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Trying to get the most out of a charger.
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Micky
Nov 13, 2015, 12:49:07 AM11/13/15
to
I need a DC power supply, bigger than what I've got. Any reason why I
can't connect two automobile battery chargers in parallel to suply the
same vehicle?
Let's say one puts out 13.8 volts and the other 14.2. Is the first
one really going to be a load on the second?
What happens if they are both connected to a discharged lead acid
battery that's now putting out 4 or 8 volts**? Won't that lower the
voltage of the 14.2 charger to where it's not backcharging the 13.8
charger? And won't the battery charge at rate of the sum of the two
chargers, 2 (or 10) amps and 10 amps?
**Or if they are both connected to motor scooter whose starter motor
is engaged.
A separate question: The charger I'm using now has 2 amp and 10 amp
settings. It was on 2 amps, to charge a sealed burglar alarm style
lead acid gel battery, used in place of a motorcycle battery in a
motorscooter I'm working on. When I pressed the starter button to
electrically crank the engine, the ammeter on the charger went
immediately all the way to the right, 10 amps or more. But it was
not enough to crank the engine. It made an effort, a little noise,
and stopped immediately.
Given the way chargers are usually wire, will setting the charger on
10 amps provide more starting power than setting it on 2 amps? I
would have assumed the answer was yes, but the ammeter went to 10 amps
even in the 2 amp setting.
And before anyone brings it up, I've been testing the kick starter
too, and the ignition and fuel systems. I'm making mulitples tests,
in order to test all the systems. Before I recommend spending money
on a battery and a couple other parts.
can't connect two automobile battery chargers in parallel to suply the
same vehicle?
Let's say one puts out 13.8 volts and the other 14.2. Is the first
one really going to be a load on the second?
What happens if they are both connected to a discharged lead acid
battery that's now putting out 4 or 8 volts**? Won't that lower the
voltage of the 14.2 charger to where it's not backcharging the 13.8
charger? And won't the battery charge at rate of the sum of the two
chargers, 2 (or 10) amps and 10 amps?
**Or if they are both connected to motor scooter whose starter motor
is engaged.
A separate question: The charger I'm using now has 2 amp and 10 amp
settings. It was on 2 amps, to charge a sealed burglar alarm style
lead acid gel battery, used in place of a motorcycle battery in a
motorscooter I'm working on. When I pressed the starter button to
electrically crank the engine, the ammeter on the charger went
immediately all the way to the right, 10 amps or more. But it was
not enough to crank the engine. It made an effort, a little noise,
and stopped immediately.
Given the way chargers are usually wire, will setting the charger on
10 amps provide more starting power than setting it on 2 amps? I
would have assumed the answer was yes, but the ammeter went to 10 amps
even in the 2 amp setting.
And before anyone brings it up, I've been testing the kick starter
too, and the ignition and fuel systems. I'm making mulitples tests,
in order to test all the systems. Before I recommend spending money
on a battery and a couple other parts.
gregz
Nov 13, 2015, 2:47:49 AM11/13/15
to
so I have no idea, depends. I blew out my Harbor Freight charger, don't
know if it was something I did.
Start out slow charging the battery first before anything using one charger
and see if it cranks.
I can't see the chargers or schematics. It could be regulated chargers with
a 2 amp setting being lower voltage connected to ammeter. It's possible to
connect two supplies in parallel under certain conditions and depends on
circuit design.
Greg
Paint...@unlisted.moc
Nov 13, 2015, 4:43:09 AM11/13/15
to
On Fri, 13 Nov 2015 00:48:52 -0500, Micky <NONONO...@bigfoot.com>
wrote:
>I need a DC power supply, bigger than what I've got. Any reason why I
>can't connect two automobile battery chargers in parallel to suply the
>same vehicle?
I've used two battery chargers at the same time on cars many times.
Never had a problem. Of course I'm talking about two small chargers.
Like a 6 AMP and a 10 AMP. I would not connect two 30 or 50 Amp chargers
together. I'm just charging at a rate of 16 AMPS, which charges the
battery faster than the individual chargers. Since you can buy a 30 or
50 A charger, 16 A is still minimal compared to the bigger chargers.
Just sharing my experience, not guaranteeing you can do it safely. But
like i said, I've never had any problems doing it.
wrote:
>I need a DC power supply, bigger than what I've got. Any reason why I
>can't connect two automobile battery chargers in parallel to suply the
>same vehicle?
Never had a problem. Of course I'm talking about two small chargers.
Like a 6 AMP and a 10 AMP. I would not connect two 30 or 50 Amp chargers
together. I'm just charging at a rate of 16 AMPS, which charges the
battery faster than the individual chargers. Since you can buy a 30 or
50 A charger, 16 A is still minimal compared to the bigger chargers.
Just sharing my experience, not guaranteeing you can do it safely. But
like i said, I've never had any problems doing it.
pf...@aol.com
Nov 13, 2015, 7:01:46 AM11/13/15
to
On Friday, November 13, 2015 at 12:49:07 AM UTC-5, Micky wrote:
> I need a DC power supply, bigger than what I've got. Any reason why I
> can't connect two automobile battery chargers in parallel to suply the
> same vehicle?
>
YIKES!
> I need a DC power supply, bigger than what I've got. Any reason why I
> can't connect two automobile battery chargers in parallel to suply the
> same vehicle?
>
A few things about lead-acid batteries:
a) They do not like to be charged beyond about 10% of their AH rating. That is not to suggest that more amps will destroy them - but that some care is needed during the charging process.
b) Charging amps, AH ratings and the actual operation of the battery are, at best, first cousins - related but not directly. For instance, even a high-rated gel-type battery is generally not suitable for motorcycle operation as its chemistry is generally not suitable to provide the very fast discharge (very high amperage) needed to turn the starter motor at sufficient speed to start the engine. Conversely, a much lower *rated* battery may be perfectly fine for the purpose as its chemistry is designed for a very high amperage discharge for the few seconds necessary.
c) That your charger jumped to 10A is not a surprise, most such chargers are 'smart' inasmuch as they recognize the draw of the battery and react accordingly. But 10A is not hardly enough to turn the average small starter motor under load. For instance, a marine-grade Group 24 battery (most common group of that type) is rated at a mere 80 AH, but is capable of 800 CCA (cold-cranking amps) for a few seconds to start a big diesel boat engine, for example. Your little cycle-starter may need 50+CCA or more to operate properly.
d) A motor could care less how many amps are available to it, as long as they are in excess of its draw at a given load. If you want to test the starter, us a regular car battery. If you want to use an outboard device to test, get a Starter/Charger unit. These devices either have a rapid-discharge battery on board or a series of capacitors boosting the output the few seconds needed to start.
e) Ganging up chargers is generally not a good idea unless they are identical in behavior and type. It is generally not a good idea to use these things beyond their design parameters - at least, you would void any warranties. At worst, you would pick the only two chargers that if paralleled would go the way of Chernobyl.
Peter Wieck
Melrose Park, PA
philo
Nov 13, 2015, 7:50:38 AM11/13/15
to
On 11/12/2015 11:48 PM, Micky wrote:
> X
The only problem I can see is that most chargers today are automatic and
need to sense battery voltage before they turn on.
If the battery voltage is too low, the charger will not even turn on so
a non-automatic charger would need to be used to get the current flowing.
If the battery is /extremely/ low I've seen situations at work where
we'd have to put the battery on a variable charger and crank the voltage
quite high in order to get the charging process started...then after a
very short time switch the battery over to a conventional charge.
(As you probably know by now I was in the industrial battery business)
At any rate I don't recommend putting two chargers in parallel but on
the other hand I don't see that it would hurt anything just as long as
you disconnected one once the battery got close to 80% charged.
NOTE: To avoid a spark and explosion do not disconnect while under power
> X
> Given the way chargers are usually wire, will setting the charger on
> 10 amps provide more starting power than setting it on 2 amps? I
> would have assumed the answer was yes, but the ammeter went to 10 amps
> even in the 2 amp setting.
>
>
> And before anyone brings it up, I've been testing the kick starter
> too, and the ignition and fuel systems. I'm making mulitples tests,
> in order to test all the systems. Before I recommend spending money
> on a battery and a couple other parts.
>
The open circuit voltage of a charger means next to nothing.
> 10 amps provide more starting power than setting it on 2 amps? I
> would have assumed the answer was yes, but the ammeter went to 10 amps
> even in the 2 amp setting.
>
>
> And before anyone brings it up, I've been testing the kick starter
> too, and the ignition and fuel systems. I'm making mulitples tests,
> in order to test all the systems. Before I recommend spending money
> on a battery and a couple other parts.
>
The only problem I can see is that most chargers today are automatic and
need to sense battery voltage before they turn on.
If the battery voltage is too low, the charger will not even turn on so
a non-automatic charger would need to be used to get the current flowing.
If the battery is /extremely/ low I've seen situations at work where
we'd have to put the battery on a variable charger and crank the voltage
quite high in order to get the charging process started...then after a
very short time switch the battery over to a conventional charge.
(As you probably know by now I was in the industrial battery business)
At any rate I don't recommend putting two chargers in parallel but on
the other hand I don't see that it would hurt anything just as long as
you disconnected one once the battery got close to 80% charged.
NOTE: To avoid a spark and explosion do not disconnect while under power
Micky
Nov 13, 2015, 8:25:58 AM11/13/15
to
and my estate will be suing you if this proves fatal.)
Micky
Nov 13, 2015, 8:54:28 AM11/13/15
to
On Fri, 13 Nov 2015 06:50:32 -0600, philo <ph...@privacy.net> wrote:
>On 11/12/2015 11:48 PM, Micky wrote:
>
>> X
>> Given the way chargers are usually wire, will setting the charger on
>> 10 amps provide more starting power than setting it on 2 amps? I
>> would have assumed the answer was yes, but the ammeter went to 10 amps
>> even in the 2 amp setting.
>>
>>
>> And before anyone brings it up, I've been testing the kick starter
>> too, and the ignition and fuel systems. I'm making mulitples tests,
>> in order to test all the systems. Before I recommend spending money
>> on a battery and a couple other parts.
>>
>
>
>
>The open circuit voltage of a charger means next to nothing.
>
>
>The only problem I can see is that most chargers today are automatic and
>need to sense battery voltage before they turn on.
>
>
>If the battery voltage is too low, the charger will not even turn on so
>a non-automatic charger would need to be used to get the current flowing.
>
Not even an override switch? That seems like a bad idea.
>On 11/12/2015 11:48 PM, Micky wrote:
>
>> X
>> Given the way chargers are usually wire, will setting the charger on
>> 10 amps provide more starting power than setting it on 2 amps? I
>> would have assumed the answer was yes, but the ammeter went to 10 amps
>> even in the 2 amp setting.
>>
>>
>> And before anyone brings it up, I've been testing the kick starter
>> too, and the ignition and fuel systems. I'm making mulitples tests,
>> in order to test all the systems. Before I recommend spending money
>> on a battery and a couple other parts.
>>
>
>
>
>The open circuit voltage of a charger means next to nothing.
>
>
>The only problem I can see is that most chargers today are automatic and
>need to sense battery voltage before they turn on.
>
>
>If the battery voltage is too low, the charger will not even turn on so
>a non-automatic charger would need to be used to get the current flowing.
>
For example, the battery I started with, which I have only for testing
things, had a voltage of 0.1 or 0.2 volts, but I can usually charge it
to 11 volts or more. Actually I'm not sure the battery will help here
since it's sooo bad. But I'm stuck in the mold of my car, where the
oldest crummiest battery I ever had would still, when jumped from
another car, take a charge in about 5 minutes and spit it back to the
starter motor when the jumper cables were too thin to directly start
the car.
Somewhere I think I have an old motorcycle battery I also saved for
testing, but I haven't found it.
>
>If the battery is /extremely/ low I've seen situations at work where
>we'd have to put the battery on a variable charger and crank the voltage
>quite high in order to get the charging process started...then after a
>very short time switch the battery over to a conventional charge.
>
>
>(As you probably know by now I was in the industrial battery business)
Yes. I'm sure you know what you're talking about.
>If the battery is /extremely/ low I've seen situations at work where
>we'd have to put the battery on a variable charger and crank the voltage
>quite high in order to get the charging process started...then after a
>very short time switch the battery over to a conventional charge.
>
>
>(As you probably know by now I was in the industrial battery business)
>
>At any rate I don't recommend putting two chargers in parallel but on
>the other hand I don't see that it would hurt anything just as long as
>you disconnected one once the battery got close to 80% charged.
Okay. Once the scooter starts running, it has its own
>At any rate I don't recommend putting two chargers in parallel but on
>the other hand I don't see that it would hurt anything just as long as
>you disconnected one once the battery got close to 80% charged.
alternator/rectifier.
I'm told on a scooter forum that there are scooters that run on AC
current mostly and that they will start without a battery, but that
those that are DC won't. (or perhaps it's enough if they have a
charger connected.)
For the AC current scooters, seems to me, they should make AC
batteries. Isn't AC Delco a big maker of AC batteries?
philo
Nov 13, 2015, 9:38:24 AM11/13/15
to
On 11/13/2015 07:54 AM, Micky wrote:
>
> For example, the battery I started with, which I have only for testing
> things, had a voltage of 0.1 or 0.2 volts, but I can usually charge it
> to 11 volts or more. Actually I'm not sure the battery will help here
> since it's sooo bad. But I'm stuck in the mold of my car, where the
> oldest crummiest battery I ever had would still, when jumped from
> another car, take a charge in about 5 minutes and spit it back to the
> starter motor when the jumper cables were too thin to directly start
> the car.
If the battery was brought down to a very low voltage but charged within
>
> For example, the battery I started with, which I have only for testing
> things, had a voltage of 0.1 or 0.2 volts, but I can usually charge it
> to 11 volts or more. Actually I'm not sure the battery will help here
> since it's sooo bad. But I'm stuck in the mold of my car, where the
> oldest crummiest battery I ever had would still, when jumped from
> another car, take a charge in about 5 minutes and spit it back to the
> starter motor when the jumper cables were too thin to directly start
> the car.
a few days, it should recover (if it was OK to begin with)
However if a battery is left to sit "dead" for a very long time...once
stage 3 sulfation (permanent crystallization) has set in...there is zero
chance of it being recovered.
>
Tony Hwang
Nov 13, 2015, 10:41:22 AM11/13/15
to
Ian Field
Nov 13, 2015, 2:00:54 PM11/13/15
to
"Micky" <NONONO...@bigfoot.com> wrote in message
news:2kta4blrlhgi41b7b...@4ax.com...
> I need a DC power supply, bigger than what I've got. Any reason why I
> can't connect two automobile battery chargers in parallel to suply the
> same vehicle?
>
> Let's say one puts out 13.8 volts and the other 14.2. Is the first
> one really going to be a load on the second?
>
> What happens if they are both connected to a discharged lead acid
> battery that's now putting out 4 or 8 volts**? Won't that lower the
> voltage of the 14.2 charger to where it's not backcharging the 13.8
> charger? And won't the battery charge at rate of the sum of the two
> chargers, 2 (or 10) amps and 10 amps?
Way back when some power stations in the UK produced DC mains - some people
> can't connect two automobile battery chargers in parallel to suply the
> same vehicle?
>
> Let's say one puts out 13.8 volts and the other 14.2. Is the first
> one really going to be a load on the second?
>
> What happens if they are both connected to a discharged lead acid
> battery that's now putting out 4 or 8 volts**? Won't that lower the
> voltage of the 14.2 charger to where it's not backcharging the 13.8
> charger? And won't the battery charge at rate of the sum of the two
> chargers, 2 (or 10) amps and 10 amps?
charged their car battery by putting it in series with an electric fire.
These days; you need a pretty hefty bridge rectifier.
Ian Field
Nov 13, 2015, 2:03:48 PM11/13/15
to
<Paint...@unlisted.moc> wrote in message
news:jibb4b18fmta7a69c...@4ax.com...
charger involving 3x LV lighting transformers, all assembled in a cheap
steel tool case.
Can't remember which one or how long ago.
Paint...@unlisted.moc
Nov 13, 2015, 7:08:20 PM11/13/15
to
On Fri, 13 Nov 2015 08:25:49 -0500, Micky <NONONO...@bigfoot.com>
It wont be fatal for you, it's only 12volts. But it could damage a
charger or battery, although I have never had that happen. My chargers
are old, so they dont have all the circuitry that some new ones have.
It's just a transformer, some diodes, and a reset to shut it down in the
event of a direct short. Very simple, and I have fixed several of them
over the years. Usually it's a bad diode or two, or that reset device
fails. I did have one burn the transformer out, after it got rained on.
I learned that the hard way! I always cover them now if they are in use
outdoors.
charger or battery, although I have never had that happen. My chargers
are old, so they dont have all the circuitry that some new ones have.
It's just a transformer, some diodes, and a reset to shut it down in the
event of a direct short. Very simple, and I have fixed several of them
over the years. Usually it's a bad diode or two, or that reset device
fails. I did have one burn the transformer out, after it got rained on.
I learned that the hard way! I always cover them now if they are in use
outdoors.
Ian Field
Nov 14, 2015, 1:11:04 PM11/14/15
to
<Paint...@unlisted.moc> wrote in message
news:nbuc4b12bvjo4u534...@4ax.com...
the metal case is the only original part.
The rectifier was replaced with one from a motorcycle and the transformer
with one from a Philips black & white portable. The cheap & nasty plastic
moving iron current meter was replaced by an Admiralty bulkhead mounting
instrument.
A resistor was added before the rectifier to limit the current because a TV
PSU transformer doesn't have a charger transformer impedance characteristic.
A couple of big film capacitors were added to make the rectifier voltage
doubling (for some strange reason it actually gets up to about 42V with no
load!). Which works rather well for saving sulphated batteries. Later I
added a big fat electrolytic for zapping whiskered nickel cells.
gregz
Nov 15, 2015, 10:55:34 PM11/15/15
to
connection. I have a 4 amp one that's 30 years old, old trusty. I'll be
looking for another.
Greg
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