Interesting variation on my basic grid charger concept:
http://99mpg.com/Data/resources/down...balancer_2.pdf
dual current version:
http://99mpg.com/Data/resources/down...d_charger1.pdf
Universal microcontroller version which I will be selling in the next month or so.
http://99mpg.com/Data/resources/down...gersystem1.pdf
The only disadvantage I can see to your version is that you cannot set a maximum voltage after which the CC becomes a declining current when the battery reaches full. From my experience with the prius cells, they can overheat and vent even at the low 350ma, if they are fully charged, and the current is maintained so I hope you are powering up the blower when you are charging, or that you have a timer on the charger.
I used 3 or 4 fixed 48V supplies each of which could be set over a 10% range. The single 350ma CC supply max voltage is 48V, so if you are charging an insight pack, which will usually read about 168V when full, you can set the no load voltage of the combined power supplies to say 165V, by adjusting one or more of the fixed voltage supplies, and when the pack reaches that max voltage, the current will start to ramp down towards zero as the pack voltage rises above that setting.
The universal charger will be able to charge anything from a single 6 cell
prius or Honda subpack at 7.2V nominal , to a second gen prius pack.
operational description is here.
http://99mpg.com/Projectcars/buildingahybridcar/
Custom internal harnesses will be available for the first and second generation Insight, All of the Civics, and the second gen Prius.
The civic amd prius blowers require a PWM speed control, which will be a small microcontroller circuit that will switch blower control from the stock controller to the charger controller when the charger is powered up.
Temperature probes will measure inlet air temperature and the outlet ait temperature, and can be set to shut down the charger is the differential gets too high.
On the first generation insight, and civics where the pack has a positive temperature coefficient thermal strip running next to each cell, the charger will also watch for the combined resistance to get over an adjustable threshold where it will shut down.
So far it looks like as much as 80-90% of batteries that are experiencing recalibrations or setting IMA codes respond to the rebalancing well and the problems stop. Some for several months, others for a shorter time.
I was told that the Toyota patent on the battery management system mentions an occasional balancing as a requirement for long life of the pack.
It seems that honda missed the mark by not providing a mechanism to accomplish that.