Real world boondocking battery life

[esperanto7]

How has the solar been at helping out charging your batteries? Are you still having to use your generator to top them up?

[Soundsailor]

Thank you for your post. I just bought a 2022 21BHE withe the 25 amp solar charge controller and a 165W solar panel on the roof. I plan to get one 100ah lithium battery and up grade the solar but until I do, I am interested to see how fast the poor lead acid battery the dealer gave me will be depleated. I live in Phoenix so a lot of sun but also a lot of heat to make the fridge run more….

@esperanto7, your first step is to come up with a power budget. As the OP did when he listed all of the drains on his battery. Pretty sure you have the 12-volt-only refrigerator, nearly all of the newer coaches are getting these. That is likely to be the majority of your battery needs. In my Reflection, the refrigerator draws generally about 4 to 5 Amps per hour in moderate outside temperatures, I think mine is a bit bigger than yours so you may be 3 to 4 Amps per hour. You'll have other power needs though and you should add those in. Let's say they all add up to 8 Amps. For a day that is 8x24 or 192 Ah. Your 165 watts panel might give you 15 Amps during peak hours (8x15 = 120 Ah). So you'll have to make up the deficit with a robust battery bank. LiFePo4 is definitely the way to go. I'd also suggest more solar. If you can cut the daily deficit you won't need as much battery power. Here in the Northeast, we don't get as much sun. I have 800 Ah of battery power. After a recent 4-day trip with little or no solar, I returned with just 50 Ah left. On a more recent 4-day trip where I did have solar, we had about 400 Ah left when we returned.

[SolarPoweredRV]

Post-trip note. Charged with the truck for an hour each day using my Renogy 20A DC-DC charger through the 7 pin connector. Ended the trip with a 50% charge left on the batteries, so I was averaging 45 Ah per day of electrical usage, and this was being very miserly in my power consumption. Didn't use any of the interior lights (used battery lanterns instead), so this level of consumption was entirely from the fridge, water pump, Compass Connect, and the other small electronics (CO detector, smoke alarm, etc). On the last day, with temperatures in the 80s, the fridge ran non-stop.

With 160 Ah in AGM batteries, I could have gone two and a half days without the charger. I think a small 200W solar installation would have helped tremendously rather than using the truck each day and that will be my next project. I don't see any way to reduce consumption further than what I did.

Very good post trip analysis. I always recommend that you take your camper to a campground with hookups and test out boondocking, then they can learn where their deficiencies are in a safe place where they can plug into shore power if necessary.

[esperanto7]

Thank you for your response! Very good info and daunting to know I need to inject a whole lot more money for decent batteries and more solar. Sort of depressing but it is what it is....

[SolarPoweredRV]

Thank you for your response! Very good info and daunting to know I need to inject a whole lot more money for decent batteries and more solar. Sort of depressing but it is what it is....

It can appear daunting at first, however, you can break it down into smaller chunks which can be less daunting and definitely more wallet friendly. Check out the link below about installing a Solar system in logical phases...

https://www.mygrandrv.com/forum/show...356#post406356

[kengqiuist]

@esperanto7, your first step is to come up with a power budget. As the OP did when he listed all of the drains on his battery. Pretty sure you have the 12-volt-only refrigerator, nearly all of the newer coaches are getting these. That is likely to be the majority of your battery needs. In my Reflection, the refrigerator draws generally about 4 to 5 Amps per hour in moderate outside temperatures, I think mine is a bit bigger than yours so you may be 3 to 4 Amps per hour. You'll have other power needs though and you should add those in. Let's say they all add up to 8 Amps. For a day that is 8x24 or 192 Ah. Your 165 watts panel might give you 15 Amps during peak hours (8x15 = 120 Ah). So you'll have to make up the deficit with a robust battery bank. LiFePo4 is definitely the way to go. I'd also suggest more solar. If you can cut the daily deficit you won't need as much battery power. Here in the Northeast, we don't get as much sun. I have 800 Ah of battery power. After a recent 4-day trip with little or no solar, I returned with just 50 Ah left. On a more recent 4-day trip where I did have solar, we had about 400 Ah left when we returned.

How much solar do you have for the 800ah of batteries?

[Soundsailor]

How much solar do you have for the 800ah of batteries?

Right now I have the 160-watt panel and 50 Amp charge controller that came with the coach. In addition, I've added a Renogy PWM 30 Amp controller to use with an array of portable panels that total 300 watts. We often camp in wooded locations and the portables can be moved around to where there's sun. But frankly, that isn't enough. The next phases of the project include getting more wattage on the roof, 800 watts or more if I can find a way to route the required higher gauge cables. In addition, I need to get my 40-Amp DC to DC charger hooked up.

As well as the solar, I have a 20-Amp lithium-aware charger that I use to top the batteries off from where the stock converter/charger leaves off. When I returned with just 50 Ah left, it took over a day to get back up to 800 Ah. Another future project is to replace the stock converter/charger with one that supports LiFePo4 batteries.

[sirtate]

I've got a 2021 Transcend with the factory solar package. (165W on the roof, 25A controller)
I had the dealer install 2 GC2 (240Ah of FLA) batts at purchase, because i was afraid of the 12V furrion fridge...
This spring I installed an additional 200W of solar on the roof, wired in series with the original panel, using the stock MPPT controller.

Things I've noticed;
1) the stock system will keep up to the fridge as long as ambient temps don't exceed 75F, and those GC2s will last 72hrs of normal use (lights when needed, water pump and radio) under the shade of a forest canopy.
2) when temps get above 75 (23C) the panel will not keep up, and it is a slow downward spiral to flatness.

3) the extra 200w makes all the difference. I leave perishables in the fridge when the trailer is left in storage
the Ice in the freezer has never melted, and I now have to defrost the fridge...


A good batt monitor is key, as is enough storage (120Ah usable)...
The upgrades cost me about $300...

[esperanto7]

Thank you SO much for your real world experience! That is wonderful information!!

[SolarPoweredRV]

Right now I have the 160-watt panel and 50 Amp charge controller that came with the coach. In addition, I've added a Renogy PWM 30 Amp controller to use with an array of portable panels that total 300 watts. We often camp in wooded locations and the portables can be moved around to where there's sun. But frankly, that isn't enough. The next phases of the project include getting more wattage on the roof, 800 watts or more if I can find a way to route the required higher gauge cables. In addition, I need to get my 40-Amp DC to DC charger hooked up.

As well as the solar, I have a 20-Amp lithium-aware charger that I use to top the batteries off from where the stock converter/charger leaves off. When I returned with just 50 Ah left, it took over a day to get back up to 800 Ah. Another future project is to replace the stock converter/charger with one that supports LiFePo4 batteries.

I have a recommendation for you...

Consider using Residential Solar panels instead of the more common Renogy, or Grape, or NewPowa type Solar panels. You will get more Wattage per Dollar as well as more Wattage per square foot from the Residential panels. Additionally, because these panels operate at higher voltages you can use thinner gauge wires to get their power down from the roof. You can also Parallel your panels to increase the voltage which will also allow you to use the thinner gauge wires.

If you do look into Residential Solar panels, make a cardboard mock-up of the panel you are considering installing (be sure to include allowances for any mounting brackets) and get up on the roof to make certain you can arrange the panels on your roof.

Good luck, with a 800ah Lithium battery bank and 800 Watts (hopefully more Watts) of Solar panels you will have yourself a very nice Boondocking Camper.

PS: once you upgrade your Solar system, your camping experience will be much more enjoyable because you will almost never need to worry about running out of power.