I recently got 600W of solar, two 12V 100ah gel batteries, 40amp charge controller, and 2500W inverter installed on my travel trailer. The guy who installed the system disabled charging via the converter so it wouldn’t create a loop when my inverter is on. He did this because there was no switch to physically turn off the charger when I want to turn on the inverter.The problem is that I’m currently in Oregon and solar input is seriously low. We’re at a campground and our batteries are almost dead because there’s very little sunlight and charging via the 30 amp shore power is disabled. 1) How do I add a breaker/switch for the charger to my electrical panel so I can charge my batteries with shore power when my inverter is off? 2) I have a 35 amp converter charger. Can I just get a 35 amp breaker and have it installed?

Hook the convert back up to the circuit breaker. Use the circuit breaker to turn the converter on and off.

You have come to the right forum! :)So first give us the brand and model of the 35 amp converter so we can know how it gets its 120v. Some you just plug in and others are "hardwired".A 35 amp converter means only 35 amps DC. Its 120v input requires only a 15a circuit.On your 120v breaker panel, there should be one marked "CON" that might be sharing with some other 120v thing like "Receptacles" If the converter has its own breaker, that can be the switch.Your "gel" batteries are probably AGMs. There is a difference in how to recharge them. Confirm what you have there.Two 100ah batteries are not enough to run that 2500w inverter to run anything big like a microwave. OK for TV sets etc. Needs two more batteries for a MW.600w of solar is a lot with only two batteries as "storage". You can recharge them quicker than four batteries, but then you can't last as long between sunny days. (As is the situation)

35A is the output of the converter; the current at the 120V input will be considerably less than that.The basic solution is indeed to reconnect the converter with a switch or breaker dedicated to controlling it. Exactly how that might work depends some on what exact style of converter it is, whether you have extra space in your AC electric panel, and that sort of thing. One possible solution is to simply hook it up with a normal household light switch wired in to turn it on and off.Depending on how old the converter is, it might be worth considering upgrading it to a modern multi-stage converter if you expect to be using it much.

Why would any reputable installer do that?What do you mean 'gel' batteries?

How is your inverter wired into your 120v circuit breaker panelDid he add a new 30amp outlet for your shore cord to plug into?Did he run new wire to the breaker box from the inverterOrDid he install a transfer switch between shore cord and the inverterThe inverter output side must be disconnected from the house wiring when using shore powerDo Not plug into shore power until you know it is safe to do so, you risk damage to the inverter even if it is turned off, if it is not physically/electrically disconnected from the breaker panel and shore power

Disconnect/Shut off converter when inverter is on

40 Replies

pianotuna
Nomad III
Feb 04, 2020
20ldman,

The "Genius" charger claims to remove sulphation. Lots of folks drink that Kool-aid.

By charging very slowly at least the OP won't get voids in the gel.
2oldman
Explorer II
Feb 04, 2020
storyarc wrote:
The trickle charger seems to be doing the job of slowly charging and, if necessary, repairing the batteries.
Why did you choose a very slow charger?
storyarc
Explorer
Feb 04, 2020
Thanks for all the replies. We ended up getting a battery maintainer (trickle charger) to top up the batteries while we’re here at the Oregon campground and have shore power. This is the model we chose: NOCO Genius G3500 6V/12V 3.5 Amp Battery Charger and Maintainer https://www.amazon.com/dp/B004LWVEKS/ref=cm_sw_r_cp_api_i_I4zoEbB5JTC5E

We hooked it up yesterday afternoon. Our batteries were under 25%. We woke up with the batteries at 64%. Normally, since arriving in Oregon, we wake to find the batteries dead or nearly dead. The trickle charger seems to be doing the job of slowly charging and, if necessary, repairing the batteries. I’ll report back if anything changes.

Thanks!
2oldman
Explorer II
Feb 03, 2020
pianotuna wrote:
In any event, Gel may not be an ideal choice for an RV.
Very strange installation.
BFL13
Explorer II
Feb 02, 2020
Trojan says to use 10-13% of C20 to recharge Gels

C20 is the AH capacity using the 20 hr rate (which is a discharge rate of 5% of capacity, C/20--capacity divided by 20 )

So the OP's two 100s would be recharged at 20-26 amps, max. If they were AGMs that would be 20% of C20 or 40 amps.

AFAIK, discharge and recharge limits are the same to allow time for the chemical reaction in the battery, but not sure on that. If so, then max inverter draw on the two Gels would be with a 260w 120v appliance, or 520w with four of those 100AH Gels

However we usually say you need about 440AH to run a microwave which is say 140 amps, so that is 140/440 = 32%, and recharging AGM or Flooded batts at 32% is allowed. My AGMs do say 27-30% though.

https://www.trojanbattery.com/pdf/TrojanBattery_UsersGuide.pdf
pianotuna
Nomad III
Feb 02, 2020
The quote does not include discharge rates, only recharging rates.

In any event, Gel may not be an ideal choice for an RV.
BFL13
Explorer II
Feb 02, 2020
Had to edit earlier post about PT's quote re C/20 charging rate for Gels. C/20 is the 20 hr rate. Got confused with ?? C.20 ?? as the 20% charging rate??? All a muddle now :(

Anyway, if it is the 20 hr rate that is 5 amps per 100 AH so charging/discharging limit on two 100AH gels would be 10 amps! That does not seem right? With four your inverter limit would be only 200w of 120 appliances.
time2roll
Nomad
Feb 01, 2020
I assume the WFCO is fine to give the battery a boost when solar is weak.
General charging will be solar and should be programmed to match the battery charging specs.
A third charger is not needed.
BFL13
Explorer II
Feb 01, 2020
pianotuna wrote:
Hi BFL13,

What is "LY"?

Scroll down to landyacht318's post

https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/30025966/gotomsg/30026947.cfm#30026947
pianotuna
Nomad III
Feb 01, 2020
Hi BFL13,

What is "LY"?

Forum Discussion

Disconnect/Shut off converter when inverter is on

40 Replies

About Technical Issues

Related Content

Inverter install

Inverter/Converter

Inverter/Converter

80 amp converter and eu2000i

Can i replace a 55amp converter with a 35amp converter in motorhome if i only use it a few times a y