Easy Charging (and balancing) Method!!

bossiamnot

100 µW
Joined
Nov 21, 2014
Messages
8
Why had I never thought of this before??

Just found this on the web. http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=26136

To charge a battery, all that'd be needed is a charger like this: http://www.all-battery.com/Li-Ion_and_Li-Po6Cells22.2V2ABatteryCharger-01038.aspx

You could even use a JR TX type connecter for charger and battery (y off for battery) and it'd be perfect. No more juggling of wires for a recharge!

This is going to make things wayy easier for me...... 8)
 
It is slow and will get super hot. It may also drain your battery if you leave it connected for long periods of time.
 
That is kinda cute.

Looks like it might be worth having around for periodic rebalancing

Has anyone tried it to see if it works at all ? It would be a lot quicker for me than pulling the battery pack and individually balancing charging the packs.
 
I have one of those laptop style power supply that can give 8amps (yours only 2amps) , I have it plugged into a proper rc charger.
If I set the charger to draw more then even 5amps the laptop style power supply gets super hot.
Even with the setup I have it still takes at least 12hours to charge a 11ah battery pack of mine.
I only use it when time is not an issue.
 
I am using exactly that turnigy dlux just as fuel gauge and on board cell checker and it works fine. But I have a switch to disconnect it from the battery and still use a full rc balance charger for charging. This thing will not actually balance but drain all other cells to the same voltage of the lowest one, which takes ages at a slow rate, creates heat and ofc drains your battery. So: Fuel gauge and on board checker yes, on board balancer not worth the trouble.

Better get a plug with enough pins to solder your power and balancing connectors to, so you get a one plug solution, and use a regular rc charger. I balance charge my 5.8ah 6s setup through a dsub plug with 5 amps in little over 5 hours.
 
OK, it works ....

Balancer.jpg

So I bought one to solve a problem that I had.

I run an 11s LIPO (2 packs, 6s pack and a 5s pack 5000mAh) in parallel with an 11s (LiMn) Trek Ride+ (Bionx) battery. It gives me a total capacity of about 10Ah and a nominal 41V system. I ride it down to 20% or so and just bulk charge the whole mess with the Bionx charger. After 30 rides or so, the LIPO packs develop small imbalances -- like a range of 4.11 - 4.16 volts at full charge.

Since I don't really know how much imbalance is "safe", I generally pull them apart and balance charge about once per month, but that takes a lot of time and means breaking and re-making connections I would really prefer never to touch.

So when I saw this "balancer" I thought "what the hell, this could solve that problem". I bought one.

So now I just hook it to the balance lead of each LIPO pack and in about an hour, the pack is nicely balanced within 0.01V and the balancer goes "off". The balancer gets slightly warm but not hot and seems to work quite nicely for small imbalances. I don't leave it hooked up and I don't know what the current draw really is in the "off" state. I do know that I have left it hooked up for up to 4 hours without any drop in voltage (<0.01 V).

So for me this is a nice addition to my set of tools.

An update (October 2015) -- did find a down side. I hooked this up to balance out a couple of 0.03V differences in my 5s 5Ah LIPO pack. I checked the progress after about 30 minutes and it was half done. Then I COMPLETELY forgot about it and left it hooked up for about 48 hours. It apparently finished the balancing and entered "sleep" mode, probably within an hour of when I last checked it. However, over the next 47 hours it apparently continued to draw current and when I remembered it, it had drained the first three cells somewhat. It should have balanced out at 4.15V across the board and gone to sleep, but after 48 hours, it left me with 3.90, 3.90, 3.90, 4.15, 4.15. So the current draw in sleep mode is NOT zero, in fact, it seems to be relatively large. Since the three low cells are the ones that originally were high, I think that perhaps there is no sleep mode, and it just continues to draw down the same cells it was drawing down before it reached "balance".

In any case, the moral of the story is don't leave it unattended for 48 hours.
 
Yeah it should work great as long as your packs generally stay pretty balanced. I've also had the idea of using a balance board such as the one linked below

http://www.bestechpower.com/balanceboard/JH-D131A.html

during charging to bleed down the cells that reach 4.2V first. Note that the linked board only balances at about 0.2A so it would only work for packs that stay sort of balanced.

The danger of charging this way would be that one cell gets to 4.2V way before the other ones and your charger just keeps dumping current in without the balancer telling it to slow down since the balancer is not connected to the charger.
 
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