Wiring '02 T-Blazr for battery charge

[rjjastone]

So I finally got the Roadmaster Base Plates installed on our '02 T-Blazer, and now I'm reaching out to all you experienced iRV2 electrical experts for opinions as to the best practices for charging a Toad battery using a 6-way trailer connector on our '99 Holiday Rambler DP. I'm planning to use the connector's +12VDC center connection and the ground connection to supply charging voltage to the Toad battery, and the circuit will only be "hot" when the RV's ignition switch is in the "Run" position. It'll be primarily supplying power for the Roadmaster BrakePro (10.8A max.), along with the brake lights. Beyond that, the dingy battery should only experience it's normal parasitic current draw, with the ignition switch remaining in the "OFF position during towing. Running lights and turn signals will be illuminated by the RV circuits through the 6-way connector.

I'm planning to use a 15A in-line fuse to protect the +12VDC wire at the Toad battery in the event of a dead short in the circuit, but other than that, what else is necessary, or desired?

1. Isolation Diode?
2. Isolation Relay?
3. Would I be better advised to install a battery charger such as the RVi charger to regulate the charge current, as opposed to just supplying unregulated +12VDC during the time the RV is running?

Thanks in advance for your suggestions.

[Winemaker2]

I simply installed a 10 A fuse in the + wire to the batty on my '14 CRV and so far no issues.
I have unplugged the 7/6 wire cord at nite in a pull thru but that's probably ultra conservative.
I inquired at RVi and asked if their charge line offered any specific advantages and they replied that if I was confortable installing wiring & fuses I should be fine.
I would put the fuse close to the toad batty+ to minimize chace of short causing fire... I did see a recent post that used a resetting breaker that allowed a fire that totalled the toad...I'll replace fuses instead.

[Pigman1]

I'm not sure about the 10A fuse if your toad battery is low. I use a 20A on a 10ga wire and put it as close to the toad battery post as you can get it. I'm assuming your +12vdc in the coach is fused before the rear plug.

Forget about the diodes and the relays unless you have an insurmountable urge to spend money for something which will give you lesser performance than the straight through wire. Companies have great sales forces selling something you don't need and mostly do it by appealing to the undefined fears of the uninformed. I've been using the straight through wiring on 3 coaches since 2004 for over 200,000 tow miles and never had an issue.