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Anyone Converted NiCad drill to Lithium Batteries?
John P - 27/3/21 at 12:49 PM

Hi,

I have a Site/Makita drill which came with three 18 volt NiCad batteries and a charger in a very robust case and this has been excellent until recently when the batteries slowly died.

Although you can get new batteries the cost is such that it doesn't make any sense so I went and bought a new DeWalt 18 volt Lithium drill which is OK but not as good as the old Site/Makita one.

Before taking the old drill down the dump has anyone used an adaptor to allow a DeWalt battery to be used with a Makita type drill? I have seen some references to this on line but haven't actually found exactly what would be needed. The advantage would be that I already have the DeWalt Lithium battery and it's charger so the only cost would presumably be for the adapter.

John.


baz-R - 27/3/21 at 01:39 PM

have you considered getting new cells for the old batteries?

i have revived old expensive tooling and test equipment by just renewing the cells or making up new reachable battery's

you can also find a lot of pattern or copy battery packs for the major powertools


SPYDER - 27/3/21 at 02:01 PM

Last year I looked into nicad cell replacement for my 18v Snap On drill. County Battery quoted £48.
I just looked at their website and 18V 3aH Nicad is now quoted at £53


obfripper - 27/3/21 at 02:34 PM

The adaptors should work fine to operate the tool, but most li-ion cordless tools have battery protection in the tool so care is needed to not over-discharge the battery pack as most of the adaptors are just passive connectors, and the tool will have no protection as the ni-cads needed to be ran til flat before charging.

I've not seen the combination you require, so you would likely need 2 adaptors, one from dewalt xr to makita lxt , and one from lxt to makita ni-cad.

It's possible to 3d print one if you can or know someone who can, you could also use the upper shell of your old battery pack with a 3d printed lower section to connect with the dewalt battery, leaving you with less to design/print.
There doesn't appear to be a direct adaptor for download, but it should be quite possible to merge existing designs on thingiverse to match.

Dave


daviep - 27/3/21 at 07:46 PM

I 3d printed bases for my old Dewalt 18v to fit Aldi / Lidl batteries, just went rough and ready with soldered tails between the original tool battery connections and adaptor and then sikaflexed the adaptors to the bottom of all the tools. It works a treat the difference in performance is better than I expected both in terms of run time and actual power, especially the 1/2" impact gun.

Cheers
Davie


ianhurley20 - 28/3/21 at 08:23 AM

I've done a couple of battery packs where I have removed the old NiCads and replaced with 18650 litium batteries, the type which comes with a BMS in each cell. They work very well indeed. The ones I did were 14.4 volt ones which I put 4 x 3.7volt litium batteries into. Not exact but near enough. They were very much lighter and took less space so some internal structure to hold the cells steady was needed. With an 18 volt tool I would probably try 4 cells and 5 to see which was best


John P - 28/3/21 at 09:04 AM

Thanks for all the feedback.

I've taken one of the batteries apart but it looks as though it would be quite difficult to replace the cells with NiCad replacements as the cells are linked with welded straps and are also welded to the metal strips which form the connectors.

I was only considering changing to a Lithium DeWalt battery as I have the correct charger for that whereas if I were to fit Lithium cells in the existing case I would presumably still need a suitable Makita style charger.

I did find these on Amazon. They're Ni-MH which looks to be not as good as Lithium but can be charged with the NiCad charger.

https://www.amazon.co.uk/VANTTECH-192828-1-192829-9-193061-8-193102-0/dp/B07WCN2NN2/ref=pd_rhf_ee_p_img_2?_encoding=UTF8&psc=1&refRID=S3PA7NZX 35V1D57JJG5J

These do have some negative feedback so I'm not sure it's worth spending £30 for a single battery which may not actually be that good.

John.


Bluemoon - 31/3/21 at 08:54 AM

I have re-celled Ni-cad packs before. used these guys, cheap cells seem to work well and also already tagged so you can solder them together..

https://www.batteriesplus.co.uk/acatalog/1.2V_NiCd_Sub_C_Rechargeable_Tagged_Batteries.html