Anybody done a cordless drill lipo conversion yet?

JW if anybody done a lipo cordless drill battery conversion yet? It’s 6 18650s I think in serial, looks very dangerous lol but anyways now I wanna know how to add load balancing?

I did it, sort of, just plugged in an 4s liPo battery for RC and exposed balance connectors so it can be balance charged.

but it’s not a proper way to do it, here follows my experience/observations/conclusions:

the main problem is that you need a protective circuit/PCB with high discharge current capabilities, because cordless drill requires a big big current, 10s of Amperes in peak, I was not able to measure the peak current. If the circuit can’t deliver that, it will just shut down when you need the current/momentum. Protective circuits that can deliver that current are expensive. Using the cordless drill without that circuit could be dangerous (cell reversal).

alternative which I was looking at, is to build in a low-voltage buzzer, there are cheap ones at hobbyking. But still isn’t a proper solution.

There are a lot of people out there doing some VERY dangerous things with these cells.
This guy is using 6 - ICR’s in an application that demands IMR’s. He doesn’t know the difference. Also he has wired 6 of them in series when 5 in series is what will give approximately the equivalent voltage. That actually may be saving him, as he is using his stock NiCad charger to charge this pack. There is no balancing of the cells. That extra cell may be preventing an over charge in the near future, but that will change.
Although everything he has done would seem reasonable and proper to a novice, IT IS NOT. This can be very dangerous and I’m afraid disaster awaits him. He may have gotten away with it so far, but it will come back and bite him.

I am thankful you posted this, because at the end of the video, YouTube points to similar videos and it pointed to this one that I came across once and could not find again.

If you REALLY want to see something stupid, watch what THIS guys does!

Wow has Old Lumens and Scaru seen this video? Tempting now for me to open up very dead lithium ion battery! jk.

Priceless!

5:09… “lemme just get a paper towel and get this blood off me here…”

I do wish that we could educate people a little better about the dangers of lithium ion batteries.

Impressive that these people survive into adulthood and even without maiming themselves….

Correct me if I’m wrong, but this could be the proper solution (for 6s) if one fits inside battery pack box. This circuit controls charging, discharging, balancing. Also controls temperature, over current, short circuit and has working current between 60A and 80A which should be enough for any 24V power tool. You only need correct power supply, I think that any supply with sufficient Voltage will do. Maybe You could use old charger that You got with power drill - this I’m not sure but I think You could. If this works, this is the cheapest complete solution for converting from NiCd to Lipo. I’ll definitely try.

http://www.batterybms.com/222v6spcmbmspcbforli-ionli-polymerbatterypack/PCB-D131.html

Where did you see the price for it ?

Contacted factory, minimal order is 2 PCS. Price for 3s-35A was around $25 (shipping included).

thats $25/pc or /2pc ?

1 circuit - $25, 2 circuits - $50 (for 3s - 35A working current). Would be nice if someone could help with charger. If this circuit works as stated, is it possible to use old NiCd charger.

If you want to trust that device. Designed and built by some random chinese company. Chinese companies are known to often use the cheapest components they can find, use counterfeit components, secretly substitute components and just straight up create hazardous circuits.

Yes, most things are “made in china” but they are designed by local or major international companies (within the reach of local laws and lawsuits), designs that have to actually follow safety regulations. Manufactured only by major chinese manufacturers who have million dollar contacts at stake (and still require tight oversight).

a lot depends on the PCB. Does it itself do balance charging and you feed it voltage, or you need an additional charger/balancer. Looking at the PCB specs, it might be all you need, btu not sure.

When you account for all expenses and time, is it worth it?

It has balancing port, just like my hobby charger. New battery (NiCd) for my 12V Makita power drill costs around $100. This should cost about half that (batteries included).

This isn’t a charger. All it does is bleed power off of the stronger cells. Over time, the wear on those cells will make them equal to the weaker cells so they all discharge at the rate, thus not killing the weakest cells from over discharge.

It’s best to match the cells first and discard the weakest ones or you could just end up conditioning good cells to equal the bad ones. Use weak and strong cells in separate packs for series. Parallel sets stay balanced so mixing weak and strong is ok but the average capacity for each set should match the other sets of parallel cells in the whole series.

Connecting a car battery to an 18650 he says “I feel the battery getting a little bit warm so I’m going to stop” lol … Kaboom would have been my guess … amazing … “plus to plus and minus to minus” and the DMM is reading negative … “now I’ll wipe some more blood off here, sharp knife, be careful” … Darwin award candidate anyone??

You can count the number of times he’s done this by his scars.

These guys are wild—- I wonder if the drill pack guy realises when you strap batteries together and flip them they can short out between the wrappers— A hobby charger might save his life or even his family

Ok found the dimensions of it. It’s a tad hard of a squeeze but I’m gonna use this, no BMS circuitry needed since i have a hobby charger.

The demsions are linked here: http://www.homedepot.com/p/BLACK-DECKER-18-Volt-Ni-Cad-Slide-Pack-Battery-HPB18-OPE-1/100662349

5.75” x 2.88” x 2.63”

This guy seems to have built a good battery pack