I have been given a Nu tool cordless electric drill , with a spare battery but no instrucion book , the batteris are 20.4 volts, my question is how long do I charge a flat battery for ?.
battery charging time
- Thread starter 1JACKOFALLTRADES9
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Quite a science in its own right and much can depend on how efficient the batteries are, but very roughly....(NiCads)
Divide the battery power in mA
By the charge rate (shown on the charger) in mA
Gives you the hours required.
In real terms, usually between 12 and 18 hours. If the batteries are elderly, they'll charge up much quicker but discharge just as fast.
With NiCads its a good idea to have them fully discharged before the charging cycle begins.
(I hope I remembered that correctly!)
John
Divide the battery power in mA
By the charge rate (shown on the charger) in mA
Gives you the hours required.
In real terms, usually between 12 and 18 hours. If the batteries are elderly, they'll charge up much quicker but discharge just as fast.
With NiCads its a good idea to have them fully discharged before the charging cycle begins.
(I hope I remembered that correctly!)
John
just be aware 2-5years is a normal useful life for batteries in good condition dependent on battery quality
if the batteries are used occasionally they will tend to fail sooner but not always
as burnerman says trickle charge will be around a day
a good charge is 30 mins- 1h suspect yours will be between 3-5hrs but as said no way off telling but dont worry it will be automatic and the light will change either colour or flashing to constant unless off course its trickle charge then 24hrs it is
if the batteries are used occasionally they will tend to fail sooner but not always
as burnerman says trickle charge will be around a day
a good charge is 30 mins- 1h suspect yours will be between 3-5hrs but as said no way off telling but dont worry it will be automatic and the light will change either colour or flashing to constant unless off course its trickle charge then 24hrs it is
Quick answer, the battery pack will be fitted with an overcharge protector, this will kick in when the battery is fully charged!
Now for the reality...if your cordless battery has been left idle for a long time its poss that the self discharge of ni-cd cells will have reversed the polarity of the pack (don't ask) to get it working again you need to give it an" electric shock" (12v from a car battery or similar. Pop a search on your favorite search engine [shocking a ni-cd battery back to life with a car battery] Once you've done this (works for batteries that are giving bad output yields also) charge & drain your twice (twist a bit of copper wire round the trigger/handle) then recharge, bearing in mind the info given above
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Thanks for info, I shall try charging for 1 hr and see life it puts in the battery.
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