Help me think this through (solar/batteries/generator, etc.)

**SolarPoweredRV** · 08-06-2022, 11:45 AM

Originally Posted by Second Chance

Baseline: we ordered our 2020 Solitude with a residential fridge and solar, so it has the stock 300W solar panel, 30 amp Jaboni MPPT controller, ATS, sub-panel, and 2,000W inverter. We put two BB 100Ah LiFePO4 batteries in it on arrival. Our intent was to keep the refrigerator running on travel days and the setup has performed that task very well. We don't boondock.

We've experienced several power outages in the 2-1/2 years since taking delivery of the Solitude. The longest was when a fencing contractor on Aberdeen Proving Ground knocked a transformer off its concrete base and blew a few things up the line. That outage was about four hours - but the sun was out (solar was cranking out the watts) and it was a weekday so the power company got on it immediately (was a bit warm, but we put our recliners under a nice shade tree and read our Kindles). The most recent was last night after a lightening strike on the perimeter of the park. Power was out about 2-1/2 hours before coming back on. At about the two-hour point (10:00PM), the Battle Borns were at 13.2 volts (about 70%?). We were conserving power as much as possible, but it was late in the evening and it was dark (no solar).

Laura has brought up the topic of a generator every time these situations have occurred - and this morning was no different. I want to lay out several scenarios and solicit input. There are a lot of you out there with a better handle on this than I have and I would like to pose some questions (and certainly wouldn't mind if @SolarPoweredRV were to chime in

).

1) Had the power not come back on, I'm not sure the BBs would have kept the fridge running until the sun came up and started hitting the solar panel this morning. Based on the 13.2 volts after approx. two hours, am I right about this or worrying about nothing?

2) Could I add two more BB 100Ah batteries - perhaps replacing the cables with busses - without changing the rest of the setup? I know it would take the converter/charger and the 300 watts of solar longer to recharge them, but would four of the BBs get us all the way through a night with power conservation... even in the winter with the furnace cycling? (And - would there be an issue with adding two of the new series BBs to the two existing BBs?)

3) We're not going to consider an on-board generator installation. It's just not worth it for us. In looking at portable generators, there are several constraints. I'm getting too old to lift a large/heavy generator in and out of the truck bed. The Honda EU2200i is a really nice unit, but would have just enough output to keep the batteries charged, run the fridge, and charge some of our other devices. Even with Easy Starts on the ACs, two of the Hondas ganged would be pushing it for a 15K AC plus the other loads, wouldn't it?

If one of the Hondas would get us over the hump similar to two additional BB batteries, that option would be about $700 cheaper - but I would have to get out the generator and adapters, connect everything, and start the generator... then refuel during the night if there were more than 1/4 load on the generator. If adding two more BBs were to be viable/compatible, I wouldn't have to do all that (worth $700 to me).

If there are other options, I would love to hear about them!

Thanks!

Rob

Thanks Rob, here are my thoughts:

1) Your refrigerator is well insulated and can keep your food cold and safe for a few hours (maybe as many as 4) without power, as long as you are not opening the doors. The Freezer will keep your food safe for probably 6 to 8 hours, however, I would not refreeze the contents and would eat everything within a week if you face an outage that long. Consequently, you could probably make it safely through a night with your present setup, in the morning your Solar should be able to power the refrigerator, however, I would shut off the refrigerator until the batteries had at least 10% SOC.

You can extend the safe time for the fridge by keeping a few water bottles frozen in the freezer and placing them into the food portion of the fridge an hour or two after the power goes out.

2) Yes, that is one of the advantages of the Lithium (LiFePo4) batteries, each battery has a built-in Battery Monitor (BMS) that will control the charging of the battery individually, unlike Lead Acid batteries where the weakest battery controls the health and SOC of the whole battery bank.

With 4 batteries, converting your installation to a Buss Bar system is a good idea.

My experience with the 310 GK indicates that you could easily make it through a night running everything with a 400ah Battery Bank. I do not have the Residential Refrigerator, however I like to keep the coach warm at night and I am confident you would be fine with a 400ah Battery Bank. I would recommend unplugging the coach on one (or two) cold night(s) to test how your coach performs.

I spent a whole month testing out my system running all the 12v devices (including the Furnace) and only charging from my Solar panels (my 120 volt loads [coffee maker and entertainment center] were supplied by the power pedestal). At the time I only had 400ah of usable battery and there was plenty of reserve left in the mornings.

3) I sometimes travel with a Generator, but, that is for those instances where I need Air Conditioning (living in FL, you almost always need it) and have chosen to Boondock. I can run my A/C for a few hours with my battery bank, but in FL you need A/C all day long, so, the Generator fulfills that need.

My Generator runs on Propane which eliminates the need to carry around gasoline. Running on Propane is also very convenient because the Propane tanks will last through the night. If you do decide on a Generator, I would recommend a Propane (or Dual Fuel) powered Generator. You can easily connect the Generator to your existing tanks using an adapter that allows for a quick disconnect to the Generator.

FYI: I carry an extra 20lb Propane tank and keep it in the back of the truck with the Generator. The Generator is orientated in a way that allows me to connect to the Propane tank and run the Generator in the back of the truck (this keeps me from having to load and unload it constantly).

Another option would be to add a DC to DC Converter onto your truck which could be an emergency source of charging your new 400ah battery bank. In your situation I think this would be a better option than a Generator because you could simply hook up to your truck late in the evening for 30 to 40 minutes to top up your battery bank if there was any question about being able to make it through the night. In your situation this would the "Peace of Mind"/"Belts and Suspenders" option that you would rarely use.

Adding two Battle Born batteries to your present system and testing how well they perform in your coach I think you might find yourself to be well equipped enough to boondock for a night or two down the road.

**SolarPoweredRV** · 08-06-2022, 11:56 AM

Originally Posted by Butcher

I like doing things myself. I get that BB is a good product but so is a Maybach. It's too rich for my budget. There are extremely good Lithium batteries on the market that store electrons just as well. If you are sold on BB and nothing will change your mind, good for you. But, with some research and an open mind, I suspect you could almost double your proposed 200ah BB purchase to 400ah alternative [same budget].

You will never have enough power for every situation but a small generator would probably be the easiest. I do not see gasoline ever not being available in my lifetime. Since I do believe you cannot get a good cheap generator [like you can with batteries] I would stick with a small Honda [or other name brand] for the long term outages.

If you live in an area where you must have A/C, I think a larger generator would be needed. Maybe smaller generators daisy chained together.

In the end, there will always be a scenario that will not work but I think a bit more ah and a small generator could get you by for days without A/C.

I have a 3k inverter with 600ah, no generator or solar [yet] and I should be able to last several days. I cannot ever see using a generator for camping because I hate the noise it brings. A large power outage at home, I would be ok with the noise, just not camping.

I look forward to your decision.

Since he already has 2 Battle Born batteries installed, I would recommend staying with the Battle Born batteries for his expanded battery bank.

**Riverbug** · 08-06-2022, 01:59 PM

I'd opt for the smaller generator or DC to DC charger based on your overview of the situation. Each provides the option of charging your existing batteries, which appear to serve your purposes aside from power outages. Given that, in my mind a solution to provide additional charging takes precedence over expending solar or battery capacity for those few times when you need the extra coverage. Of the two options then, considering the infrequency of outages perhaps a DC to DC charger is the way to go. That would alleviate lugging a generator at all, and it would provide the benefit of being able to keep the batteries topped up while traveling if you chose to. But you may have alternator considerations with the DC charger option, although the cost may still be lower or in line with a generator if you chose Honda.

**Second Chance** · 08-06-2022, 03:01 PM

Still reading everything. we're cooking with grandkids this afternoon and getting ready for a picnic by the pool. Will get back to serious stuff late this evening when we get home or in the morning. Thanks for all the input!

Rob

**MoonShadow_1911** · 08-06-2022, 03:02 PM

Originally Posted by Second Chance

Baseline: we ordered our 2020 Solitude with a residential fridge and solar, so it has the stock 300W solar panel, 30 amp Jaboni MPPT controller, ATS, sub-panel, and 2,000W inverter. We put two BB 100Ah LiFePO4 batteries in it on arrival. Our intent was to keep the refrigerator running on travel days and the setup has performed that task very well. We don't boondock.

We've experienced several power outages in the 2-1/2 years since taking delivery of the Solitude. The longest was when a fencing contractor on Aberdeen Proving Ground knocked a transformer off its concrete base and blew a few things up the line. That outage was about four hours - but the sun was out (solar was cranking out the watts) and it was a weekday so the power company got on it immediately (was a bit warm, but we put our recliners under a nice shade tree and read our Kindles). The most recent was last night after a lightening strike on the perimeter of the park. Power was out about 2-1/2 hours before coming back on. At about the two-hour point (10:00PM), the Battle Borns were at 13.2 volts (about 70%?). We were conserving power as much as possible, but it was late in the evening and it was dark (no solar).

Laura has brought up the topic of a generator every time these situations have occurred - and this morning was no different. I want to lay out several scenarios and solicit input. There are a lot of you out there with a better handle on this than I have and I would like to pose some questions (and certainly wouldn't mind if @SolarPoweredRV were to chime in

).

1) Had the power not come back on, I'm not sure the BBs would have kept the fridge running until the sun came up and started hitting the solar panel this morning. Based on the 13.2 volts after approx. two hours, am I right about this or worrying about nothing?

2) Could I add two more BB 100Ah batteries - perhaps replacing the cables with busses - without changing the rest of the setup? I know it would take the converter/charger and the 300 watts of solar longer to recharge them, but would four of the BBs get us all the way through a night with power conservation... even in the winter with the furnace cycling? (And - would there be an issue with adding two of the new series BBs to the two existing BBs?)

3) We're not going to consider an on-board generator installation. It's just not worth it for us. In looking at portable generators, there are several constraints. I'm getting too old to lift a large/heavy generator in and out of the truck bed. The Honda EU2200i is a really nice unit, but would have just enough output to keep the batteries charged, run the fridge, and charge some of our other devices. Even with Easy Starts on the ACs, two of the Hondas ganged would be pushing it for a 15K AC plus the other loads, wouldn't it?

If one of the Hondas would get us over the hump similar to two additional BB batteries, that option would be about $700 cheaper - but I would have to get out the generator and adapters, connect everything, and start the generator... then refuel during the night if there were more than 1/4 load on the generator. If adding two more BBs were to be viable/compatible, I wouldn't have to do all that (worth $700 to me).

If there are other options, I would love to hear about them!

Thanks!

Rob

Howdy, Rob! I'm not @SolarPoweredRV but I think I can give a little insight.

For the battery bank, let's start with the 200 Ah worth of batteries.

Since you didn't specify the size of the inverter you have, I'll use the "standard" 3000 Watt inverter and you stated your residential refrigerator draws 1,625 Watts/24 hours.

Math time!

Refrigerator: 1625 Watts per day = about 0.5888 Ah at 115 VAC - ((1625 / 24)) / 115) = .588768115942. The first calculation gets you Watt hours, which is 67.70833333333. The second part of the calculation gets you Ah for AC power, which comes out to the 0.5888 Ah. Please keep in mind that this is on 115 VAC and we are dealing with a DC power supply with the batteries.

12 volt inverters require approximately one (1) amp of DC input for each 10 Watts of AC output. For the refrigerator running on the inverter, that is and average of 67.7 Watts. 67.7 / 10 = 6.7 amps to run the refrigerator for 1 hour.

Some inverters draw more power than others. To find out your inverter’s power draw, consult the technical specifications section of the inverter manual.

Look for the inverter’s no-load power consumption (watts) or no-load current(mA). You can work out the no-load power consumption (watts) by multiplying the no-load power current by the inverter voltage.

A 1000 watt/ 12V inverter with a no-load power consumption of 7.5W continuously draws 7.5W or 0.63 Ah of the battery capacity even when no appliance is connected.

The no-load power consumption of the inverter mainly depends on:

Inverter efficiency. You should aim for an inverter efficiency of 90% or greater. More efficient inverters have a smaller power draw compared to the less efficient inverters.
Inverter size (watts). Larger size inverters generally have a higher power draw on standby compared to lower wattage inverters.

So in this discussion, theoretically the 200 Ah of BattleBorn batteries should run the refrigerator for 27.3 hours before they are completely dead. This is saying that the batteries will provide a minimum of 8.59 amps for the 27.3 hours. This was calculated from 6.7 Ah for the refrigerator and 1.89 Ah for the inverter for a total of 8.59 Ah.

This is also not taking into consideration the compressor kicking on at approximately 1800 Watts for a brief period of time (milliseconds).

Also, remember that converting DC to AC you loose a minimum of 30% capability. This is true for a battery bank and a generator.

You are also looking at the voltage of the battery bank and not the Watts provided. Remember, the LiFePO4 batteries will give out 100 Ah each until they shutdown at around 10 VDC remaining. So, based on what I am seeing here, 200 Ah should be plenty for running the refrigerator only, over night; even taking into account the minimum power loss of 30% which gives you about 140 Ah instead of 200 Ah. Again, this is for calculation and not actual, your situation will differ.

Hope this helps.

Ciao!

Originally Posted by xrated

Rob....I'm not going to offer anything on the solar aspect of it, as I am pretty much solar illiterate....and have no desire to add anything solar to our trailer. But I do have some knowledge of the LFP battery stuff, as I'm sure you've seen some of my posts about my build recently.

So my battery setup is a 302AH LFP and my fridge is the JC Refrigeration mod to the Norcold 2118. Twin 12V compressors. So when we left Shipshewanna after having the fridge mod done, we had an overnight stay in the Lexington, KY area and my battery was fully charged the next morning when we pulled out for the 6+ hour drive home. From the time I unplugged from shore power in Lexington, till I got home and backed the trailer into the driveway and then plugged in again at my home 50A shore power, was about 6 hrs and 15 minutes...give or take a few. In that period of time (round it out to 6 hours), the Norcold with the twin compressor mod used up just under 6AH for every hour of run time.....so for that trip, I was down 37AH. I had nothing else running in the trailer other than the normal parasitic 12V drain stuff. So doing the math of 6AH times a 24 hour period of 1 full day, the battery would have used roughly 145AH. The twin compressor setup pulls 12.6 amps when BOTH compressors are running...but of course, both compressor don't always run and they cycle on and off during their run time. I don't know how much power your residential fridge will pull from the batteries/inverter, but my example will at least give you a comparison to go by...hopefully.

So the bottom line in all of this is....302AH worth of battery (and you are considering 400AH of battery) provided me with a full day of usage with nothing else running, and still had well over 100AH available. I have mine setup so that I can't discharge it much lower than about 15% SOC....maybe 12% SOC. So 302 times .85 is equal to roughly 257AH available.....and I used 145 in a 24 hour period of time. I figure at worst case scenario, I could run the fridge 40+ hours before needing to recharge the LPFs. I would venture a guess that 400AH of battery would get you through about anything you may encounter....other than something like a major storm where power would be out for days on end. Hope this helps at least a little.

You are also talking about 12 VDC versus 115 VAC. There is a loss when converting DC to AC (as I pointed out above). Straight DC to DC is the best possible situation to get the longest runtime on batteries.

**Seagars** · 08-06-2022, 04:22 PM

You helped me with my issue. Maybe this will help. I have a 3 piece folding hard cover on my f150. What fits perfect under that is a Cummins 4500. I just leave it in place with a 50 ft 30 amp cord. Think you need a 50 but 2 in tandem would do the trick. Adds 75 lbs weight. I can flip up one of the covers and run it in the truck bed. Might help.

**Soundsailor** · 08-07-2022, 09:51 AM

Originally Posted by Second Chance

Baseline: we ordered our 2020 Solitude with a residential fridge and solar, so it has the stock 300W solar panel, 30 amp Jaboni MPPT controller, ATS, sub-panel, and 2,000W inverter. We put two BB 100Ah LiFePO4 batteries in it on arrival. Our intent was to keep the refrigerator running on travel days and the setup has performed that task very well. We don't boondock.

We've experienced several power outages in the 2-1/2 years since taking delivery of the Solitude. The longest was when a fencing contractor on Aberdeen Proving Ground knocked a transformer off its concrete base and blew a few things up the line. That outage was about four hours - but the sun was out (solar was cranking out the watts) and it was a weekday so the power company got on it immediately (was a bit warm, but we put our recliners under a nice shade tree and read our Kindles). The most recent was last night after a lightening strike on the perimeter of the park. Power was out about 2-1/2 hours before coming back on. At about the two-hour point (10:00PM), the Battle Borns were at 13.2 volts (about 70%?). We were conserving power as much as possible, but it was late in the evening and it was dark (no solar).

Laura has brought up the topic of a generator every time these situations have occurred - and this morning was no different. I want to lay out several scenarios and solicit input. There are a lot of you out there with a better handle on this than I have and I would like to pose some questions (and certainly wouldn't mind if @SolarPoweredRV were to chime in

).

1) Had the power not come back on, I'm not sure the BBs would have kept the fridge running until the sun came up and started hitting the solar panel this morning. Based on the 13.2 volts after approx. two hours, am I right about this or worrying about nothing?

2) Could I add two more BB 100Ah batteries - perhaps replacing the cables with busses - without changing the rest of the setup? I know it would take the converter/charger and the 300 watts of solar longer to recharge them, but would four of the BBs get us all the way through a night with power conservation... even in the winter with the furnace cycling? (And - would there be an issue with adding two of the new series BBs to the two existing BBs?)

3) We're not going to consider an on-board generator installation. It's just not worth it for us. In looking at portable generators, there are several constraints. I'm getting too old to lift a large/heavy generator in and out of the truck bed. The Honda EU2200i is a really nice unit, but would have just enough output to keep the batteries charged, run the fridge, and charge some of our other devices. Even with Easy Starts on the ACs, two of the Hondas ganged would be pushing it for a 15K AC plus the other loads, wouldn't it?

If one of the Hondas would get us over the hump similar to two additional BB batteries, that option would be about $700 cheaper - but I would have to get out the generator and adapters, connect everything, and start the generator... then refuel during the night if there were more than 1/4 load on the generator. If adding two more BBs were to be viable/compatible, I wouldn't have to do all that (worth $700 to me).

If there are other options, I would love to hear about them!

Thanks!

Rob

After reading through all of the responses to your post, I think you've already considered your best option. If it were me, I'd go with your idea of 4 BB 100 Ah using a bus bar system. This system supplies your stated needs. If I understood you, you don't boondock, so many of the other off-grid ideas that have been offered would be overkill. The 400 Ah of battery capacity and the 300 watts of solar should handle your needs well, and no need to manage a generator (lift out of the truck, fuel, etc).

**Second Chance** · 08-07-2022, 11:17 AM

OK... after reading and considering all of the input I built a decision grid (can't leave some work habits behind). We considered cost, weight, work (switching over when needed), how well each option would be integrated into our existing system (automation - part of the preceding "work" concept), where the option would mount/store, run time (and how often generators would need to be refueled for those options), whether or not the option would run an AC (a concern of Laura's, but not high up my list for emergency situations), all of the pros and cons we could think of, and the number of votes in the thread (and why) for each option.

After aggregating all of the information from the answers in the thread, we considered these options:

1. Honda EU2200i (sticking with Honda because of reliability and parts/service availability)

2. Two Honda EU2200is (regular and Companion)

3. Honda EU3000IS (bolted down in the back of the truck)

4. Additional Batteries (probably two)

At this time, we have decided to add battery capacity. The reasoning being 1) it will serve the purpose in the vast majority of the situations for which we would want the additional capacity and, 2) we would still have the option of numbers 2 or 3 above should we find that we just can't get by without an AC on a regular basis. We would also have the option of adding another solar panel in the future if/when we see the need for it.

I want to thank everyone for their input. We truly did consider everything that was said with open minds and the discussion was most helpful.

Rob

**xrated** · 08-07-2022, 11:29 AM

There was indeed some very good input for this, and it sounds like you've got a plan now....Congrats Rob, I love it when a plan comes together. I'm sure you'll keep us updated on the implementation and progress.

**acoleman43** · 08-07-2022, 01:42 PM

In my opinion, if you're not boondocking and always plugged in, and all you want is to run your fridge and a few other minor things while power is temporarily down, I would just add a battery or 2. That is the easiest solution and doesn't require any extra effort (like pulling out a generator and hooking it up). The good: Easy, seamless integration. The bad: A temporary fix. Once the batteries are dead, you're done. BB's are not cheap.

Another option is a "portable power station" (Like the Bluetti AC200P/AC300). You can expand batteries if desired. Use it as a standalone unit, or as an auxiliary power source for your trailer. It has built in inverter, AC and DC outputs. You can also connect portable solar panels to charge it when needed. You will want to install soft starts if you plan to use AC with it. The good: flexible - use it as standalone (bring with you on day outing) or as part of your electric system. All-in-one system. The bad: Price. Not as seamless as adding batteries. Does need to be charged because ii is, essentially, a battery pack with built-in inverter/charger.

Portable generator (like Honda 2200i) is a good option as they are "expandable". If one doesn't suit your need you can add another in parallel. A typical 15K AC requires about 1400/1500W to run. For 2 units that is about 3000W. Two of the Hondas will run both AC's, and have a little to spare....but not much. So you turn off 1 AC, use your microwave/coffee pot, then turn AC back on. You will want to install soft starts if you plan to use AC with it. The good: Can be used for multiple days if needed as long as you have fuel. No installation mess...just plug-and-ply. Flexible - can parallel more for mor power output. Cheaper than a portable power station. The bad: When you want to use it, you have to get it out and hook it up...every time. Noisy (well, nosier than a battery or portable power station), require fuel (which costs more money), takes up premium cargo space (space that is easy to get to).

Larger solar system. With this you will still want to add a battery or 2 ($$). The more solar panels will charge the battery bank faster when sunlight is available. When shore power is out, and the sun is out, panels will continue to charge the batteries. The good: works on it's own. "free" energy from sun. Once installed, no effort is needed for it to work. If you have enough panels, will run your system without depleting battery bank (provided enough sun is hitting your panels). The good: Once installed, very seamless. Charges when there's sunlight whether you have shore power or not. Keeps batteries topped off optimized for battery type. The bad: Price....a lot of price. Massive installation required. Panels only work when sun is available.

In my opinion, adding batteries seems like the easiest path for you. If you're concerned about charging times with a larger battery bank, you can install a larger charger that will charge batteries quicker.