Duration of 1st charge of drill battery

Mar 01, 2007 8 Replies
A

My portable Tesco drill has a 9.6V 1000mAh battery pack. I don't know what type of battery it is. The power supply "brick" outputs 12VDC



400mA to the charging stand which the battery sits in.

The instructions say to charge it for about 5 hours each time it gets run down ... not to carry on charging because the charger does not switch off when the battery is full ... 10 hours is the maximum permissible.



Should the first charge be for a longer time to equalise the cells so they are all fully charged. Maybe, 16 hours? Or would this be too damaging?


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D

16 hours looks like a substantial overcharge. If the DC supply is actually delivering 400 mA, then a 1C charge time for a 1000 mAh pack would be only 2.5 hours... throw in some losses and inefficiency and I'd expect that 4 hours probably tops the cells up pretty well. The 5-hour number they give is probably quite reasonable. Anything much beyond that, and you're simply trying to force current through fully-charged cells, and heating them up as a result.

Even if the cells aren't *perfectly* matched in the pack, I'd expect them to be within perhaps 10% of one another. A 6-hour charge ought to be adequate to ensure full charge even if there are differences between the cells.

Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads!
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E

Follow the manufacturer's instructions. Ed

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M

almost certainly low end NiCd

lord no, 5 hours is a heavy enough charge already

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D

Most of these cheap drills with even cheaper chargers seem to recommend a stupidly long initial charge. Perhaps they want to make certain the rot sets in early.

A 5 hour charge type suggests all the 'control' consists of is a series resistor between an unregulated DC supply and battery, so the likelihood of overcharging is pretty real.

*I'm pretty sure that sex is better than logic, but I can't prove it. Dave Plowman dave@davenoise.co.uk London SW To e-mail, change noise into sound.
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X

I have one of these drills. As soon as you start it up you can heae it slowing down. Its battery is absolutely inadequate.

For full context, visit https://www.homeownershub.com/uk-diy/duration-of-1st-charge-of-drill-battery-378764-.htm
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R

Xerxes wrote

You are only 15 years late.

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A

As the original post was 15 years old either your drill is also of that age and the battery is at the end of its life or if purchased recently it probably has a completely different battery technology.

mailto : news {at} admac {dot} myzen {dot} co {dot} uk
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L

You need a new battery.

Don't leave this battery chemistry in the dumb charger.

There are relacement parts for most old battery packs, including nicad.

RL

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