Cordless Drill Battery Rebuild\Recell?

[Dibs-h]

Has anyone replaced dead cells in a cordless drill/etc battery pack?

Most of my Makita NiMh packs are dead and having taken one apart, I've identified what I believe is one dead cell. So thinking of removing it and soldering\welding in a new one. Just wondering if anyone has done similar and their results\experiences? i.e. has it worked, for how long, etc.?

Cheers

Dibs

 

[MikeJhn]

Yes it works, but the replacement cell must be the same capacity as the one you are replacing and use a very hot iron so heating the cell is kept to a minimum, the only problem can be another cell going down straight after, NiMh cells are cheap enough that replacing all of them is not too expensive, now days I would replace with Enerloop NiMh cells, they hold their charge much better and don't require any special charging arrangements.

Mike

 

[Fergal]

I did it once, but replaced all the cells as they were pretty cheap. It lasted a while, but then another drill came along with Li-Ion batteries, so I got that instead. Li-Ion powered drills are far superior to the old NiCad/NiMH versions IMO. With the availability of cheap cordless drills from Aldi/Lidl etc, they've become almost disposable as it's cheaper to buy a whole new drill with batteries, charger etc than just the batteries on their own.

 

[Dibs-h]

Yes it works, but the replacement cell must be the same capacity as the one you are replacing and use a very hot iron so heating the cell is kept to a minimum, the only problem can be another cell going down straight after, NiMh cells are cheap enough that replacing all of them is not too expensive, now days I would replace with Enerloop NiMh cells, they hold their charge much better and don't require any special charging arrangements.

Mike

I was initially thinking of replacing just the dead cell, but am coming round to the idea that the whole pack won't be balanced and will fail again, so better off replacing them all.

Found a video on Youtube of a guy who knocked up a spot welder for peanuts and not much in the way of parts - https://www.youtube.com/watch?v=o1NFbchHeM8 so ordered some nickel strips and a solenoid off Ebay.

The Makita batteries are 2600mAh and I've found a firm that supplies 2500mAh ones for under 2 quid each - so might recell one pack completely and see how it goes.

I did think of buying a LiOn set but at around 250 for a similar set, I thought sod it, might as well give rebuilding the existing packs a go, or at least one.

I'll post up a thread of how I get on, or update this one when the bits turn up.

Cheers

Dibs

 

[MikeJhn]

The problem with LiOn batteries is that they can't be charged with an ordinary charger or a charger that has been supplied with the NiMh cell drill you already have, for a start each cell is a higher voltage than a NiMh cell and the current requirements for charging are also different, each cell should be charged individually to keep the cells in balance.

Mike

 

[Dibs-h]

The problem with LiOn batteries is that they can't be charged with an ordinary charger or a charger that has been supplied with the NiMh cell drill you already have, for a start each cell is a higher voltage than a NiMh cell and the current requirements for charging are also different, each cell should be charged individually to keep the cells in balance.

Mike

Sorry - I meant in moving across to LiOn I would have to buy a whole new drill\impact driver set as my existing drill\impact driver & batteries wouldn't work with them.

A comparable drill\impact Makita set is 250 quid with 2 batteries (and the charger).

Whereas I should be able to completely recell a pack for under 30 quid.

Cheers

 

[Raymond UK]

It's worth a shot.

I've done it in the past and it worked well. I tried to hold off as long as possible to move to Li-Ion just because I had so many Ni-Cd / NiMH Makita stuff.

Just decided one day last year to sell all and move to Li-Ion. It's a different world.

Old Makita stuff still holds quite some resell value too.

 

[finish_that]

You can buy "Floureon" Makita style batteries for very good prices , actually the same price or less than buying individual cells, I got some for my 12v Makita stuff and they work perfectly
even with the mini SDS I have, actually the 12v stuff is great , not too big and very cheap to pickup as long as you get the non abused, or totally worn out kit, I have right angled frill , impact driver , torch and the wonderful HD160 tiny SDS drill - all great for hobby use whilst still being pro kit built to last.

 

[sunnybob]

I've had the flouron red batteries for my makita 18 volt drill for over 2 years now. A fraction of the makita prices and somewhere around 95% as good (I find they run down just a little bit quicker than the makitas). I have three of them and am well pleased.

 

[Eric The Viking]

You can easily buy tagged cells (solder tag spot-welded to each end). It's a much easier job re-celling with those than trying to DIY the actual battery conections, and you can usually use thicker wire too, which helps performance in motor and other high current applicstions (such as my flashgun batteries).

I have a right-angled drill/driver, which is invaluable on the rare occasions it's needed. After Mike's recommendation, I'm going to look at eneloop cells (although it's currently NiCd so I will need to check the charger etc.). Even though the pack won't be cheap, it's still better than replacing the tool, and greener too.

If you do decide to re-cell, check the new cells' voltages before assembly: using bare wires, it's too easy to short a cell whilst trying to get everything fitted back in. It doesn't do them much good, and you can weld with good quality D-size NiCds (DAMHIKT).

I have found insulation tape to be of quite limited value in some cases (the flashgun packs, for example, have only fractional millimetres of clearance and are really awkward). Sellotape is thinner but fragile, although once assembled into the right bundle, the cells usually behave.

 

[Raymond UK]

I have a right-angled drill/driver, which is invaluable on the rare occasions it's needed.

I still have my 12v (old style battery) Makita angle drill. Very good tool indeed. This and my 9.6v Makita stapler are the only tools I haven't upgraded to Li-Ion. And by the looks of prices for both it'll stay like that.. :shock:

 

[MikeJhn]

Eric

A touch of CA on the outer case of each cell will hold them in place much better, you can then assemble the pack back into the case and insulate over the top and bottom of the cell with thick paper, once the case is closed the cells are safe.

I have re-celled with Li-ion and installed external balance leads to charge the cells from my dedicated 6cell Li-ion charger, the charger cost more than the tools. :lol:

Forgot to mention I also use LiFe and LiPoly cells as well. :wink:

Mike

 

[user22161]

These people were recommended for rebuilding battery packs on another forum, I've not used them so no personal knowledge. http://www.combatalexander.co.uk/main/c ... gory_id=11

 

[Lazurus]

I used to do a lot of similar rebuilds for model aircraft power packs. I always used overlander for cells and wire and shrink-wrap etc. I have done a couple of packs for my Makita in the past, now I just buy a Chinese copy pack and consider it disposable.

 

[Alexfn]

If you check online there should be an adapter that can be 3d printed. You can order it and have it printed and delivered to you. Allowing you to use li-ion batts. Then you can also slowly move to li-ion tools.

Otherwise yeah id recell the whole pack not just one cell

 

[Eric The Viking]

That would need a very specialized charger and a different connector to be fitted, too (so they can be charged individually). Sounds a bit A-level to me, and possibly expensive...

 

[Alexfn]

Think you misunderstood