Lithium and 3000w Charger Inverter Upgrade

[WV John]

Hoping that someone has had some experience with this electrical question. I have a 2021 Regency Ultra Brougham. It came with AGM batteries and a Renogy 2000w Inverter that powers some lights, the TV, and a couple of receptacles. The main things not powered are the AC and the Microwave.
I have a diesel generator.
The Power supply system is shown in attached pic where everything above the Inverter/Main breaker is only supplied by the inverter
and everything below the Transfer/Main is supplied by only shore or generator power. (the power system with converter is the WFCO WF-9580 power center)
I didn't know until today that the converter (charging system) in that power center is not ideal for Lithium batteries.

What i want to accomplish is:
1) not damage my lithium batteries (I have 3 100 amp 112v Renogy batteries hooked up in parallel) and to be able to fully charge them on shore or generator power
and for sure 2) be able to run my Air Conditioning or microwave for short periods of time on the Lithium batteries

One idea was to install the 3000w inverter in addition to the 2000w inverter and let the 3000w inverter only supply a separate sub-circuit of the Air Condition and microwave (but that is not ideal at all!)
The Renogy 3000w inverter charger has a built in transfer switch and charger so it would be nice if I could just use that system possibly by just turning OFF the circuit breaker to the "charge controller" on the WF-9580 power center.

ANY ideas would be GREATLY aprreciated!
Thanks

[creativepart]

I hate to be the one to give you the bad news, but 300 amp hours of LiPo4 batteries are not enough to run your A/C for a meaningful amount of time. You have 3,600 watt hours available.

An average 15,000 BTU RV air conditioner will require about 1,500 watts to run. However, it will need about 3,000 watts or even 3,500 watts start-up wattage.

We keep seeing folks show up on IRV2 with the mistaken idea that a couple or three hundred amp hours is a lot o power and therefore plenty to run their A/C for a couple of hours to "cool off" the RV.

With a 3000w inverter and 300 amp hours of lithium batteries you will be able to start and run one A/C unit for a short while. Maybe an hour if you aren't running anything else. And, at the end of that time your batteries will be totally depleted until you connect to shore power or run a generator and charge them back up.

And, if you're just going to have to run a generator to get your batteries charged up you might as well just use that generator to run your A/C.

I'm not sure how to wrap my mind around the two inverter part of your plan. Remember, both inverters will be drawing from the same 300 amp hours of batteries.

Don't despair, those 3 LiPo4 batteries are a great foundation for your plans to upgrade to a 3000w inverter/charger (to replace your 2000w inverter and Converter's charger).

[vsheetz]

A typically roof air conditioner by itself will consume about 100-150ah of battery, per hour of usage. And then that has to be replaced by generator or shire power. So, yes, for a short time it can be done. But the net result doesn't gain much, unless you have a specific scenario where it might.

An additional and separate inverter/charger is a way to go. Or replace and power everything with something like a Victron inverter/charger.

###

Another avenue...

With a hybrid inverter such as the victron you can use your lithium batteries to augment a limited shore power connection, such as a 30a or 20a. I do this - I'm currently on a 20a shore circuit and running air conditioning and other items. The shore power will replenish my 600ah lithium battery bank through the night when air conditioning no longer needed.

[WV John]

Thanks @vsheetz and @creativepart

Wonder if I could come off of my existing "transfer switch" ( I am assuming it works to transfer between shore or generator 110ac ) as an input into my Renogy 3000w inverter charger and then output the inverter charger to both the bottom and top halfs of the WF-9580 power center (and then just cut the breaker to the WF-9580 charge controller) .... all this since the Renogy inverter charger has a built in transfer switch and charge controller.
Of course everything would have the potential of being powered by the inverter I would just have to avoid turning on too much and causing an overload -- that would also set me up if I added more batteries - I'm pretty sure I could add 3 or 4 more batteries under my couch ???

Main thing I can't figure out is how to get the power center re-wired

[HarryStone]

You can move the microwave breaker from the AC transfer side to the inverter side. The only concern would be overloading the inverter side of the circuit, but since you have several 20 amp breakers already on the transfer side, it 'shouldn't' be a problem. The 3k inverter will replace your existing inverter and will have pass through capability and an internal transfer switch, along with having lithium charger capability. You should look at the AC wire size going to the inverter. A 2K and a 3K inverter have slightly different requirements. you will be able to turn off the converter breaker and not worry about it anymore.

[WV John]

Originally Posted by HarryStone

You can move the microwave breaker from the AC transfer side to the inverter side. The only concern would be overloading the inverter side of the circuit, but since you have several 20 amp breakers already on the transfer side, it 'shouldn't' be a problem. The 3k inverter will replace your existing inverter and will have pass through capability and an internal transfer switch, along with having lithium charger capability. You should look at the AC wire size going to the inverter. A 2K and a 3K inverter have slightly different requirements. you will be able to turn off the converter breaker and not worry about it anymore.

What would happen if I just powered both sides of the power center with the inverter
So I would just be running the shore / generator to the inverter (with its built in transfer switch) and then just run the output from the inverter to both sides of the power center?

[HarryStone]

Your new inverter can only handle 30 amps, actually a bit less. 3000 / 120 is actually 25 amps.

[WV John]

Originally Posted by HarryStone

Your new inverter can only handle 30 amps, actually a bit less. 3000 / 120 is actually 25 amps.

So (lol) I am trying my best to not sound stupid but if I left things as they except maybe moving the microwave breaker to the inverter side of the power center and making sure that the existing converter (on the power center) was turned off
Then where would I get the AC power input to send to my new 3000w inverter charger? Should I just wire it from the existing output for the converter maybe? I just know that I need AC power input into the new inverter charger to be able to get my batteries to charge from shore or generator.

[Danny969]

Your 2000w inverter should probably run your microwave. I had a 2000w inverter with 200 amp of lithium and my 1600w microwave worked just fine. Your 300 amp of AGMs may not be enough, however, depends on their output capability. As far as your AC goes, a 3000w inverter is probably needed, but it depends on the draw of the AC unit and whether it has soft start and the output capability of your batteries. 300 amp AGM is not enough.

[Tskadberg]

Originally Posted by WV John

So (lol) I am trying my best to not sound stupid but if I left things as they except maybe moving the microwave breaker to the inverter side of the power center and making sure that the existing converter (on the power center) was turned off

Then where would I get the AC power input to send to my new 3000w inverter charger? Should I just wire it from the existing output for the converter maybe? I just know that I need AC power input into the new inverter charger to be able to get my batteries to charge from shore or generator.

Is it an option to return your new inverter and get a Victron Multiplus? That’s what I ended up doing after going down the same road you are on. It’s a big job but simpler and more useful than what you are trying to do.

[HarryStone]

Originally Posted by WV John

So (lol) I am trying my best to not sound stupid but if I left things as they except maybe moving the microwave breaker to the inverter side of the power center and making sure that the existing converter (on the power center) was turned off
Then where would I get the AC power input to send to my new 3000w inverter charger? Should I just wire it from the existing output for the converter maybe? I just know that I need AC power input into the new inverter charger to be able to get my batteries to charge from shore or generator.

I was basing my answer on the idea that you would replace the 2k inverter with the 3k one, not have both. To have both would require additional wiring and the addition of a sub panel to power those circuits that would be on the 3k inverter.

[jpc123]

Some thing to think about.
The 3000K Victron Multiplus can assist in a 30A shore connection providing up to an additional 25A. Wont you need to have 6AWG wires going to and from the inverter?

[Tskadberg]

Originally Posted by jpc123

Some thing to think about.
The 3000K Victron Multiplus can assist in a 30A shore connection providing up to an additional 25A. Wont you need to have 6AWG wires going to and from the inverter?

Absolutely. Our Multiplus has the whole 2 pole 50amp running through it with 6 gauge.

[WV John]

Originally Posted by HarryStone

Your new inverter can only handle 30 amps, actually a bit less. 3000 / 120 is actually 25 amps.

Hello sir @HarryStone - this thread is a bit old but I hopefully need some help.
I was able to complete my project with install of the Renogy 3000w inverter charger. I now have 3 100amp Renogy Li batteries up front and 2 200amp batteries in the back. I did some testing earlier in the spring and was able to run the AC full blast for about 5 1/2 hrs! on that 700 amps

We have been very busy and have not been able to plan any trips ... so today I was messing aroung in the rig and turned the AC on while on shore power (we have a 30 amp connection). The AC would start and run 30 seconds or so then the Renogy charger inverter would shutdown and get a loud continuous beep. Had to cycle the inverter off and then back on. What could be the problem that the Renogy wont power the AC while on shore power ???