Cooling a Gen II pack while charging?

A portable AC unit blowing cold air at module clamped by aluminium electrical style heat sinks would keep the nice and cool. Several modules clamped together with aluminium plates between them "larger than the modules" with cold air blowing on them would allow for charging more than one module at a time.

John (Britprius)

 

I would just pick up a small vent fan and put it in the hatch.

JeffD

 

Are you concerned about the cells while you have them on the bench in your shop, or later after they are in a car?

 

It would be better to remove the pack and work on it where you can maintain an air conditioned environment (use forced air over the packs while charging, not too hard to rig something up on the bench). It also helps to lower the charge current to keep heat down especially if you will be exercising them above 7000mAh. Finally make sure to charge no more than every other cell at a time beacuse the ones nearby will act as heat sinks to dissipate any built up heat relatively quickly.

 

Jessica,
Welcome to PC.

Concerning recharging lithium batteries on the bench and elevated temps is a major concern of mine.

While L don't have Li bats in my current Prius, I do run Li bats on my E Bike. During charge up, I put a refreezabe blue ice pack on the charger and Li packs. No problem with overheating. On the Prius, I make sure the bat vent, ducting, & fan are clean. I installed a replaceable piece of filter paper behind the bat vent. In warmer weather , I run the AC constantly. This does help the bat pack keep cool.

DBCassidy

 

Jessica, it sounds like youre doing it right (charging every other module) but I would focus on two things to help your situation. First I would try to build a bench setup to duct an air conditioner through the prius battery while you are cycling them (no need to remove them from the HV pack). Second I would try experimenting by lowering the capacity to 7000 mAh and lower the charge current to 2A then slowly raise the capacity by 100 mAh each cycle until you reach 7500 mAh. This should allow you to hone your process for best results (if capacity drops you will have gone beyond optimal capacity for cycling). Please post your findings so we may all benefit later too.

 

Wouldn't using the Prius fan itself work for this purpose? Seems like it would, but I am still learning about all the cool charge/discharge toys available for the Prius ;-)

 

Jeff I think you showed in the grid charging thread it´s pretty easy to set something up.

Grid Charge HV Battery to Balance? | PriusChat

If someone was going to do commercial rebuilding of packs I would probably adapt the system from the prius into some type of bench jig. Then you would want to help the heat transfer process by running cooled air (air conditioning) especially if this was being done in a warm climate. If central air conditioning was available it would be fairly easy to branch off a section and run the insulated duct through the bench jig. Otherwise you could certainly design something using a portable air conditioner but it would be less efficient than using central air.