Just another solar/lithium install

subfreq111

After lots of reading and research here and other places on the interwebs, we pulled the trigger on augmenting our T@B 320S's (The Strawberry Wagon) power system. Since we prefer to camp in out of the way areas as opposed to inside campgrounds with electrical service, we were looking for a way to be electrically self sufficient for extended periods. Even on the occasion that we stay in a campground in a National Park, most sites still don't have electric, so we're still basically boondocking. Anyway, here's what we went with.

3x Renogy 160W flexible mono panels
1x Renogy 50W flexible mono panel
40A Renogy Rover Li Solar Controller w/ Bluetooth
30A Automatic transfer switch
3000W Renogy Pure Sine Inverter
500A Renogy Battery Monitor
2x Renogy 170Ah LiFePO4 Batteries

Total 530W possible solar output and 340Ah battery storage(+~50Ah in original battery for 12V system)

Panels are attached to the roof using 3M VHB tape around the perimeter of each panel, about an inch in from the edge
Wires come in through waterproof panel located above A/C so A/C drip pan catches any possible leakage and run down wall behind TV to electrical cabinet
Inverter and charge controller are mounted inside electrical cabinet to fabricated wood mounts
Transfer switch fits behind WFCO panel and automatically supplies AC power from shore power or inverter to WFCO AC distribution
Battery monitor mounts above Alde control panel (only making 170W at the time, but still early morning)
Battery cables pass through the plumbing compartment inside a 1.25" PVC parallel to the existing pipe
Batteries fit perfectly in left rear storage behind Alde unit that's rather difficult to access for other purposes (only on their side because lithium, don't try this with lead acid batteries)
Cables running from battery to inverter are 2/0 with 200A fuse installed. PV cables are 10awg and charging cables are 8awg. Hydraulic crimpers were extremely helpful for making large connections.
I was going to remove the original battery from the tongue box and replace with a second propane tank, but have decided for now to leave it in place to run all the 12V accessories and I will charge it as needed using the inverter and/or tow vehicle. This allows me to keep the OEM system and the new lithium system isolated unless I choose to charge. I may change this in the future if it seems I need more propane than battery.

I'm still fully charging the batteries for the first time but I'm eager to see Air Conditioning run time with this set up. Between the A/C itself and the inverter, it looks like consumption is just under 500W combined, so 4-6 hours of A/C use per day should be no problem at all. 

I still need to tie the loops down on the right side and mount the inverter remote switch, but I'm about finished. Would love to hear any suggestions or happy to answer any questions. 

Bayliss

Looks like a very clean install, @subfreq111.  I don't think you are going to be running out of "juice" any time soon.     Thanks for including the photos.....always appreciated.

digitaldean

That's a lot of solar real estate! Panels wired in series or parallel? They look like the same high efficiency flex panels I installed, they perform great. If I ever wanted to install an invertor I was thinking of putting it where you did, but never thought of lithium batteries in the Alde area. Nice. 

DougH

@subfreq111 ; Nice setup! We're hybrid / separated on our rear vs. front batteries too.  How do you plan to keep the inverter ventilated, or do you only camp in cooler climes?

subfreq111

They are all four in series to reduce current between the panels and controller. Open circuit voltage is around 96V and operating voltage is about 55V.

subfreq111

@DougH I've only heard the fans kick on in the inverter when I loaded it up with 2.4 KW of the Alde running full tilt and the A/C. If inverter cooling becomes an issue, I imagine I'd leave the lid open on that compartment or explore adding some speed holes to the face of the cabinet.

DougH

OMG the Alde + A/C simultaneously!!!  Filled with awe and wonder!  But a thermal sensor, relay and fan into the main cabin or through a hole in the floor would do.  Next obvious step is to add electric motor hubs to the T@B wheels so you can power up mountains... 

jkjenn

I am glad to see some competition in the RV lithium battery market to help drive down the costs. I am not sure if Battle Born is really the best player in the game or if they just got to all of the big social media influences, first.

N7SHG_Ham

@jkjenn have you watched the Renogy tear down?

https://youtu.be/aahHWaV6Zdk

BB is good , but they also get a lot of publicity, best? The warranty is still one if not the best and that probably sells a lot for them.

jkjenn

N7SHG_Ham said:

@jkjenn have you watched the Renogy tear down?

https://youtu.be/aahHWaV6Zdk

BB is good , but they also get a lot of publicity, best? The warranty is still one if not the best and that probably sells a lot for them.

I have nothing against BB, just looking for more competition and variety. Both are good for the consumer. 

Hard for me to justify lithium, for myself, given the current investment entry point. But, I do watch other people's installs with curiosity.

N7SHG_Ham

I have learned a lot watching Will's channel, he is very informative and entertaining while really geeking out on technology.

JCALD

That is a really sweet solar setup you have.  Would you mind sharing how much you invested in it so the rest of us can plan our savings.

Tundra57

Have you done an actual run with ac running off the inverter via the batteries? What was the battery bank voltage after sau three hours like you mentioned? How does the inverter handle the ac start surge?

The renogy inverters I've seen have a built in shore power or battery switch automatic changeover. Also a battery charger. What part did you use?

subfreq111

@JCALD I would guess roughly 5000 for the parts I have to add this system. @Tundra57 I get about 10 hours runtime without solar and 15 hours with solar charging. Because lithium, the bank voltage holds steady at 13.3 until the last 10 percent does it start to drop off. The inverter is rated 3000w continuous and 6000 surge so startup is no problem with start surge. I would guess a 2000w would probably do the job but 3000 wasn’t much more and I would prefer a little overkill. Renogy makes both inverters and inverter chargers that have the features that you describe but the inverter chargers are much more expensive and huge. I decided the transfer switch fo 50 bucks and a lithium battery tender for 40 was a better use of funds.

Tundra57

@subfreq111 That sounds really good. I am fitting two more AGM batteries to make me 440 Ah and have toyed with replacing my 1200Watt invertrr for a bigger one. Do you have the rough dims of your 3000Watt?

subfreq111

@Tundra57 keep in mind AGM batteries can only be discharged to 50% compared to Lithium that allow use of the full capacity. This is the unit I used. Looks like 19x9x4" https://www.renogy.com/3000w-12v-pure-sine-wave-inverter/

Tundra57

@subfreq111 Yeah i heard that. Im researching the 50% thing. I have double what i had before. If i decide to go Lithium later, there will be tons of room to put batteries. It is a boon with the lithiums to hold voltage until the last, as that reduces the current draw on the battery.

I have the factory 200W solar and added another renogy 200W external. Not up to your standards. To run AC i would have to run another power socket or just use a transfer switch like you. Hey that means the battery charges itself lol.

Tundra57

@subfreq111 i did a lot of research. You can discharge agm batteries ,to 20%, often. According to manufacturers data, comparing discharge at 50% to discharge to 20%

Reduces the lifespan by a third. A very important requirement in any discharge state is to recharge as soon as possible so that the amount of crystallization at the plates is reduced. This is the primary cause reducing battery life.

Generally an AGM battery will be toast in 10 years or less. So with the above data if it lasts 10 years discharging to 50% then discharging to 20%  takes its life to 7years. So cost wise an AGM may be a better bang for the buck, but, its bigger and heavier.

There is so much data out there, i went with the most popular data from battery manufacturers.

Since I have 4 x 220Ah 6V agm's Ill be seeing how long they last. The first two have done 1 year so far.

DougH

Tundra57 said:

<snip> Hey that means the battery charges itself lol.

@Tundra57 ; I've got a Frankenstein setup where my inverter, powered by solar & two batteries in the back, can plug into the AC grid as if on shore power, and thus let the WFCO charge the front battery.  Or I can close another battery disconnect switch to bridge the rear and front batteries for maximum DC juice on the road (running fridge or basement heat).  But to your point, if I had both the batteries bridged, and the inverter powering the AC grid, how much energy am I wasting and how fast?  Would it essentially be the 6A (?) bulk charge rate of the WFCO?

subfreq111

@DougH, just like you're describing, when I am disconnected from shore power and turn the inverter on, all the original equipment sees the incoming AC as shore power. This causes the WFCO to charge the original battery, unless I pull the bottom fuse to disable the converter. I see no problem with the DC-AC-DC conversion and solar has no trouble keeping up. On a partially discharged battery, I normally see about a 100W draw by the inverter/converter, which could run all night without issue, and in daylight is far less than solar is producing.

DougH

@subfreq111 ; Thank you so much. I was curious how I could bridge the batteries and not charge the front battery when on inverter power. Very nice to hear its just the bottom fuse. Guess I should convert that into a combination fuse and switch.

subfreq111

@DougH, I considered different methods to prevent charging the OE battery off the new one including relays and other methods, but since the converter is totally integrated with the WFCO, pulling the fuse seems to be the simplest. I believe it's labeled as reverse polarity protection and is a 40A.

DougH

@subfreq111 ; So I assumed I could find a device with two male fuse blades, but with a couple 16AWG wires coming off those blades.  That way I can put a switch and a 40A fuse in that circuit and mount the converter bypass switch right next to the WFCO (to avoid excessive wear on that WFCO 40A converter receptacle).  I looked on Amazon and there's plenty of 12V Add-A-Circuit taps, some with an extra fuse for the secondary circuit...  but nothing as simple as two blades each attached to a wire held in a fuse like plastic holder.  Guess I don't know the keyword such an animal is called, or I need to just create a handmade animal with that functionality myself.

Close but with Mini blades:  https://www.amazon.com/dp/B07TWXMHRV

Tundra57

@subfreq111. I like your solution with transfer switch. I thought id be smart and buy the inverter with integrated charger and transfer switch. But as you said very expensive about $1,000. Also the renogy has only a 25Amp transfer rating.

So im back to your solution of a 3000watt renogy inverter and an automatic transfer switch.

So that is my next project, probably next month. I have 440 Ah of AGM and a but less than 400watts solar. I can remove the factory 1200 watt unit and fit the new inverter there.  Its right next to the batteries.

Just got to find a spot for the transfer switch. Somewhere in the same area.

I'm quite excited to try it.

I did not imagine you could get 10 hours running the AC. I calculated maybe 4 without solar. But I have a Tab 400 and a coolcat AC with soft start. So maybe it is a  larger unit than your Tab.

Guess ill find out lol. 

Even if I can cool the tab down before bed that would help. There is no way it can run all night.

Thanks for the ideas.

Tundra57

@subfreq111 is your renogy inverter still working? Seems there are a lot of different manufacturers, but a lot of them dont last long either.

subfreq111

@Tundra57 my Danby AC consumes about 460W on hi, not sure if the Coolcat is more. I would expect that once it gets cooled down, it will cycle on and off, so your 4 hours of run time may really be 8 hours worth of cooling with it running 50% of the time. When the compressor turns off and it's only the fan running, my AC drops to only about 50W. 

As for the inverter, I had trouble with the first one, it kept showing a ground fault when turned on, even with nothing plugged in. Amazon replaced it for me and no issues so far. 

Tundra57

@subfreq111 That explains the difference. Thanks. Seems three big players, renogy, aims, magnum. Just deciding which. I assume you turn off the breaker for the charger when running off the inverter? I might see if i can run mine through a spare contact on the auto transfer switch.

DougH

I've been through several inverters too, but finally am on a 2200W Giandel pure sine wave that has been reliable.  Weird thing is Amazon wants $339 for it:

https://www.amazon.com/dp/B07CKBJ9KP

... and Walmart wants $1205 for it:

https://www.walmart.com/ip/20A-RV-Port-Remote-Sine-System-2200W-120V-Control-12V-Control-LED-Inverter-AC-Solar-USB-Charge-1x2-4A-Truck-Giandel-Outlets-Wave-Car-Dual-Pure-Power-/206458946

I do have an exhaust fan through the floor right next to it, and it also is visco-elastic shock mounted so it gets less vibrations on the road.  Fused on both input and output sides.

Pulling that converter 40A fuse means I also lose any 12V lights and fans.  Maybe that cannot be helped and is the price of running all AC outlets and air conditioner off the inverter, without charging the front battery.

Sprockethead

NICE Setup subfreq111... I really like the Battery location!, I have problems with too much Tongue Weight. I have a Huge AGM battery in the Tub.

I also noticed comments about Inverter Surge Capacity. I've been through Three of the AIMS 200 watt units. I finally called the manufacturer, they told me the Surge Capacity is only for 40 milliseconds!... Most loads draw for much longer than that, Especially an Air Conditioner!
https://www.aimscorp.net/2000-Watt-Pure-Sine-Wave-Inverter.html

The Micro-Air "Easy Start" is my solution. They helped me find one for my T@B 320S window unit. This Mod also allows me to run AC using the tiny Honda 1000 watt generator

subfreq111

@Tundra57 not sure what breaker you're talking about, I allow the DC converter to charge the OEM battery when the inverter is on. @DougH, at least on mine, the 40A reverse polarity circuit fuse only disables the converter, I still am able to use all other 12V circuits with that fuse removed. 

Tundra57

@subfreq111 . I have a seperate ac power breaker for the battery charger. I only have one set of batteries. So when the inverter is running off those batteries, I dont want the charger also running to charge the same batteries. It just wastes energy. If perpetual motion and room temp superconductors  were a reality, I would not be concerned lol.