Hello from Idaho

[Riverbug]

Wow I have a lot of research ahead of me and already have questions. Did you DIY your batteries and if so what are you using for BMS? Do you have communication (like cannbus) between the BMS and inverter? Do you heat the batteries for cold weather charging? The battery technology has vastly improved in the past year with unbelievable storage and load capacity.

Chad I see we think alike on floor plans it was a good choice for our needs and style.

Thanks Larry

Hi Larry. Yes, mine are DIY. I started with a SOK 206AH LiFePO4 and went from there toward DIY knowing that I wanted to end up with alot of capacity but was not going to pay the prices at the time. There are many good options out there today but still very spendy to get the capacity we're talking about for A/C use over several days.

I'm running all JK BMS'. They do not talk to the inverter or cerbo but you have all the control you need between the JK bluetooth app, inverter settings, shunt monitoring, and other devices. I'm running all Victron which are pretty good at all the communications. Having the battery communicate directly with the inverter would be a nice to have but not a must have.

The JK BMS' I have low and high temp cutoff and heat options, but I have not installed heat pads to date. I have various bluetooth thermometers in the RV and find that the storage bay is within about 7 degrees of the main cabin so by the time it's cold enough to concern battery charging the furnace is on and I don't worry about charging the batteries. If it's going to be sitting at home in the winter and I haven't taken the batteries out, I run them down to about 50% and turn them off through the JK BMS app. You can select any settings you want basically, such as charge only, discharge only, both, etc. If I ever decide I need the heater, I will add them.

Hope that helps. Happy to answer more questions if you have them. I found learning about all of this was a fun process. As a newbie I made mistakes like anyone else. One thing I would do differently is to go 24V rather than 12V. Some would say 48V is better. I had purchased my 12V inverter already otherwise I would have made that change before I got too far along.

[M&Lcamping]

Welcome and congrats! Good floorplan.

If you want to run A/C off batteries consider taking time to research and build your own. Check out cells here as a starter... https://www.18650batterystore.com/co...rismatic-cells

@Riverbug - thank you for the battery link, I've been vacillating between building or buying a Lifepo - wonder if an 8-cell and in this case, 608ah can be built in 12v format

@Larryh22 --- like @huntingdog states, running AC with a gen is what we do as well

[Riverbug]

@Riverbug - thank you for the battery link, I've been vacillating between building or buying a Lifepo - wonder if an 8-cell and in this case, 608ah can be built in 12v format

@Larryh22 --- like @huntingdog states, running AC with a gen is what we do as well

I suppose you could build an 8 cell 12V, but if you went the route of buying 8 cells it would be more efficient to go 24V; even with the 24V to 12V converter you would have to install. While you might lose some efficiency with the 12V converter, the 120V side is going to be more efficient. But to answer your question, yes, you would have to put 4x2 cells in parallel, then the 4 paralleled cell pairs into series for 12V. But 8 cells in series for 24V would provide as much AH capacity and again run more efficiently. And you can use smaller gauge wire to save money.

[M&Lcamping]

I suppose you could build an 8 cell 12V, but if you went the route of buying 8 cells it would be more efficient to go 24V; even with the 24V to 12V converter you would have to install. While you might lose some efficiency with the 12V converter, the 120V side is going to be more efficient. But to answer your question, yes, you would have to put 4x2 cells in parallel, then the 4 paralleled cell pairs into series for 12V. But 8 cells in series for 24V would provide as much AH capacity and again run more efficiently. And you can use smaller gauge wire to save money.

Thank you Chad

[Riverbug]

Thank you Chad

No problem at all. But I need to correct/clarify something. 8 cells at 24V would provide as much Watt capacity as 8 cells paralleled/series at 12V. Not AH capacity as I stated earlier. And it assumes that the cells were of the same AH rating between the two options. So, assume each cell is 100AH and you purchased 8 of them.

At 12V you would have 200AH (whether built in parallel/series as one battery or two separate 12V batteries) 12V x 200AH = 2400W
At 24V you would have 100AH (each cell being 100AH, all cells in series for 24V) 24V x 100AH = 2400W

Again, you end up with the same capacity but at 24V more efficient and you save money on wiring (not to mention easier to deal with), but you would need a 24V to 12V converter to run your 12V devices off the 24V battery. They are not very expensive though.

Just felt I needed to correct and clarify that.

[M&Lcamping]

No problem at all. But I need to correct/clarify something. 8 cells at 24V would provide as much Watt capacity as 8 cells paralleled/series at 12V. Not AH capacity as I stated earlier. And it assumes that the cells were of the same AH rating between the two options. So, assume each cell is 100AH and you purchased 8 of them.

At 12V you would have 200AH (whether built in parallel/series as one battery or two separate 12V batteries) 12V x 200AH = 2400W
At 24V you would have 100AH (each cell being 100AH, all cells in series for 24V) 24V x 100AH = 2400W

Again, you end up with the same capacity but at 24V more efficient and you save money on wiring (not to mention easier to deal with), but you would need a 24V to 12V converter to run your 12V devices off the 24V battery. They are not very expensive though.

Just felt I needed to correct and clarify that.

Excellent, thank you

[Larryh22]

Hi Larry. Yes, mine are DIY. I started with a SOK 206AH LiFePO4 and went from there toward DIY knowing that I wanted to end up with alot of capacity but was not going to pay the prices at the time. There are many good options out there today but still very spendy to get the capacity we're talking about for A/C use over several days.

I'm running all JK BMS'. They do not talk to the inverter or cerbo but you have all the control you need between the JK bluetooth app, inverter settings, shunt monitoring, and other devices. I'm running all Victron which are pretty good at all the communications. Having the battery communicate directly with the inverter would be a nice to have but not a must have.

The JK BMS' I have low and high temp cutoff and heat options, but I have not installed heat pads to date. I have various bluetooth thermometers in the RV and find that the storage bay is within about 7 degrees of the main cabin so by the time it's cold enough to concern battery charging the furnace is on and I don't worry about charging the batteries. If it's going to be sitting at home in the winter and I haven't taken the batteries out, I run them down to about 50% and turn them off through the JK BMS app. You can select any settings you want basically, such as charge only, discharge only, both, etc. If I ever decide I need the heater, I will add them.

Hope that helps. Happy to answer more questions if you have them. I found learning about all of this was a fun process. As a newbie I made mistakes like anyone else. One thing I would do differently is to go 24V rather than 12V. Some would say 48V is better. I had purchased my 12V inverter already otherwise I would have made that change before I got too far along.

Chad you are very knowledgeable and helpful I appreciate your opinion and the benefit of your experience thank you for your reply.

Having just purchased the new trailer including suspensions mods and accessories like backup cam, tpms, xbraces and new weight distribution hitch I'm progressing slowly into more battery storage and solar. Right now I'm pleased to have a working 40a mppt solar charge controller and a single 180w panel as this will make it easy to add a couple more solar panels. Moving the batteries into the storage bay is a great ide the challenge for me is it is difficult for me to work inside there. I really like the idea of going 24v and since I don't have an inverter yet I think this is the time to plan for the higher voltage.

Some questions I have. Do you have an automatic transfer switch for shore power or an inverter with ats? My inverter prep pre-wired main breaker panel is split into two with one side for the inverter circuits such as outlets but not the a/c. Because the a/c and other circuits are not on the inverter prep side I want to know, did you tie the two sides together for the a/c on inverter? My GD manual lists ac as 14-18 amp load and I'm thinking 3000w inverter would provide ample power 25a giving some headroom (7 amps) for lights and water pump etc.

My list of components to make the system;
* two additional 180w solar panels for 540w roof mounted + 100w portable
* 3000w Inverter
** charge controller my 40a furrion mppt will run 24v loads I think this will be adequate
* voltage step down 24v to 12v
* automatic transfer switch?
* assemble 24v +400ah storage

Whew this is exciting.

[Riverbug]

Chad you are very knowledgeable and helpful I appreciate your opinion and the benefit of your experience thank you for your reply.

Having just purchased the new trailer including suspensions mods and accessories like backup cam, tpms, xbraces and new weight distribution hitch I'm progressing slowly into more battery storage and solar. Right now I'm pleased to have a working 40a mppt solar charge controller and a single 180w panel as this will make it easy to add a couple more solar panels. Moving the batteries into the storage bay is a great ide the challenge for me is it is difficult for me to work inside there. I really like the idea of going 24v and since I don't have an inverter yet I think this is the time to plan for the higher voltage.

Some questions I have. Do you have an automatic transfer switch for shore power or an inverter with ats? My inverter prep pre-wired main breaker panel is split into two with one side for the inverter circuits such as outlets but not the a/c. Because the a/c and other circuits are not on the inverter prep side I want to know, did you tie the two sides together for the a/c on inverter? My GD manual lists ac as 14-18 amp load and I'm thinking 3000w inverter would provide ample power 25a giving some headroom (7 amps) for lights and water pump etc.

My list of components to make the system;
* two additional 180w solar panels for 540w roof mounted + 100w portable
* 3000w Inverter
** charge controller my 40a furrion mppt will run 24v loads I think this will be adequate
* voltage step down 24v to 12v
* automatic transfer switch?
* assemble 24v +400ah storage

Whew this is exciting.

Hey Larry. Convenience, quality, capabilities usually seem to come down to how much you want to spend, of course. For me, spending more on a single unit that incorporated the transfer switch, charging, 12V conversion and 120V inversion was preferable. So I went with the Victron Multiplus. These are all-in-one units.

The short version is: Take the incoming shore power wire off of the breaker panel input and route that wire up toward the storage bay (or wherever you decide to install things); mine reached about half way. Then you splice in the wire to reach the Multiplus 120V input. Coming out of the Multiplus, you run a wire back into the breaker panel where you previously disconnected the wire. (Note: there is debate about using Romex vs stranded wire in RVs. Most people agree Romex isn't ideal as it isn't made for handling excessive vibration. However, as you'll see for yourself, there is no shortage of the manufacturers using Romex throughout the RV already. The choice is yours.) That takes care of the AC side.

Now you'll run cables for 12V between the Muliplus and the OEM 12V fuse panel, disconnecting the converter/charger.

If you go with the Multiplus or similar type of device you don't need to think about switching between AC shore power, AC inverter and DC, or anything and it's all housed in one unit. It's all automatic just like it is now with the OEM setup. My Multiplus is 12V/3000W/120A (charger). I really like all the devices I installed that are Victron. It's fantastic to have everything communicating together (solar controllers, battery monitor, Multiplus, Mopeka sensors, etc.) But it's a bigger investment than other options for sure.

Going 24V means you can use smaller cables, which will save some $$ even with requiring a step-down converter. More importantly, it would be more efficient if you get into larger battery bank and load such as running A/C.

I do get what you are saying about working in that storage bay. It ain't fun but it does work nicely to have all that stuff tucked away. The only other viable option I can think of is under the bed, which could also work, or a combination of batteries in the bay and other equipment under the bed.

Hope that's helpful.