Wanting to add solar to my RV, which 400 watt kit?

[jkane]

Sounds like you are set. Are your panels 20V or 41V MPP? Did you go series or parallel? In any event, you are in good shape, your SCC can utilize ~ 570W into your (assuming 12V) batteries.

The DC-DC converter is perfect for the TV to Trailer connection, you have to run independent wires for it, but that is about the only way to get more than ~8A from the TV.

 

[stillRV]

Sounds like you are set. Are your panels 20V or 41V MPP? Did you go series or parallel? In any event, you are in good shape, your SCC can utilize ~ 570W into your (assuming 12V) batteries.

The DC-DC converter is perfect for the TV to Trailer connection, you have to run independent wires for it, but that is about the only way to get more than ~8A from the TV.

They are 23v max panels: 240W 12V Monocrystalline Solar Panel

It's a motorhome, not a trailer, so most of the wiring for the DC-to-DC charger is already done. I'll just put the charger in place of the existing solenoid (the one that connects the two battery systems while the engine is running).

 

[Lou Schneider]

Check to see if there's a second solenoid in parallel as part of a boost switch to let the house batteries boost a low chassis battery. If there is and you activate it you'll short out the DC to DC converter.

 

[stillRV]

That same solenoid is used for the boost switch.

I don't believe there will be an issue shorting the positive inputs & outputs of the DC to DC charger. I plan to do this if the chassis battery is dead and needs charged from the motorhome (shore power, solar, generator, etc.). In that case the DC to DC charger would see both sides are the same voltage and do nothing. It would be the same as if the batteries were both charged to the exact same amount.

It could be a problem if it were an "isolated" charger? Mine is non-isolated: https://www.amazon.com/Victron-Energy-Orion-Tr-Non-Isolated-Bluetooth/dp/B086Q8YNJZ

 

[JayArr]

I'd try that on the workbench in the garage before you spend a bunch of time installing it all. That way if it smokes you don't have to take it all back out.

 

[aguablanco]

A better approach is to use a single 350-400 watt residential solar panel mated to a good MPPT controller like those offered by Victron most likely their 30 amp model. https://www.amazon.com/SmartSolar-MPPT-100-Charge-Controller/dp/B073ZJ3L13/ which is a good mate for around 400 watts worth of flat mounted solar panels. You can probably buy a single 380-430 watt solar panel from a local solar installer, they are big and bulky so not typically sold on Amazon, total cost will likely be $300 for the panel. Just add wires and mounting brackets and you will be good to go as long as you have room for one large panel vs 4 smaller ones.

That is exactly what I did. Bought the Trina 415W residential panel, had to mount it across the roof instead of lengthwise, a Rich Solar 40A charge controller and wires plus fuses. Total out the door ~$600. Charge controller came with Bluetooth and battery temp sensor. One of the big advantages to this set up is that I only had 6 roof penetrations for the mounting brackets as opposed to 16 for 4 100w panels. Had to make my own brackets to compensate for the curve of the roof.
Canyon

 

[DonTom]

Don, your point one doesn't make sense to me. All generators start from cold don't they?

I somehow missed replying to that old post, but I see you're still active here and was in this forum a half hour ago.

But what I was saying is it's not good for the gennys to be started cold & ran for a minute and then be shut off. If they are started from cold, it's best to get them up to normal operating temperature and have them stay there for a while before they are shut down.

This is when it is best to use an inverter instead, when you only need a few thousand watts of 120 VAC for a minute or two.

And gennys do not always start cold. You can start a generator from a warm start, such as if it was shut down a few minutes ago and now you wanna use it again. That will be better than starting it from from ice cold.

-Don- Reno, NV

 

[DonTom]

Lithium batteries charge much faster than lead acid

Is that true even if the same charge current is used as with the lead acid?

Or are you only saying you can charge lith at a much higher rate?

-Don- Reno, NV