I just returned from a trip to the east coast and back. I had installed a BrakeBuddy charger and when I stopped after my first days drive the battery was dead. Checked fuse and everything was as it should be. Apparrenty the thing is a waste of money. I took it out and simply extended the power line from the MH direct to the jump point under the hood. Line is putting out approx 14 volts with MH engine running. After driving the next day the car was charged and all was good. No problem rest of trip. Is there any downside to running this way as opposed to having a charge control device installed?
What's the rating of the BrakeBuddy.? My guess it's 1 - 2 Amps (trickle charger = $17). That's likely not enough to keep the C-Max battery charged when in N. That's only 12 -24 Watts. The active modules likely use more than that. The Toad Charge = $80 appears to be a 10 Amp maximum output which would be able to keep up with about a 120 Watt load. Most times you get what you pay for.
By directly paralleling the C-Max and MH batteries, your MH voltage regulator is now trying to regulate two batteries as one AND the C-Max battery can also supply load to the MH. This is why the Toad Charge has this feature:
"The TOAD-CHARGE™ kit consists of several components: The Charge Controller installs in the towed vehicle's engine compartment - It monitors the charging current and prevents reverse current flow when the motorhome engine is started."
So, the issue is that you will have different voltage drops across the batteries when charging because of the different wire lengths (resistance) involved and the batteries are not the same size which they should be using two wired in parallel on one charge controller.
Edited by Plus 3 Golfer, 23 October 2017 - 10:08 PM.