Best Charging Option for 12S LiIon (A123?)

[sylathnie]

I'm attempting to put my new Ele II to use and the first thing I need is a good charger. I would like to charge/balance all 12 cells in series but I may be willing to break the pack up as long as I can balance the whole pack in some way. I do not have a large strong DC power supply so the cost of that will need to be figured into the comparison.
Upgradable would be good but if something is programmable enough I'm not sure what an upgrade would get me that I couldn't program.

So far I've come up with:
EOS1210i with 2 balancers
E-Station BC-6 with 2x PB-6

Anything else I should be looking at? I'm not worried about spending alot of money. I don't intend on buying another charger so this needs to keep me happy for a while.
Thanks!

 

[alfreddajero]

This is the highest that i have seen a charger go....you might have to break the cells in half.

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXTPG0&P=7

 

[JimmyM]

The Schulze next 7.36-12 will charge/balance 12 cells.
A bit pricey.

 

[LuxLuthor]

I think top Schultze is your only single option.

I have done the EOS1210i with 2 x LBA-10 balancers networked, and it works fine....but you need to address getting the balance tap leads attached & installed (crimped) into the two 7-pin JST connectors.

 

[sylathnie]

Hrm that is a serious chunk of cash for the Schulze. Any downsides to using the BC-6 with the networked balancers? (Charge the cells 6 at a time and then balance them all together.)
The only downside I see is that all cells will be balanced to the lowest cell rather than to full. But I think I can live without that extra tiny bit of capacity.

Any recommendations for a AC-DC power supply? I'm leaning towards just buying a car battery and a trickle charger and tucking it under my work bench so I have all the 12V I need whenever I need it.

 

[LuxLuthor]

I consider the BC-6 (& the Tenergy/DN for 4s Li-Ion) to be at the bottom end of acceptable hobby chargers. It can output up to 5 Amps, but cannot be networked to charge 12s. I suppose you could play around with charges to get them all balanced close.

The high Schultze price was the main reason I bought the single Hyperion 1210i with two balancers that network together. If you are using the BC-6, it has a built in AC plug so unless you are out at the park doing RC flying, you don't need a 12V supply.

If you go with the Hyperion 1210i & two balancers....and ever think you will want to do 20s+ NiMH (I needed it for the 24s Elite NiMH SubC pack in Larry 14K spotlight), then you are better getting a 20A 13.8V PS. My 10Amp was inadequate.

 

[HarryN]

I just went through the whole charger selection process myself. I picked up a power supply from nitrorcthunder.com (web site didn't work this morning for some reason, but the ps is nice) 30 amps for $ 60.

A lot of r/c people use their car batteries to run the chargers, esp in the field, so that is a viable option.

12S Li based cells takes a serious charger and I think there is only one other charger I have ever seen that would do that other than the Schultze, and it cost even more.

I would be very careful about balancing a pack that large. There are a lot of internet forum discussions about the actual nature of how a Li based cell charges, and it is not so simple as just balancing out the voltages when you are finished topping them off, you really are trying to balance the power in each cell to the others as well. Charging is a non - linear process.

My simplistic understanding of this means that in order to really balance a pack, it needs to be balanced at least once at the beginning of charging, again in the middle, and then again at the end (at a minimum) Less than this risks creating an unbalanced pack during the discharge under high load conditions, as well as overcharging cells in the pack - sometimes substantially.

I will admit that not everyone does this, but very few also run a pack that large.

The Schultze balances regularly during the charge cycle, so this optimizes charge balance throughout the pack. The balancing is "built in" to the charger from a hardware, software, and charging per cell aspect. This makes the charger very appealing from a technical and wire nest perspective.

If you are going to run only A123s and not LiIons or LiPos, the balancing requirements are somewhat less, but not zero.

My needs topped out at 15 cell NiMH and 24 volt Pb acid, which ultimately pushed me to the Triton 2, but the Schultze was my first choice (other than price) and the Hyperion was in 3rd only because of its 12 V Pb acid max.

 

[jabe1]

What's a good single or dual cell charger for these batts?

 

[HarryN]

As long as you are charging only 1 cell at a time, or maybe multiple ones in parallel, the process is sort of self balancing. Charging 2 in series starts to make balancing important. There are some very knowledgeable people that claim a pack made from A123s will largely stay in balance after 4 - 5 (balanced) charge cycles. This does not appear to be true of LiPos and Li Ions.

This is where I got the most info from on charger selection that I have ever seen. Just click on the charger button, and it will bring up an amazingly comprehensive list of chargers and specs. Almost too many to pick from, but at least the info is in one place.

http://progressiverc.com/Research.html

For me, the final charger selection was driven by two battery powered tools that I have (the chargers had failed) Think about your charging needs in a comprehensive way before buying one, not just your flashlight needs.

 

[jabe1]

Thanks for the info...thinking about a 1 m1 cell powered light, maybe a cree MR-E.

 

[sylathnie]

I went ahead with a Hyperion EOS1210i. I also bought a nice lab quality 0-50V 0-20A power supply to use for the charger as well as other experiments. I think the Hyperion will easy meet my needs for now and the future.

I just couldn't justify the cost of the Schulze. $600+ was way to much for what I was looking for.

 

[LuxLuthor]

I guarantee the Hyperion 1210i with two LBA-10 6s balancers networked does an excellent job at balancing 12s A123, & Emoli cells. I have done it many times, and it continuously balances throughout the charge process.

You can also just connect cells to balancer(s) alone with no charger, and it gets them matched within 0.02V (i.e. 4.18V to 4.20V).