Charging your batteries with driving

[troubleScottie]

Everyone:

So a question on charging while driving and charging in general. Sorry in advance for all the questions. I tend to over design and over build things. Obviously still designing.

My typical expected operation is that battery bank(s) will have a full charge when leaving on the trip and have various levels once stopped. And I hope to have a DC frig, so will be consuming power while traveling. I will have shore line charging capability.

I realize one can charge the batteries while driving. ( Lots of references within this site)

The first question is then what are the appropriate connections. Everyone states a fuse and isolation switch and appropriate sized wiring running to the trailer. So far so good.

In looking at the breakaway battery systems, I noticed a charger for that system. I am not sure of all the particulars, but the apparent rationale is to prevent overcharging that small battery. Note, these chargers are really cheap.

So, what should you be doing for the main trailer battery bank(s)? Should one include a DC-DC charging system like Power Stream DC Input Chargers or a Sterling Power ProCharge-B? Or would one want to just directly connect the Tow Vehicle (TV) positive to the battery? The later than depends on the TV regulator to charge the battery appropriately???

The second question is if you have 2 or more banks (over building??! ), do you use separate dc-dc charging systems or separate connections OR does one use one connection plus a auxiliary charging relay (ACR)? For shore power charging, mutli-bank chargers are the way to go.

The third question is would TV charging line interfere with the shore line charging system ie an AC converter? My view is assuming they are not both on, this should be no problem. Does one have to worry about some strange loop where the line charger is affecting other things. I am assuming that everything is connected but various circuits are not active.

The fourth question is should I also believe that charging the battery bank(s) and using them is a reasonable thing whether the TV or shore line is providing the charging? I am not concerned about keeping up on power consumption.

The fifth (and final) question is while on the subject, although I am not planning on solar power, how does that fit into the mix? Do you add a something like CTEK D250S power to have 2 DC inputs? Or is the solar controller sufficient?

Thanks in advance.

[H.A.]

I cant comment on what the mass market RV business does, but I always use house battery to actuate breakaway brakes.
Keeps things simpler and less battery expense & fuss.
One downside is if towing with a depleated house battery, of course breakaway wont work on the off chance its needed.
But not much worse than towing on often neglected breakaway battery.

Its a dedicated circuit, & for fun, I connect a LED across the contacts of the breakaway switch.
Its a visual indicator the circuit is live and circuit thru the brake magnetic actuators is good.
(Actually it only indicates at least one brake circuit is good. It cant reliably indicate if one is bad. But its better than nothing & its gizmo factor is too good to pass up. )

As far as charg whilst towing, unless your house battery is uncommon, lithium for example. Perhaps different voltage, car vs. trailer (my situation for example, one of my cars is 24v), dont think DC to DC is useful.

[pchast]

I used a relay triggered by the ignition A 10ga wire back and a solar charge controller on the house battery.
On 2 trips, total 4000 miles So Far, it has worked...

[Shadow Catcher]

We have a Progressive Dynamics converter, Morningstar solar controller 150AH AGM battery and a Waeco refrigerator that is powered by 12V. The TV a Subaru outback has two 10ga lines from the battery one running to the back of the TV to power the refrigerator the other to the tear battery. I did not install a relay/diode to prevent back feeding, the solar panel and tear battery provide power to the TV battery and hence the refrigerator when stopped. I could potentially recharge the TV battery.
The trailer battery powers the breakaway switch and we have a Victron battery monitor and I will not allow the state of charge to go below 50%.
It all plays well together.