Charging Cortdless drills etc batteries

NiCad - do not recharge unless fully discharged otherwise they develop a "memory" for a less than full change. What I do is when the battery is getting low, I run the drill until it will no longer turn & then fully recharge. You will also find that a fully charged battery will discharge slowly even when not being used. Do not be tempted to recharge - just use it until flat & then recharge fully.

LiIon - recharge at any time although they do suggest you do not run them completely flat.
 
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NiCad - do not recharge unless fully discharged otherwise they develop a "memory" for a less than full change. What I do is when the battery is getting low, I run the drill until it will no longer turn & then fully recharge. You will also find that a fully charged battery will discharge slowly even when not being used. Do not be tempted to recharge - just use it until flat & then recharge fully.

LiIon - recharge at any time although they do suggest you do not run them completely flat.
I made a similar enquiry a little while ago about my laptop battery which is Li-ion apparently they are OK to leave on a charge more or less permanaently but perhaps letting them fully discharge once in a while. NiCad are best fully discharged then fully re-charged. However the info I've had with a replacement for my battery drill is not to overcharge them. I have a timer now and only charge for 3 hrs.
I've searched for the previous thread as it had a lot of useful tips but can't find it.
 
Nicads are pretty tough, but it depends on the charger you use. A nicad has a volt peak just before full charge so a peak charger will detect this and move over to trickle charge. As to memory effect.. think it is damn hard to prove it with modern chargers and nicads. Nicads have a sharp drop off rate, so their draw back is they suddenly lose power, quite fast. A bit more tolerant of over discharging, but too low and you bu\\er it.
Lithium is much more unstable; you dont want to mess around with high discharge /higher voltage batteries. A phone might be ok, but bigger batteries can indeed catch fire, and good luck putting it out.
Still,you have to be a muppet to get yourself into that situation, but I would ALWAYS use a decent lithium charger do not use any other charger.Unlike nicads , lithiums dont discharge much at all, so they are great for that infrequently used drill ...
So nicad , cheap heavy almost indestructible. Lithium light,high power,expensive . Oh, if the cell voltage drops too low, it wont recharge, so a decent bit of kit has low voltage protection and a decent controlled charger.
Best tools I have are all lithium . or li/ion, I guess to be correct.
But they are expensive and we all managed happily with nicads for many years.
 
SNIP

Lithium is much more unstable; you dont want to mess around with high discharge /higher voltage batteries. A phone might be ok, but bigger batteries can indeed catch fire, and good luck putting it out.
Still,you have to be a muppet to get yourself into that situation, but I would ALWAYS use a decent lithium charger do not use any other charger.Unlike nicads , lithiums dont discharge much at all, so they are great for that infrequently used drill ...
SNIP

I guess Boeing qualify as muppets :D
 
Lithium batteries can be a devil to try to recharge fast ie a few hours. Yes they can catch fire and do horrible things.
If you are trying to make up a charger yourself safest bet is to make the charger very low current long charge. ie at least 24hrs.
Nicad are now nearly all replaced by NiMH which are better at the memory problem.
As I understand it is not good to completely discharge a battery of Nicad or NiMH cells. The problem is that one cells goes to zero volts first and the current that then flows through it tends to charge it in reverse which causes dendrites to grow which short circuit the cell. So it can't be charged. The best bet is to completely discharge each cell alone. Not easy with a battery. Nicad/NiMH go realy well asa single cell battery as in electric toothbrushes where you do discharge the cell to a very low voltage.
If you dismantle a Nicad/NiMH battery because of performance it is almost certin that one or more cells will not charge and have in fact an internal short circuit. You can try fusing this by apply several volts at high current in the correct polarity to the cell. one second is long enough. Check with a volt meter and if you are successful you will measure some voltage which will quickly rise to 1.2 when you charge it. Yes I have used a car battery but be careful you don't wan to explode the cell. About 5 amps is usually enough. good luck olewill
 
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