Reviving Bosch Drill Ni-Cad Drill Batteries Ask questions and find answers to many subjects relating to electrics and electrical work

[Mickeytix]

Hi,

New to this forum.....Did look for a tool section to post this but couldn't find one.

I have an old Bosch 12v cordless drill....Good condition but not used in years.....Charged both NI-CAD batteries but they literally won't even spin the drill once....I've watched a few youtube videos where they use an electrical connection to revive the batteries....Just wondering whether anyone has done this or has more info on it....Cheers in advance

[ericmark]

Yes but it is rather dangerous, what happens with NiCad cells is crystal grows and shorts out the cell, and the battery charger does not have enough power to burn the crystal away, so using a good battery in parallel with bad one can some times zap the crystals and bring them back to life.

However they can also go bang with dramatic effect, and even when you have got them to work, they don't work for long, and if you do it with a modern cell the bang is very large.

So yes possible with some cells, I personally would simply replace them, it is simply not worth the effort trying to get them to work.

[Mickeytix]

Yes but it is rather dangerous, what happens with NiCad cells is crystal grows and shorts out the cell, and the battery charger does not have enough power to burn the crystal away, so using a good battery in parallel with bad one can some times zap the crystals and bring them back to life.

However they can also go bang with dramatic effect, and even when you have got them to work, they don't work for long, and if you do it with a modern cell the bang is very large.

So yes possible with some cells, I personally would simply replace them, it is simply not worth the effort trying to get them to work.

Hi,

Thanks for your reply mate.......It's put me off trying, lol....Like you say they'd probably not run for long afterwards even if I was successful.

Think I'll look for new batteries.....Depending on the price I'll possibly treat myself to a new drill as you can get some good deals.

Cheers

[Toomanyjobs]

It's fairly easy to dismantle the battery pack and replace the cells. I would suggest replacing with NiMH cells - they're more tolerant of abuse and suffer less from 'charge memory' than old NiCad cells, and they can use the same charger (although it's not optimal).

Usually, the size needed is called sub-c

[ericmark]

I looked at new drill from Lidi and cheaper than new cells for old drill, using some thing like the AA cell often the electronics needed to charge the cell is built in, so a NiMh cell can replace a NiCad, but it does depend on the charger.

There are three common methods to charge NiCad cells, one is a temperature switch in the cells idea is electrical energy into chemical energy no heat, but once finished the it gets hot so once it switches off it latches off.

There is also the very low charge rate and warning charge for 12 hours only.

And there is the Delta V which uses the way the voltage slowly raises but once fully charged with constant current it drops again, and it uses this to switch off, advantage is the charger can work with different voltage batteries. However the drop in voltage with the new breed of battery is less than with NiCad so some old chargers will not switch off.

We have seen even when charger is correct how phone, plane, and electric car batteries have gone on fire, when Richard Hammond crashed an electric car it took three days to put the fire out.

It seems although we call the cell a Ni-Mh the way they work changes and some will give high power and others last a long time, and lithium-ion batteries are not same as Ni-Mh or NiCad but all sold as rechargeable batteries, and it is easy to get it wrong.

[Mickeytix]

Thanks for all the replies guys.......Think I may just treat myself to a new drill.....Will be lighter than the old Bosch I have.....Maybe I can sell the Bosch without batteries for £10/20 to put towards the new one.....Saw a few decent ones with good specs at Screwfix

DeWalt DCD776S2T-GB 18V 1.5Ah Li-Ion XR Cordless Combi Drill
COMPARE
2 x 1.5Ah Li-Ion Batteries
30min Charge Time
Max. Torque: 42Nm. = £99

Think I'm more tempted by this one though


Bosch 06019H1170 18V 2.0Ah Li-Ion Coolpack Cordless Combi Drill
COMPARE
2 x 2.0Ah Li-Ion Batteries
30min Charge Time
Max. Torque: 55Nm. = £129

[Mickeytix]

Bit random but..........I think I'm right in assuming that if I was to wire my old drill up to a 12volt supply then it'd work fine without the battery.....Just curious as I rarely use it and it'd be a temp fix..cheers

[Mr White]

It would depend on what voltage your current drill is. Too low and your drill would "go very fast" and not for long.

But if you are going to the effort of adding a cable to a battery drill, why not buy a mains powered drill in the first place? Less than £25, it will always work, even if you put it away for a few months, and no big heavy battery to move round.

[Mickeytix]

Thanks all for your replies.....I ended up getting this

Bosch GSB 18-2-LI Plus

18V 2.0Ah Li-Ion Coolpack Cordless Combi Drill with case/charger
2 x 2.0Ah Li-Ion Batteries
30min Charge Time
Max. Torque: 55Nm

For a great price......£102

Thanks again