product/B000CITK8S/?th=1>
I had something similar on my emergency generator.
<http://www.learnbydestroying.com/jeffl/Generators/DuroMax%20XP4400e/DuroMax%20XP4400E.jpg>
Note the larger yard tractor battery instead of the tiny stock
generator starting battery. The generator had a built in charger
module that blew up. So, I keep the battery charged with a battery
maintainer (not shown). I'll run the battery down to about 60% and
see what happens (if I can find where I put the battery maintainer).

It is not beneath my dignity to plug a large battery charger into the
generator, and use it to charge the generator starting battery. I'll
eventually be converting the generator starting battery to LiFePO4
plus supercaps. One advantage is that the battery has a very low
self-discharge rate. Instead of a battery maintainer, I only need to
fully charge the battery and disconnect the charger. The charge holds
at about 80-85% for many months.

[Chris Jones]

No, one of the ones I purchased fairly recently was packaged with an
appliance sold at a physical shop in Australia and has seemingly genuine
Australian compliance markings on it - it is not some banggood grey
import. I still suspect it does not meet MEPS rules (as it was not an
application where it would make commercial sense to make a special
efficient transformer instead of using a SMPS) but so far I haven't
bothered to test it.

[Clifford Heath]

On 3/8/21 5:48 pm, Jeff Liebermann wrote:
> On Tue, 3 Aug 2021 11:46:55 +1000, Clifford Heath <no....@please.net> wrote:
>> On 3/8/21 3:21 am, Jeff Liebermann wrote:
>>> 1. Common flooded car batteries will not charge using a small trickle
>>> charge. You can use a trickle charge to maintain the charge level of
>>> an already charged battery, but you cannot take (for example) a half
>>> charged battery and bring it to full charge with a trickle charger.
>
>> Why is that Jeff? Surely any charger that exceeds the self-discharge
>> current will eventually charge the battery?
>
> I don't know and I've never seen it explained in print. Someone told
> me that many years ago and my experience seems to verify the claim.
> When I've tried to charge large lead-acid car batteries which have
> been substantially drained (about 50%), with a small "battery
> maintainer" or "battery tender", it has usually failed to charge. Not
> always, just usually. With small lead-acid batteries, it will charge.

It could be something as simple as self-discharge being much larger when
a battery has been "substantially drained"...?

> I'll eventually be converting the generator starting battery to LiFePO4
> plus supercaps. One advantage is that the battery has a very low
> self-discharge rate. Instead of a battery maintainer, I only need to
> fully charge the battery and disconnect the charger. The charge holds
> at about 80-85% for many months.

Yes, I use LiFePO4 also. Self-discharge is 1-2% per annum, and the
columetric efficiency is very high also (you get back almost all the
charge you put in). Great batteries.

[Rob]

Ok I am not familiar with the situation in Australia, but here in Europe
most equipment is delivered with SMPS wall warts these days, they probably
are cheaper as well. And I have done some testing with a power meter
(HOPI) and most of them consume no measurable power when unloaded. That
was the objective of the regulation, so it achieved that goal well.

[Chris Jones]

Yes here also, nearly every wall wart is a SMPS, partly due to
regulations in the EU (they likely come from the same factory just with
different shaped pins on them), but partly because of similar local laws
that require low standby consumption. That's why I was surprised to
receive one of the heavier sort with a new appliance.

[Jeff Liebermann]

On Tue, 3 Aug 2021 22:34:01 +1000, Clifford Heath <no....@please.net>

wrote:

>On 3/8/21 5:48 pm, Jeff Liebermann wrote:
>> On Tue, 3 Aug 2021 11:46:55 +1000, Clifford Heath <no....@please.net> wrote:
>>> On 3/8/21 3:21 am, Jeff Liebermann wrote:
>>>> 1. Common flooded car batteries will not charge using a small trickle
>>>> charge. You can use a trickle charge to maintain the charge level of
>>>> an already charged battery, but you cannot take (for example) a half
>>>> charged battery and bring it to full charge with a trickle charger.
>>
>>> Why is that Jeff? Surely any charger that exceeds the self-discharge
>>> current will eventually charge the battery?
>>
>> I don't know and I've never seen it explained in print. Someone told
>> me that many years ago and my experience seems to verify the claim.
>> When I've tried to charge large lead-acid car batteries which have
>> been substantially drained (about 50%), with a small "battery
>> maintainer" or "battery tender", it has usually failed to charge. Not
>> always, just usually. With small lead-acid batteries, it will charge.

>It could be something as simple as self-discharge being much larger when
>a battery has been "substantially drained"...?

Much as I like to speculate about things I'm not quite sure, I'll take
a chance and add a few guesses:

1. Extremely crude battery maintainers are common. Just fixed
maximum voltage source and a series resistor. As the battery voltage
approaches the voltage source voltage, charging slows down and
eventually stop. Pick the wrong voltage or series resistor and it
might never get to full charge. Variations in line voltage can also
create problems with unregulated battery maintainers.

2. Flooded cell batteries are quite sensitive to temperature. The
better chargers have circuitry to compensate for temperature effects.
The really good one's have an external thermistor sensor that attaches
to the battery. The best have individual voltage and temperature
sensors for each cell. Crude temperature compensation assumes that
the battery and charger are at the same temperature. That's often not
the case, such as the battery sitting on a cold concrete floor, while
the charger is in a relay rack full of very hot radios. I've seen
this all too often at radio sites.

3. Self-discharge in flooded cells batteries increases with
temperature. See Fig 6:
<https://batteryuniversity.com/article/bu-802b-what-does-elevated-self-discharge-do>

4. Flooded batteries that have lost water and have exposed the tops
of the plates to air act weird. One effect is an increase in self
discharge rate, possibly caused by internal self-heating from
self-discharge. For example, losing 50% capacity from a flooded
lead-acid battery in 6 months would be half of the manufacturers rated
capacity of perhaps 70 amp-hrs or 840 watt-hrs.
420 watt-hrs / 180 days / 24 hrs/day = 0.1 watt/day
That doesn't seem like much, but that's under fairly ideal conditions,
with a new battery, no sulfation, etc. The self-heating will be
slight, but if it causes additional self-discharge, the effect is
positive feedback and might result in enough self-discharge to
interfering with low level charging.

>Yes, I use LiFePO4 also. Self-discharge is 1-2% per annum, and the
>columetric efficiency is very high also (you get back almost all the
>charge you put in). Great batteries.

Yep, they're amazing with the added bonus of having a 3.3V nominal
voltage which produces almost the same voltage as a common automobile
battery (4S = 13.2V). They're also good for a much larger number of
charge cycles than ordinary LiIon cells.
LiFePO4 = 2000 cycles
LiCoO2 = 400 cycles
Lots of other advantages (such as not catching fire or bulging), but
there are also problems. Plagiarized from:
<https://www.solacity.com/how-to-keep-lifepo4-lithium-ion-batteries-happy/>
- Keep the battery temperature under 45 Centigrade (under 30C if
possible) - This is by far the most important!!
- Keep charge and discharge currents under 0.5C (0.2C preferred)
- Keep battery temperature above 0 Centigrade when discharging if
possible - This, and everything below, is nowhere near as important as
the first two.
- Do not cycle below 10% - 15% SOC unless you really need to.
- Do not float the battery at 100% SOC if possible.
- Do not charge to 100% SOC if you do not need it.

My plan for an emergency generator starting battery is quite
different. I plan to use a fairly small battery pack. It can be
almost anything. Initially, I'll start with a 12V 7AH AGM battery.
Across the battery are 6 super caps:
<https://www.ebay.com/itm/193649838256> $21
I'm not sure of the size needed yet. The super caps provide the high
motor start current needed. The AGM battery keeps the caps charged. A
small float charger keeps the AGM battery charged between starts.

[Michael Terrell]

On Tuesday, August 3, 2021 at 2:34:59 AM UTC-4, Jeff Liebermann wrote:
> On Mon, 2 Aug 2021 10:44:14 -0700 (PDT), "Peter W."
> <peterw...@gmail.com> wrote:
>
> >> it's not all that easy to find an American made tool.
>
> >Agreed. But the internet is your friend.
> >https://www.dewalt.com/products/power-tools/products-made-in-the-usa
> >https://www.protoolreviews.com/what-tools-are-made-in-the-usa/
> >https://www.toolbarn.com/usa-made-tools/
> >Are three sources of many.
> Careful. "Made in the USA" is actually "Select Products Made in the
> USA with Global Materials". That's exactly what the DeWalt page
> shows. It's much the same with most other large tool vendors. The
> standard joke is that the tools are made in China or elsewhere, but
> the stick on labels are attached in the USA. Some of the former large
> warehouses have been converted into "factories" where the "production
> line" adds labels, assembles kits, adds legal documents, and stuffs
> them in cardboard boxes. A major clue is that these "factories" have
> very few employees compared to the square footage.

Do you remember back in the '60s when consumer electronics were often labeled with the percentage of foreign made parts? I remember cheap TVs with Japanese built TV tuners that would melt or crumble because they used polystyrene instead of fiber or ceramic insulators. Once one needed cleaning, they were often scraped because no replacements were available.

Even if something is assembled in the USA, it often has no US made components since the US companies were sold to overseas interests who closed the US facilities. Sprague was one of the early losses, in the '90s. A place that I worked sold off the remaining production equipment. It is now part of Vishay, along with a lot of other, former US suppliers and nothing is made on shore.
Some friends of mine manufacture high quality canopies for art shows. Every company that made the required heavy vinyl they used has moved off shore. Instead of being able to call a US OEM for a couple rolls a month, they have to buy the rolls by the pallet load, and wait months instead of days for delivery. This of course got them bounced off all the 'Made in the USA lists even though they make every part from raw materials.

[Ralph Phillips]

Back in the late 70's I worked at a commercial cooking product company.

We (the company) decided to design their own fryer timer, instead of
buying them.

So, as part of the "Made in the USA" initiative, we searched and sorted
and found optoisolators (4N35s to be precise) that were made and sold by
GE, being an American company. The others that would do what we needed
were made by Toshiba and Sony.

So we get our 4N35s in. All stamped "Made in Yugoslavia". In 1978.

RwP

[Michael Terrell]

On Monday, September 6, 2021 at 12:09:53 PM UTC-4, Ralph Phillips wrote: >
> Back in the late 70's I worked at a commercial cooking product company.
>
> We (the company) decided to design their own fryer timer, instead of
> buying them.
>
> So, as part of the "Made in the USA" initiative, we searched and sorted
> and found optoisolators (4N35s to be precise) that were made and sold by
> GE, being an American company. The others that would do what we needed
> were made by Toshiba and Sony.
>
> So we get our 4N35s in. All stamped "Made in Yugoslavia". In 1978.

The first TTL ICs that I purchased for a project in 1971 They were branded Texas Instruments and from Pioneer Electronics, a wholesale industrial suppler in SW Ohio. $7 each for 7447 display drivers, and they were made in Malaysia.

[Jeff Liebermann]

On Sun, 5 Sep 2021 23:17:47 -0700 (PDT), Michael Terrell
<terrell....@gmail.com> wrote:

>Do you remember back in the '60s when consumer electronics were often labeled with the percentage of foreign made parts?

Actually, no. During the 60's, I was doing warranty repair service on
imported hi-fi and audio hardware, so I wouldn't have seen any such
labels. If there were such labels, they would probably say something
like "100% foreign components".

>I remember cheap TVs with Japanese built TV tuners that would melt or crumble because they used polystyrene instead of fiber or ceramic insulators. Once one needed cleaning, they were often scraped because no replacements were available.

That's still the situation, at least in the personal computah sector.
Components are selected to self destruct just after the warranty
expires. It's easy to build a "warranty timer" using electrolytic
capacitors:
<https://www.illinoiscapacitor.com/tech-center/life-calculators.aspx>
<https://eepower.com/tools/electrolytic-capacitor-life-calculator/>
<https://www.nichicon.co.jp/english/products/lifetime/>
<https://www.nichicon.co.jp/english/products/lifetime/ripple.html>
It was quite common for me to see a monitor or PCB with a huge
percentage of the electrolytics that tested bad on an ESR tester, or
which have the tops blown out caused by overheating from excessive
ripple current.

I'll leave out my customary "Right to Repair" rant.

>Even if something is assembled in the USA, it often has no US made components since the US companies were sold to overseas interests who closed the US facilities. Sprague was one of the early losses, in the '90s. A place that I worked sold off the remaining production equipment. It is now part of Vishay, along with a lot of other, former US suppliers and nothing is made on shore.

Yep. That trend continues. Try finding a "white goods" appliance
made in the USA at any price. They actually do exist, but only for
higher cost industrial purposes. The current transition from
Craftsman tools from mostly US made to foreign ownership and
manufacture is accompanied by a general lack of quality workmanship
and finishing. The sticker doesn't say "Made in USA". It says "Made
in USA from global materials" which is effectively an oxymoron and
means nothing. Today, there are very few hand tool manufacturers that
actually make their tools in the USA.

Hair splitting:
<https://ell.stackexchange.com/questions/52129/made-in-usa-vs-made-in-the-usa>

When I worked for a US marine radio manufacturer in the 1970's, I once
priced out the US 1K quantity component cost for a competing radio
from Japan. No labor, test, QA, manuals, shipping boxes, overhead,
etc. Just the components and major mechanical parts. The total parts
cost was about 7 times the wholesale selling price of the Made in
Japan radios. If I added my guess for the items I omitted, double
that.

>Some friends of mine manufacture high quality canopies for art shows. Every company that made the required heavy vinyl they used has moved off shore. Instead of being able to call a US OEM for a couple rolls a month, they have to buy the rolls by the pallet load, and wait months instead of days for delivery. This of course got them bounced off all the 'Made in the USA lists even though they make every part from raw materials.

My father used own a factory that made lingerie. The same thing
happend to his suppliers of nylon net material.

It's a small step from importing just the components and materials
from an offshore vendor, to doing everything offshore. Today, US
consumers are benefiting from low cost overseas manufacturing costs.
As the standard of living in these formerly 3rd world countries
increases, the US standard of living will decrease proportionally
until everything evens out. There's a fair chance that the US might
end up a 3rd world country or as the worlds biggest customer.

In case you haven't noticed, most of the leading manufacturers of high
tech consumer electronics are doing everything possible to reduce the
useful life of their products. Much of what I see is barely adequate
for the intended purpose, unrepairable, but cheap enough for anyone on
stimulus payments or extended unemployment to afford.

Very fitting topic for Labor Day.

[Phil Allison]

Ralph Phillips wrote:
==================

>
> So, as part of the "Made in the USA" initiative, we searched and sorted
> and found optoisolators (4N35s to be precise) that were made and sold by
> GE, being an American company. The others that would do what we needed
> were made by Toshiba and Sony.
>
> So we get our 4N35s in. All stamped "Made in Yugoslavia". In 1978.
>

** If you check it out - the main motive for shifting semiconductor fabrication off to impoverished places like that was to avoid health and safety regulations in the USA. They were too expensive to comply with.

Life was cheap in Yugoslavia.

..... Phil

[Three Jeeps]

On Monday, August 2, 2021 at 1:21:24 PM UTC-4, Jeff Liebermann wrote:
> On Sun, 1 Aug 2021 19:27:45 +0200, John <jo...@nospam.invalid> wrote:
>
> >Can a 12VDC 500ma wall wart trickle charge a car battery or must the voltage
> >to charge a car battery be greater than 12VDC (like 14 or 15 volts?).
> >
> >Can a well regulated 12VDC still charge (over a long time) a car battery?
> >
> >Or must it be over 13.5 volts to (eventually) accomplish full charging?
> Lots of things wrong here:

> snip.......

> 5. Today's overpriced car batteries cost about $100. Would you
> really risk trashing a $100 battery because you don't want to use a
> proper battery charger? I wouldn't. Unfortunately, a charger with a
> fancy label is not a guarantee of quality. All these chargers were
> defective in some manner. They also killed two rather expensive
> stationary batteries at a radio site:
> <http://www.learnbydestroying.com/jeffl/pics/drivel/dead-battery-chargers.jpg>
> Spend some time and do some reading on chargers.

> snip

> Good luck.
>
>
> --
> Jeff Liebermann je...@cruzio.com
> PO Box 272 http://www.LearnByDestroying.com
> Ben Lomond CA 95005-0272
> Skype: JeffLiebermann AE6KS 831-336-2558

Automobile batteries must cost less in LHS USA than in RHS. I recently got a car battery for my 2004 Saab 9-5, at $150 from Walmart ( made by Johnson Controls). The AGM one for a 2016 Volvo was $200. One for the 2004 Grand Cherokee was $160. All were purchases within the last six months. I keep an eye out for sales and these prices are not regular retail. Three to four years ago each battery would have been about $30-$40 USD less (not sure about the AGM as these seem to be hyped as the new&better battery tech). Guess it is another symptom of the blame it on covid money grab.
Even more reason not to kill a battery with an inappropriate charger.
J

[bilou]

Le 01/08/2021 à 19:36, Ralph Mowery a écrit :
> In article <se6li2$is8$1...@gioia.aioe.org>, jo...@nospam.invalid says...
>>

>> Can a 12VDC 500ma wall wart trickle charge a car battery or must the voltage
>> to charge a car battery be greater than 12VDC (like 14 or 15 volts?).
>>
>> Can a well regulated 12VDC still charge (over a long time) a car battery?
>>
>> Or must it be over 13.5 volts to (eventually) accomplish full charging?
>>
>>
>

> Unless they are regulated many of the 12 volt wall warts put out over 12
> volts. It may not charge a car battery very much if it is one of the
> unregulated ones ,but will maintain the charge.
>

> A well regulated 12 volt supply will not charge a car battery as it 12.6
> volts when charged.
>
> It will take a higher voltage than 13 volts to charge a car battery.
>
> Unless precautions are taken just hooking a power supply to a car
> battery could damage the power supply especially if it is a regulated
> one.
>
>

Using something not designed for to charge batteries is a bad idea.
Leaving it connected his way for weeks is worse
The main reason is that there is no protection against the load feeding
back power and eventually starting a fire.
I think using a timer on a normal charger to limit it to a few
minutes/hours per week is much better.