Using 18650 laptop batteries for my drills - RC-Monster Forums

snellemin · **Using 18650 laptop batteries for my drills -** 12.17.2010, 06:40 PM

Some of you know that I've been using laptop batteries for a number of things. From Flashlights, RC, Power wheels, Transmitter, Receiver, and rumors of breast pumps.

Well I have a cheapo chinese drill with even cheapo nicads. Also have a 12 yr old Makita drill with bad batteries. So instead of buying some overpriced nicad pack to replace them, I opted to use the 18650 laptop batteries. I have a choice of 3s or 4s on the Makita, which was originally 9.6V. Son of a monkey is one powerfull setup now. The chinese drill got a 3s2p pack, for really really long run time when I polish metal pieces.

sikeston34m · 12.17.2010, 06:48 PM

Very Nice Snell.

I've been playing around with several varieties of the 18650's also.

I see some samsung 2600mah cells in your picture.

The only thing you have to be careful about is not to exceed their max discharge ability. Most regular 18650's will top out at around a 4 amp draw.

If you take a look into the cordless tools of today, you will find several high discharge varieties of the 18650. Makita uses one that can be discharged up to a 25 amp draw.

Here's a link to show you some of who's using what when it comes to power tools. I hope you enjoy it.

http://dewaltownersgroup.com/index.php/topic,204.0.html

snellemin · 12.17.2010, 07:02 PM

Nice link man. Thanks.

The ones I use are 5A cont and 45A peak. That is with the datalogger. I wouldn't be playing with the cells if I didn't get the packs for free.

pinkpanda3310 · 12.18.2010, 01:52 AM

I've been to tool repair shops and asked for redundant battery packs before. Too many nicads, lots of l-ion and I was really lucky one day and got a heap of A123's. I didn't take any nicad's but it was all free

Just had to be careful not to mix the batteries as they obviously had different cycle life.

sikeston34m · 12.18.2010, 10:37 AM

Something I'm playing around with here lately is:

Leave the pcb inline to protect the cells on the pack, then use a dc to dc converter to adjust the output voltage to match whatever is being powered.

Small dc to dc converters are pretty cheap. I just bought a 3 amp unit off Ebay.

It's specs are:

Input Voltage: 3-30VDC.
Output voltage: 1.3-18VDC.
Max output current: 3A.
Built in LM2596S-ADJ.
Compact size. (about 1 1/2" x 1 1/2")

For lighting, this would be a great thing.

It has a pretty wide input range. (as low as 1s or as high as 7s)

I'm thinking it could run a large amount of Led lighting in the event of a power outage.

lincpimp · 12.18.2010, 09:05 PM

Quote:

Originally Posted by snellemin

Nice link man. Thanks.

The ones I use are 5A cont and 45A peak. That is with the datalogger. I wouldn't be playing with the cells if I didn't get the packs for free.

That is interesting, have a link to these cells? I would like to make a few better packs for my milwaukee drill, 28v model.

I use 18650 cells for almost all of my flashlights. Get them out of laptops, 2600mah cells, sony, IIRC.

pinkpanda3310 · 12.18.2010, 09:53 PM

Milwaukee uses batteries similar to A123's don't they? Or at least they are a similar size? You might be able to reuse the same battery pack by replacing just the cells.

Or maybe not it's been a while since I've looked at stuff like that

sikeston34m · 12.18.2010, 09:59 PM

What's the largest 18650 pack you've built?

Did you know the Tesla Roadster uses a pack built from 6800pcs of 18650?

The pack weighs 992 pounds and the car will 0 to 60 in less than 4 seconds.

It also has a 200 mile range.

Just some interesting facts I found. Thought you might find it interesting.

lincpimp · 12.18.2010, 10:08 PM

Quote:

Originally Posted by pinkpanda3310

Milwaukee uses batteries similar to A123's don't they? Or at least they are a similar size? You might be able to reuse the same battery pack by replacing just the cells.

Or maybe not it's been a while since I've looked at stuff like that

They use an emoli cell, it is lipo, so 3.7 nominal. Might be the same dimension as a 18650 cell. I currently have it wired as a 3s and a 4s for balance taps so I can use a hobby charger to get the job done. Might just buy a real battery for 100 bucks or so... That way I can use the stock charger...

pinkpanda3310 · 12.19.2010, 08:55 AM

Emoli rings a bell. I didn't know there are lipo

snellemin · 12.19.2010, 04:10 PM

The HP battery packs that I get, have LG and Samsung cells. I charge them like lipos without issues. The older packs have Sony cells in them.