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pteck · 10-23-2017, 09:18 AM

I'm curious what the maximum load on the 12V but on the other end of the latching relay is? Or the loads controlled by the use/store button.

I assume all the lights/fridge/stereo/fans/etc. loads, are controlled by this use/store button. Is this total load something in the 30amp range? Higher?

I see it's all connected by 6 gauge wiring so it can't be too big of a load?

Does the converter/charger also charge back to the battery across this latching relay?

I'm curious to know, as I just installed a solar setup with an MPPT controller. The controller has a LOAD terminal supporting 30amps. Was wondering if I could make use of this output to support all the loads switched by the latching relay.

uncle_bob · 10-23-2017, 09:41 AM

Hi

One would guess that AS is no more consistent in their relays than they are doing anything else. The relay in my Classic is good to at least 50A. In order to get 30A out of your solar charge controller, you will need > 600W of solar panels. If you are doing that sort of upgrade, cables that run direct to the battery are probably worth considering.

The most common point on the relay for hooking up solar is the "battery" side. The lug there is going to handle as much current as the 6GA wire. The load side of things isn't changing so the relay ratings should be fine. (Hopefully that makes sense ...)

Bob

pteck · 10-24-2017, 11:13 AM

True that there are variations.

Was just wondering if anyone has done a load test on their 12V draw with everything on. And what type current load they are seeing.

I'd like to try to plum ll the 12V loads behind the latching relay, through my solar controller, so I can take advantage of the load monitoring, and auto low-batt shutoff.

I can certainly do my own test, as I've got a clamp meter.

Though if the converter-charger, charges through the relay, I believe that's a 50amp charger, which exceeds my MPPT controller passthrough capability of 30amps.

bwoodtx · 10-24-2017, 11:39 AM

Most relays I have seen have their maximum draw imprinted on the relay.

uncle_bob · 10-24-2017, 11:51 AM

Quote:

Originally Posted by pteck

True that there are variations.

Was just wondering if anyone has done a load test on their 12V draw with everything on. And what type current load they are seeing.

I'd like to try to plum ll the 12V loads behind the latching relay, through my solar controller, so I can take advantage of the load monitoring, and auto low-batt shutoff.

I can certainly do my own test, as I've got a clamp meter.

Though if the converter-charger, charges through the relay, I believe that's a 50amp charger, which exceeds my MPPT controller passthrough capability of 30amps.

Hi

I can pretty much guarantee that my relay sees 55A on a regular basis. It's a safe bet it is rated to take it.

Total 12V load on the trailer is "interesting". The inverter is the big power user. They wire it straight to the battery. The solar side does the same thing. The converter does or does not go through the relay depending on which way the wind is blowing in JC the day they do the drawings

Hitch jack goes straight to the battery as does the breakaway cable power.

The stuff that is on the other side of the relay is the fridge, the water pump, a bunch of lights, the door bell, and all the weird small loads like the stove ignitor. I doubt they all add up to much over 10A.

Bottom line is that the converter would be the big power item through the relay (if it is on the load side).

If you are trying to do a shutdown, the inverter is your big issue. It presents a current drain even when powered off. Full up running it will pull over 100A. Things like the propane detector are also a constant load and you don't want to dump that.

Bob

mixedpuppy · 10-28-2017, 11:38 PM

When I upgraded to lithium, I also rewired to be able to entirely isolate the battery when putting in store mode. Since I intended to add an inverter that goes through the relay, I calculated what I needed and upgraded the relay. IIRC, the original relay installed was rated for 100 amp continuous/150 amp intermittent, the Blue Sea relay I put in is (IIRC) rated for 250 amp continuous/500 intermittent. Probably overkill, but it was the only one I liked that had a manual switch on it as well.