Leave drill battery on or off drill?

[TOM KAN PA]

When I store my cordless drill, should I remove the battery from it, leave it on, or is it six to one, a half dozen to the other.

[Joe Bobst]

Why wear out the latches and contacts prematurely? If the switch works properly the battery is isolated. FWIW, I vote for leaving it on.

Joe

[MrAoD]

Consult the manufacturer's recommendation. Most, IME, recommend leaving the battery in the charger, provided the charger has the overcharge/overheat sensor circuit.

Best,

Marc

[John]

I disagree - most cordless drills use NiCad batteries which have memories so should be drained before they are charged. Leaving the battery in the charger will result in it being frequently "topped up" by the charger as it naturally discharges and will reduce it's life and the amount of charge it will take.

Leave the battery in the drill until it is almost fully drained.

John

[jim]

just leep the battery on the charger so when you want to use it you will have a charge on the battery.....

[Mike Dobony]

"John" will take.

Except for the new Dewalts and Milwaukees. They have memory free batteries. You can charge them whenever you want. However, it is still better to just leave them on the tool and have the second ready to go. It only takes an hour to fully charge a dead battery anyway, 45 minutes with the Milwaukee's triple charger. As far as the other brands, you are correct, the NiCads need to be fully drained before recharging or else they develop a memory and will not be able to be fully charged.

-- Mike D.

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[Mike Dobony]

"John" will take.

Forgot that NiCads also do not loose their charge very quickly, as opposed to the NMH that are memory free, but quickly loose their charge.

[Bruce]

I've had a cordless 12v DeWalt drill since 1998 and I have always left the battery on when not using it. In fact, the battery stays on until it is drained. The spare battery always stays in the charger which is plugged into the wall. Not sure if this is good or bad but it is what I have done. No worries so far.

-- Bruce

PS -- Still using the same 2 batteries that came with the drill and I've used (and abused) the drill quite a bit for driving deck screws and making holes.

[George E. Cawthon]

Keeping it attached should not result in any drain, so it doesn't make any difference if the pack is attached or not, unless you have some light or electronic readout on all of the time.

And the saying is six OF one and half a dozen OF the other. The preposition TO doesn't make sense.

Seriously, leave them attached unless instruction for that particular brand say otherwise. Even cheap batteries don't discharge that rapidly. OTOH, the tendency for many home owners is to ignore the batteries which sit for varying long period and just die. Or, they let them sit, and then charge them for long periods (forget them) and way over charge them, damaging the battery pack. If you have a precise up to date well controlled charger, you can just let them charge, but most chargers are not that good. The best bet is a maintenance program whereby you check the voltage of the pack periodically and when it reaches a certain point you recharge the pack.

Forget all the stuff people tell you about memory and discharging the battery pack. You should never discharge the pack below 1 V per cell or you are likely to damage it. And a cycle is a cycle and a battery pack has only a certain number of cycles in it, so don't every discharge just to discharge; discharge because you are using it and don't let it get hot. Remember; never less that 1V per cell. In practice, that number should be much higher and could be as high as 12V. When you tool is getting obviously getting weak, check the voltage and that is the voltage that you don't want to go below.

The biggest problem with battery pack is overcharging, heat kills quickly. So if your instructions say to fully charge in 4 hours, never charge more than that, and if you use the tool only a little and want to recharge, recharge for only an hour or so. Check the voltage after the pack sits unused for several hours and charge some more if needed. A fully charged 12V pack probably reads around 13.2 volts. Check the battery pack every month and charge it. You should charge about once a month if you don't have and accurate trickle charger (and most aren't accurate). Good Luck, and if you need more information just do a google search on Battery Memory and only read the ones that are from universities, Government (e.g., NASA), or battery manufacturers. Good Luck.

[mark Ransley]

George I agree with you except nicads should be stored at what is discharge 1v . Lead acid store fully charged. ni mh I dont know.

[Mike Dobony]

Regardless of the voltage, when the drill noticably looses power it is time to recharge it. But again, follow manufacture's instructions. Forget that "man" stuff and read the manual!

[George E. Cawthon]

Don't think I understand that. In storage, the pack constantly loose voltage through internal discharge. My understanding is that as they go below 1v per cell, the weakest cell is likely to reverse polarity and that will ruin the battery. I keep mine charge above 12v by checking every 4-6 weeks and charging before they drop below 12v.

I do the same with my lead acid batteries and charge them to

12.7v and while in storage charge them whenever they drop to 12.5v and never let them dr>

[George E. Cawthon]

I agree, when it loses power it's time to charge, but I check the voltage more to establish a minimum voltage when the batteries are stored. What is "man" stuff? Some tools come with little more than a list of parts and don't give any useful instructions about battery charging. They are often as useful as new car driver manuals that say "see the dealer."

[Trent©]

I didn't realize that a 12v. drill could run at 1v. lol

Are you sure you really mean to talk about voltage?

Wishing you and yours a happy Thanksgiving season...

Trent

[Trent©]

The battery will loose some of its charge...it DOESN'T loose voltage, btw...just by sitting. Removing it from the drill won't stop that process. The proper thing to do is keep it in the charger if you don't have a spare battery.

And leave WHAT on?

And its 'six one way...half dozen the other'.

Wishing you and yours a happy Thanksgiving season...

Trent

[mark Ransley]

Voltage Reversal I thought couldnt happen till 0.1 volt , being severe discharge. I have 20 yr old packs still operational . I store at apx

1v a cell .

[Chris Lewis]

According to Trent© :

He did say "per cell", did he not?

[tnom]

If you are talking about a NiCad battery being stored for a month or more it is best to leave it in a some what discharged state. 40% of its full charge is usually recommended.

A combination of constantly topping it off and not using/discharging it will ruin the batteries life quickly.

[George E. Cawthon]

Forty percent of full charge puts it below 1V per cell, which will result in a good chance that the weak cell will reverse polarity. That will kill the pack or lead to early death. For example, a 12V pack that measures 13.2V at full charge will measure 5.28V at 40% charge, which is extreme. I just checked two pack and one read 13.05 and one read 13.11 after sitting for at least 10 days. My packs don't lose enough voltage to require a charge more often than once every 30-45 days. That is constant topping off. In any case, topping off isn't destructive, it's overcharging

Topping off the battery, if you mean charging to its full capacity but no more, isn't going to ruin a battery. In fact, that is exactly what the best chargers do. And not using/discharging it won't ruin it quickly either. Not using it does ruin batteries if you mean leaving it alone because when internal discharge goes below 1V per cell, a cell is likely to reverse polarity. All of my reading and my limited experience of nicads (about 10 years) indicate that overcharging and deep discharging (anything below 8V for a 12V pack) are the main culprits for ruining battery packs. I've found that individual AA cells used in walkman type tape machines that discharge to about 1.25 V and then are removed and continue to discharge to less than 1 volt have very short lifetimes and successful recharge cycles. Good luck with your 5.28V storage of 12V packs.

[George E. Cawthon]

Oh Trent! As the battery loses charge, it loses voltage. It may not tell you the exact amp-hours left, but it pretty well tells you the state of the charge, i.e, whether it is

90 percent, 80 percent, etc.

Leave the battery on the tool

No it isn't! It's six of one and half a dozen of the other.

Same to you.