Can't find the inst---sheet ; battery tools TOOL LIFE span

Old 10-25-17, 01:54 PM
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Cool Can't find the inst---sheet ; battery tools TOOL LIFE span

I leave my sears electric screwdriver plugged in all the time, ; l don't use it much] and my sears Drill the same way.It.has the in handle battery. Here it is???; Do You unplug -------yours, each and every time.? I find now after sometime has past , My screw driver doesn't last thru a job----compared to when new, its dead in an hour or less.Drill is abit better- but not by much, Is leaving then plugged in a BAD DEAL? for these tools.batteries? thank you much for any help you can show me bob s
Old 10-25-17, 04:59 PM
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Rechargeable batteries work better when they are allowed to run down fully then recharge, they dont get that short term recharge memory.

So yes, better to charge it up, get it off the charger, use it till dead, then recharge!
Old 10-25-17, 06:07 PM
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There is also a difference between chargers. Better chargers will switch to a trickle to avoid over charging. Simple battery tools will usually not have complex chargers.

As for the practice of running them down to flat before charging I have heard varying opinions. One explanation I read advised to put them on charge the moment you sense they are losing power. The explanation was, these batteries are actually multiple cells and all are not equal. If one goes flat before the others it will have current forced through it in the wrong direction which can kill it. Once dead it cannot recover.

The toughest part for battery powered tools is not being used. Either setting unused or setting on the charger is probably not good.

Old 10-25-17, 06:16 PM
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Thank you Bud and Marq! for your replies. I will follow your leads in both cases, and get a Trickle charger for it also, Trickle chargers are cheaper than theses batteries are. again thanks bob s
Old 10-25-17, 09:49 PM
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It all depends on the type of battery. A Ni-cad (older tech) should be unplugged when its done charging. It should also be used until it visibly starts losing power and then fully charged. Or it can be used and left partly charged if it will be used again soon. If left off charge but not used, it can develop memory as it slowly discharges and never have as much capacity as when new.

Li are different as they are very heat (and impact) sensitive. Even the cheapest Li charger/battery pack has protection built in and will cut off when fully charged. Since Li can be left fully charged for long periods, it''s not as vital they be used often, but at least once a month they should be exercised. They will not develop memory and may be recharged as necessary prior to a project. You should never pull a hot battery right out of the tool and throw it in the charger. Let it cool to room temp first.

These are general statements. Every manufacturer has their own recommendations. Instructions should be available online at

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