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Thu Apr 12, 2018 5:37 pm

Hello all. I just purchased a 100 watt solar panel and charge controller. I have what I think is two options for my install.

1) connect directly to the house battery

2) back feed through my blue seas fuse panel.

Anyone install using the back feed method? I have a NOCO Genius charger and a yandina battery splitter.

Anyone reason to pick one install over the other?

Thu Apr 12, 2018 5:42 pm

I charge through my fuse block because, well fused.

Thu Apr 12, 2018 6:08 pm

I connected from the charge controller to the house battery.

Thu Apr 12, 2018 6:27 pm

I’m 99% certain I used this path:

Solar panel >>> fuse panel >>> battery (and other items connected to the fuse panel)

I also have an in-line fuse a few inches away from the battery post should the batt. cable somehow connect to ground in the run to the fuse panel.

I can’t tell you if this is an optimal arrangement.

Thu Apr 12, 2018 7:28 pm

physast wrote: Hello all. I just purchased a 100 watt solar panel and charge controller. I have what I think is two options for my install.

1) connect directly to the house battery

2) back feed through my blue seas fuse panel.

Anyone install using the back feed method? I have a NOCO Genius charger and a yandina battery splitter.

Anyone reason to pick one install over the other?

What do you mean by the "backfeed" method? I'm an electronics engineer and have not heard of it.

Thu Apr 12, 2018 7:54 pm

Basically OP wants to know if it's okay to charge aux battery by going into fuse panel to battery. Like I have in the diagram top left.

Fri Apr 13, 2018 7:34 am

Yes by back feeding I am just implying going through the fuse panel.

I think I will do an install directly at the battery. If I go through the fuse panel then I would be charging both the house and starter battery correct?

The solar panel is for camping and I want all power going to the house batteries.

Fri Apr 13, 2018 7:41 am

physast wrote: Yes by back feeding I am just implying going through the fuse panel.

I think I will do an install directly at the battery. If I go through the fuse panel then I would be charging both the house and starter battery correct?

The solar panel is for camping and I want all power going to the house batteries.

Well is your fuse panel powered by both batteries? It's hard to say if it will charge both batteries without a wiring diagram.

Fri Apr 13, 2018 8:07 am

shagginwagon83 wrote: physast wrote: Yes by back feeding I am just implying going through the fuse panel.

I think I will do an install directly at the battery. If I go through the fuse panel then I would be charging both the house and starter battery correct?

The solar panel is for camping and I want all power going to the house batteries.

Well is your fuse panel powered by both batteries? It's hard to say if it will charge both batteries without a wiring diagram.

Good point. I will need to double check. I know both batteries are charged by the alternator. The fuse panel is likely just house battery.

Fri Apr 13, 2018 8:08 am

Do you guys have an on/off switch connected to the charge controller so that the battery is not running the controller when you do not have the solar panel connected?

Fri Apr 13, 2018 8:23 am

Well in the setup I posted - when the engine is running, the relay gets a signal to turn on the SI-ACR (combine battery) unit. The unit then detects a higher voltage for 30 seconds on the starting battery - then combines the battery.

However when strictly solar charging with the engine not running - it just charges the house battery.

The solar charger should have little vampiric drain when not in use. My solar charger is bluetooth and I leave it always running.

Fri Apr 13, 2018 8:24 am

physast wrote: Yes by back feeding I am just implying going through the fuse panel.

I think I will do an install directly at the battery. If I go through the fuse panel then I would be charging both the house and starter battery correct?

The solar panel is for camping and I want all power going to the house batteries.

Fues exist to limit current to what the wiring can handle. Fuse boxes can be single source (like house battery) or individual(where you wire to each individually). You should NOT have the two batteries connected through the fuse box in any way. The ones we use are not typically rated for either the wire size or current that could happen when the batteries are connected.

I prefer to connect my battery to the solar controller through a fuse, (the fuse located close to the battery), then from the battery to the fuse box, which is a single input type. But everything connected to the fuse box is separate from the circuits that run off the starter battery.

Fri Apr 13, 2018 8:25 am

No switch on mine. No issues either.

It sounds like you may be over thinking this.

The easy way is to hook the solar controller directly to the house battery and let the battery isolator/combiner do its job of combining the starting and house batteries when there is a charging source on either one (solar or alternator) and separating them when there is not.

I do have a switch on my yandina that allows me to force a separation even if there is a charging source for when I want the solar to only go to the house batteries.

Fri Apr 13, 2018 9:30 am

dobryan wrote: No switch on mine. No issues either.

It sounds like you may be over thinking this.

The easy way is to hook the solar controller directly to the house battery and let the battery isolator/combiner do its job of combining the starting and house batteries when there is a charging source on either one (solar or alternator) and separating them when there is not.

I do have a switch on my yandina that allows me to force a separation even if there is a charging source for when I want the solar to only go to the house batteries.

I do the same for mine, although I have enough solar that I leave them separated 99% of the time. You can also force connect them, which I’m sure you know, which could be usefull if the starting battery is flakey.

Fri Apr 13, 2018 10:02 am

physast wrote: Do you guys have an on/off switch connected to the charge controller so that the battery is not running the controller when you do not have the solar panel connected?

No switch. However, when my van is parked in the garage, it gets plugged into AC power, which keeps the battery charged up via the NOCO.

As for the original question, you can do it either way, but I went with the direct-connect route with a separate in-line fuse.

Fri Apr 13, 2018 10:09 am

my solar installation is this:

solar panel -> fuse -> charge controller -> fuse -> aux. battery -> fuse -> fridge or other devices.

no on/off switch because the current goes one way only from charge controller to battery.

Fri Apr 13, 2018 7:00 pm

What model charge controller are you using? Some solar charge controllers have a dedicated port for loads which allows it to charge the battery while maintaining a regulated 12V for the load connections.

If your charge controller only has two ports, one for the PV module and another for the battery then either way will work. That being said, best practice would be to connect the charge controller directly to the battery and only connect loads to your fuse panel. This makes it easier to service the fuse panel or the connected loads in the future because removing all lugs on the positive terminal of the house battery removes all voltage sources from the house loads. ie. more intuitive for others that might work on your equipment.

Sat Apr 14, 2018 5:18 am

Just a thought on what else might be connected to the fuse panel and drawing power while you are trying to charge the batteries?

Sat Apr 14, 2018 5:34 am

Just a note to say purchase top of line controller. $50 one failed and burned down my 89 Westfalia.

Sat Apr 14, 2018 7:44 am

JudoJeff wrote: Just a note to say purchase top of line controller. $50 one failed and burned down my 89 Westfalia.

It hurts a bit to hear that story again.

Have you purchased a charge controller since and if so, what did you get?

Thanks.