Cordless Drill Voltage Question
Harry T. and Pam N. Stone
related more to power level than to charging abilities. I used a 9.6
volt Makita for a number of years and keep a 12 volt fast charger on the
truck dash all the time. The higher the voltage the more time and power
the drill will deliver. The other side of that coin is that the cost
rises. I reccommend you buy a name brand and a 12 volt fast charger.
Charge the batteies with shore power and use the 12 volt charger only to
recharge the batteies if you have exhausted the charge. DeWalt, Makita,
Skil, Millwaukee are all good products. A assortment of screw bits
(Phillips head, Straight, and Hex) will be a great timesaver.
Good luck and Happy Boating
H.T.
Steve Martin
we go cruising and would like to be able to recharge the drill's batteries
from the boats 12V system. My question is, should I get a 12V drill and
recharge it using the boat's charging system (solar panels) or should I get
a 9.6V drill, which seems like it could be recharged directly from the boat's
12V system? Anyones experience on the subject would be welcome. Thanks.
Steve Martin
Steve Martin
understanding that a 12-volt fast charger is a charger that is available
that runs on 12V (rather than a charger for charging 12V batteries)?
Steve
cusdn
Makita offers a 12v auto charger for their systems. If the 12v drill is
avialable with the auto charger I would get that one as it is more
powerful. I have never understood why the companies have not made one
that would draw off of an auto battery directly as the power off
a deep cycle battery would run anything.
Bryon Kass
Custom Design in
THE ENGINE ROOM http://www.ici.net/customers/cusdn
Andrew Case
Steve Martin <csm...@pitt.edu> wrote:
>Am I correct in
>understanding that a 12-volt fast charger is a charger that is available
>that runs on 12V (rather than a charger for charging 12V batteries)?
I talked to a DeWalt representative a few weeks ago about this, and
he said that DeWalt has a charger which charges their 12V batteries
and runs off 12V DC. It can only be had a separate item, though (i.e.
you can't buy a drill with the 12V DC charger instead of a 120V AC
charger). I'd suggest getting a drill with adjustable torque and
a selection of screwdriver bits, too.
......Andrew
--
Who are the Little Furry Daughters of Xenu?
Bernard W. Joseph
When the 7.2V battery in my Makita drill motor died, I took the tool
apart and simply connected a wire that I could plug directly into 12V.
It works like a charm: the sucker really drills.
I realize that the motor isn't made for 12V, but having been a ham
radio operator for 40 years, I learned that you can overload
eceltrical things, as long as you don't run them until they smoke.
P.S. I got this tip from a boating friend. I've forgotten which one,
otherwise I'd give him credit.
RECARTER
You can't charge a 12v drill directly off unregulated ships power,
you'll toast the batteries if you try. You are better off with a 9.6v
drill, but it is almost impossible to find a 12v to 9.6v charger though.
You can make one yourself, or use a small inverter to supply 120v to the
charger, in which case you could use the 12v drill.
Phill Klein
In article <31D495...@pitt.edu> Steve Martin <csm...@pitt.edu> writes:
>From: Steve Martin <csm...@pitt.edu>
>Subject: Cordless Drill Voltage Question
>Date: Fri, 28 Jun 1996 19:32:43 -0700
>I am thinking about buying a cordless drill to take aboard our boat when
>we go cruising and would like to be able to recharge the drill's batteries
>from the boats 12V system. My question is, should I get a 12V drill and
>recharge it using the boat's charging system (solar panels) or should I get
>a 9.6V drill, which seems like it could be recharged directly from the boat's
>12V system? Anyones experience on the subject would be welcome. Thanks.
>Steve Martin
How about buying a cheap inverter to plug the 120V battery charger into. I
have seen 100 Watt units in the $50.00 price range. This would enable you to
buy whatever cordless you want, charge if while on the boat and have the
inverter to charge other things as well (such as a laptop computer)
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Phillip Klein Internet pkl...@interaccess.com Compuserve 75600,1023
Gleeson, Sklar, Sawyers & Cumpata LLP Skokie, IL 60077
Voice: (847) 673-4500 x323 Fax: (847) 673-3949
COnant Webb
I've been using a makita 9.6V drill aboard for three years without
any problems. Makita sells a 12v charger that I run off the boat's
12v service. Take several spare batteries and don't expect them to
hold a charge for months.
RECARTER
This is precisely what I do with mine. It is not very power efficient
however. If power consumption is a consideration, you are better off
finding some way to charge it directly from ships power.
I used to run my laptop through a small inverter. Efficency was less
than 20% operating in this mode. The inverter drew 4 amps when running
the laptop. I now plug the laptop directly into the ships 12v system.
Average consumption is now less than 1 amp.
Charging a drill isn't as big a deal as running a laptop. You can
probably only charge it when the engine is running.
Tim Margeson
In article <4r39ib$e...@bashir.ici.net>, cu...@ici.net says...
>
>I have never understood why the companies have not made one
>that would draw off of an auto battery directly as the power off
>a deep cycle battery would run anything.
>Bryon Kass
IMHO, there seems to be few electronic engineering folks in this group at this
time. So I'll add my three cents worth.
The major reason for NOT having a 12V drill motor without batteries is the
same reason they started putting small batteries in them in the first place.
It's called portability.
Personally, I'd hate having to have an extension cord just to carry a drill up
to the spreaders.
Battery packs come in various voltages, 1.2 volt steps for Ni-Cads. Ten cells
makes a 12V battery. These are not very good to charge directly from a 12.6V
wet cell lead-acid. Manufacturers sell 12v chargers that in some cases invert
to the voltages required to fast charge Ni-Cads. Chargers for 9.6 and 7.2 volt
systems can be direct, hence more efficient.
In terms of Watt-hours saved using a direct versus inverted charger, a 12V
pack of C cell batteries has about 18 Watt-hours of capacity (10 cells,
1.2V*1.5 Ah each). That's the same as drawing 1.4 amps from the ships
batteries in one hour. Considering how infrequently we use drills on
voyages, we are talking small potatoes overall. If you include charger losses,
total recharge for a 12V Makita is less than 2.0Ah from the ships stores. My
7.2V model takes about 1.5Ah using a 120V charger and my boats Freedom 10
inverter.
I recommend, if you don't already have an inverter, using a small 300W
inverter which has many other uses like charging handhelds and other loose
Ni-Cads, etc. It costs about the same as the special 12V version of the
battery charger.
As far as overall battery usage, there is no real power savings to be had
charging small batteries. In some low voltage chargers, the step down from
12.6V to 9.6V or 7.2V is done via linear devices, and the extra voltage
(12.6-9.6=3.0V), is dissipated in the linear device. This loss is 24%, making
the efficiency 76%. If the 12V charger is a really good switcher of some kind
- expect to pay lots - the efficiency will at best be 80%.
As another thing to think about, my Freedom 10 runs my 1/2 inch drill just
fine, and only it will drill a 6" diameter hole to install access panels.
Well, my account just logged me off for inactivity, so I better close.
--
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Tim Margeson timo...@pacifier.com
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