On 25/01/13 16:52, Ben Jarrett wrote:
Now I get low voltage alerts from my BMS and from the Soliton for very = moderate acceleration and at much lower speeds (like 35 mph).
Are your cells cold?
What I would like to do is put my jeep on a full vehicle dyno and test = the voltage drop at various places to see if something else is awry.
That would work but, depending on where your battery boxes are, it might still be difficult.
I would start with something smaller first. Make something like this: http://carrott.org/blog/archives/150-Load-Tester.html If you already have a heater in your car, you can use that.
You can also do a capacity test with a simple domestic heater or a kettle but be very sure that any switches or thermostats are disabled -- they are likely to catch fire if they try to turn off the heater on DC.
If you can't work out what is going on at low-ish currents then a chassis dyno is probably the best next step and you'll have had practice before going on the pay by the hour dyno.
Did you do anything to prepare and protect the connections to your cells? If you don't exclude air with something like noalox then they will deteriorate, especially if exposed to the weather. How long have they been in the car? If the cell terminals are corroding, you'll have to clean them with fine sandpaper.
I have a BMS which gives me individual cell voltages so I can do things like this: http://carrott.org/blog/archives/145-33.4Ah.html
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