Cordless drill replacement pack

[MonkeyThink]

Having scored a bunch of high drain Sony VTC4's from Dyson packs I'm thinking of using them to resurrect my NiCd powered 14.4v drill.

Just done and experiment with a lashed together4s pack and all works fine. At 2,000mAh it's already better than the packs it came with (12s 1.2v, 1,200mAh NiCd cells! = 14.4v / 1,200mAh - Yuk!).

Just need a 4s BMS - Something cheap from China I'm thinking.

For charging I'd like to use a cheap wall-wart or perhaps an old laptop power supply. I have one with 20v 3.25A output.Am I right that I need to limit the current that is drawn? What's the best option here?

Thanks
Adam

 

[Overmind]

If you use a BMS, it's enough for the charging process. As for the discharge part, some use the BMS attached to the battery, some to the charger. I prefer putting it in the charger because many low quality BMSs will cause problems if you discharge through them. So I let the battery be as clean as possible and allow the drill to fully utilize it's power.

 

[MAGPIES2020]

Having scored a bunch of high drain Sony VTC4's from Dyson packs I'm thinking of using them to resurrect my NiCd powered 14.4v drill.

Just done and experiment with a lashed together4s pack and all works fine. At 2,000mAh it's already better than the packs it came with (12s 1.2v, 1,200mAh NiCd cells! = 14.4v / 1,200mAh - Yuk!).

Just need a 4s BMS - Something cheap from China I'm thinking.

For charging I'd like to use a cheap wall-wart or perhaps an old laptop power supply. I have one with 20v 3.25A output.Am I right that I need to limit the current that is drawn? What's the best option here?

Thanks
Adam

I also have vtc4 from dyson battery pack to do similar to what you are doing. repack failed drill packs. i find it hard to get the last 2 batteries out of the dyson plastic case. do you have any suggestions how to remove the glue holding the last 2 batteries in the plastic case, tks