[ev59rag]

Here is one...

This is the one Im planning on using (dump controller) on my ev. Already using it for my solar panels. Works great.
ghurd - Hurd Solar Renewable Energy | Dump Controllers


Another similar setup but designed in tune for EV users like us.
Volt Blocher


And here for monitoring your batteries.
http://www.evconvert.com/article/led...monitor-part-2


Hope this helps.