Hi people!
i have a Makita drill and the battery is broken.
Original battery is ni-mh 24v and i want to put li-ion batterys inside a pak
When i sold 6 18650 batteryes together i think that it is enough voltage for this drill.
Problem is that my charger starts to charge and after fev seconds stop and blink like the batery is broken. 
the charger is made for li-ion and for ni-mh batteryes…
It will be the circuit or lack of in the battery pack.
Where in the world do you live?
i will try to put some pictures of battery… 
on the li-ion batteryes there is a third wire and i don’t know where it goes on the batteries plus and minus is ok and battery is working when i put it on the drill…
The extra wire on li-ion power tool packs is often to a temperature sensor (NTC thermsistor).
By the way BLF is going offline for upgrade in like 3 minutes
there is a separated jack with two sensors on it and i leave it conected as it was… just to find out how to put some pictures here and you will see…
where i have to put TH wire on batteries??
Is that a picture of the ni-mh pack or a li-ion?
The sensors will be attached to the side of the batteries.
What is the yellow block? Are there any pins / connectors in the yellow block which make contact with the charger?
This was ni-mh pack but i took out old cells and put new li-ion inside…
Yelow block is conected with two heat sensors…
My question is where i have to connect TH pin
Where was the TH pin connected before?
What protection circuit were you planning of using? From what I know it will be hard to find one that can handle currents needed by the drill. I would advise against using it without one, for safety concerns. IMO It would need balanced charging, temp protection, per cell voltage monitoring.
Th pin was not conected….
Yes it will be good to have some protection for batteries but i don’t have it
My onli problem is that charger start to charge and after few seconds stop chargeing an blink like the battery is broken
The charger may be doing a sanity check, and since it is not finding the balance charger circuit, giving up.
How can i make him find his balance?
Best would be to scrounge a dead or broken LiIon pack and configure yours with parts from it. I’d be quite worried about charging problems and reverse charging of a cell with it done any other way.
Phil
I can help with this. My 18v 3.0ah pack quit. They have a circuit that protects the pack from accidents. If it gets tripped more than 3 times, it bricks the pack, or rather the circuit on the pack for charging purposes. However, the pack still works in the tool. I charge this pack with an Accucell6. I connect the main leads on the leads I extended (+ and -). I finally killed the pack after 2 years, it was made of 2 discarded packs for a paint sprayer. I used it in my hammer drill to make several holes through concrete. Now it takes forever to balance charge and it’s capacity is diminished.
If you give up on hacking your pack, I just posted a question about non-oem battery replacement packs. Though I am not sure you can get a li-ion pack for a nicad drill.