Makita 18V Battery Replacement Board

[@MichelleWardley]

What was the fluid you used. To undo the screw before chopping the wire

[@ThriftyToolShed]

Are you asking about the Rosin Flux?

[@MichelleWardley]

@@ThriftyToolShed was it in a thin white 🍼

[@joesoika2628]

Good video leaned something today! Thanks

[@marshall7201]

Good video! I have 3 batteries that are reading good voltage but won't charge. I have not opened them up yet.

[@julianhoyland]

Great video! What voltage does the new PCB cut the power at please? I'd like to fix my battery but am worried about damaging the cells with a cheap board.

[@jimlee5626]

Great information. Tearing into mine soon. Thanks!!!

[@ronaldwoofer5024]

do these boards have internal diode to allow 2 packs to be connected in series 36v ?

[@ThriftyToolShed]

No diode that I remember. They could be in series for 36-40V. Just have to monitor the voltage as to not allow them to drop below cut off voltage with a Low voltage cut out board or some other monitor so as not to over discharge. I have a video of a couple of low cut out boards that are fairly cheap and work pretty well.

[@vje24]

Hi,great video 👍 the pack will after few charging degrade,and fuse inside 18650 will blow ,better use controller with balance charging,that with BMC in name....keep up with good videos...

[@leonvanengelen1824]

got some good experience with the chinese boards. they are really cheap and the ones i use do actually balance charge. BUT! i like the makita boards better and would kill to learn a way for un-bricking them (have a bl1840 that is fused at 90a, so should really deliver the beans!!!). i think there should be a way of resetting the micro controller or something that would make mine work again. they are usually in a real good shape because they are sealed and not exposed to oils and other liquids, but useless as they are. if anyone has any ideas on wich leg of the microcontroller you need to connect to what that would make my week atleast.

[@leonvanengelen1824]

and by the way, if i may suggest. makita usually uses the sony murata vtc series cells, and where i live you can get those for about 2 dollar a pop for a vtc4a, wich is one of the highest drain cells. not only on the short 30a, but also sustained periods. they are aparently salvaged out of new packs with spot welding defects, so never used. some of the tools makita produces are almost a dead short and i would recommend using a capable cell to keep it alive for many charges to come

[@ThriftyToolShed]

Yes, the Makita board is better for sure when working. Several manufacturers do this including Dyson. I have pack repair videos that show some packs with a microcontroller reset, but this need more than a reset it seems. These may need to be reprogrammed?

[@leonvanengelen1824]

@@ThriftyToolShed im not sure. i dont know enough about micro controllers. these battery's keep track of lots of things, like the amount of charge cycles and the percentage of its life it has been overloaded(whatever thay may be exactly). mine has two mc on board, and thats even one without the indicator lights. i am afraid you might be right that it would need reprogramming, but thanks for your time and thoughts

[@GridRewired]

Thanks for this comment. I came here looking for an answer to why my rebuilt pack can be charged by a non Makita charger and show a full 20V and light up all the lights on the tools but not deliver any power. I could only guess the board was causing this issue. This quick thread confirms that the board must have to be changed in order to get the pack working again.

[@TauCu]

jesus christ. how come name brand companies can't seem to figure out how to implement cell balancing on their products. perhaps so you go through batteries quickly.

[@leonvanengelen1824]

fortunately most makita do have cell balancing. even their charger is a balance charger. if you look into the track the batteries slide on, the positive is not even present. the bigger packs usually have balancing. the unbalanced packs also seem to last longer than i would expect. got one from a friend in february this year and it has worked for years and years. as expected the voltage on those cells were everywhere, and it ultimately failed bc of a 0v cell(protection cap popped)

[@トックー-k6z]

基盤が昔のものですね