Better charging for your 18650s...

I ordered a 4-pack of Tenergy 18650 2600mAh batteries and also the charger. As I already have a good charger (Hyperion 1210i/LBA10), I wanted to use the Tenergy charger as a battery holder for this. So, if you already have a good charger/balancer, here is a way to use it for 18650/RCR123A batteries.

First, open the Tenergy charger. You will see that this charger is very simple:


Next, modify it so the batteries are in serial and connect your balancer:


1. Cut the connectors so you only got 1 to 1 connection to the battery poles
2. connect a positive 18650 connector and a positive CR123 connector
3. connect the other negative 18650 connector and the other negative CR123 connector
4. connect the remaining positive and negative 18650 connectors
5. connect the remaining positive and negative CR123 connectors
6. connect point 4 and 5
7. connect balancer to 2 (+), 3 (-) and 6
8. connect power to 2 (+) and 3 (-)
9. You're done..

Happy charging:

Yep, that will work if you happen to have a Hyperion laying around

You really could have just wired them parallel to each other and skipped the balanace board. However, you would want them to be the same capacity batteries and approx the same state of charge, probably within .2V or so. Ok, maybe .3 would be fine.

DSD charger, hah, I have one of those, promptly gutted it for use as a battery holder.

I have an Hyperion 0720i balancing charger which I used for my RC Helicopter hobby and love it.

For more portability and ease of charging 18650 batteries though I kept searching all the flashlight, laser, etc forums and finally found a cheap charger that actually charges Li-Ion batteries properly without overcharging anytime during the charge. It has 2 independent channels (SheKor Intelligent Charger for 18650/17670/18500/17500/14500/16340). It seems to be a proper CV/CC charger based on all the reading I have found on it(without overcharging). It actually slightly undercharges to around 4.14v which means your batteries will last longer (you won't notice that last around 4% not being charged.

All the other cheap chargers overcharged or didn't do CC/CV properly during the charge.

About $10 with free shipping. It might take a few weeks to get it though because it comes on a slowboat. You can order it from the US I think somewhere but it is about $5 more. I ordered a few to sell with lasers.

http://kaidomain.com/ProductDetails.aspx?ProductId=9650

I tested the 3 I bought and they work VERY well. Highly recommended. The only downsides from kaidomain are slow shipping from abroad and the boxes tend to get a little smooshed from the overseas shipping. All 3 chargers work though so the box damage didn't affect the chargers.