Boondocking with Furrion 12vDC

[jbt816]

I've been searching and reading the forums, but have not found the exact answer to my question.

My current setup is a 2023 Reflection 303RLS with the stock 370w solar panels. I have two identical batteries installed by the dealer: Interstate SRM-24. 81AH each (so I have 162 AH). We have the Furrion 12vDC fridge (16cuft).

What I would like to know is if anyone has any practical experience boondocking with this setup? I know I could upgrade to lithium batteries or add more solar or even buy a generator, but I want to know how many hours (roughly) to expect. I understand there are multiple variables.

In the interest of transparency, we are not BIG boondockers but have occasionally gone off grid for two days at a time....generally near Vail, Colorado....generally in August.

My concern is really limited to the refrigerator.

Thanks,
Bruce

[TucsonJim]

Hi Bruce,

I have a Norcold 12VDC reefer, which has very similar current draw to the Furrion. When I ran tests on my unit, I typically consumed about 70-75 amp hours per day.

Remember, your two Interstate batteries will provide you with 81 amp hours of useable power per day. You normally don't want to deplete a lead acid battery below 50% state of charge in order to get the maximum life out of it.

Typically, you can obtain 60-80% of your solar panel capacity in real world conditions. This is due to clouds, shading, angle if incidence of the sun's rays, etc. So you can likely see 220 to 300 watts maximum from your panels at any given time.

In my opinion, you'd probably be okay for a day or two of boondocking. Over time, I think your battery bank will slowly be depleted until you need to run a generator or plug into shore power so the converter can help you get back to full charge. But I wouldn't hesitate to take it out for a field trial.

Jim

[howson]

I've been searching and reading the forums, but have not found the exact answer to my question.

My current setup is a 2023 Reflection 303RLS with the stock 370w solar panels. I have two identical batteries installed by the dealer: Interstate SRM-24. 81AH each (so I have 162 AH). We have the Furrion 12vDC fridge (16cuft).

What I would like to know is if anyone has any practical experience boondocking with this setup? I know I could upgrade to lithium batteries or add more solar or even buy a generator, but I want to know how many hours (roughly) to expect. I understand there are multiple variables.

In the interest of transparency, we are not BIG boondockers but have occasionally gone off grid for two days at a time....generally near Vail, Colorado....generally in August.

My concern is really limited to the refrigerator.

Thanks,
Bruce

Bruce,
Does your 303RLS have the Furrion Battery Monitor, and if it does, was it calibrated to match the capacity of the battery bank? Knowing how to use (and closely monitoring) the battery monitor would be wise as you learn the capabilities of your system to avoid running down the battery bank inadvertently.

Howard

[COReflection]

I've been searching and reading the forums, but have not found the exact answer to my question.

My current setup is a 2023 Reflection 303RLS with the stock 370w solar panels. I have two identical batteries installed by the dealer: Interstate SRM-24. 81AH each (so I have 162 AH). We have the Furrion 12vDC fridge (16cuft).

What I would like to know is if anyone has any practical experience boondocking with this setup? I know I could upgrade to lithium batteries or add more solar or even buy a generator, but I want to know how many hours (roughly) to expect. I understand there are multiple variables.

In the interest of transparency, we are not BIG boondockers but have occasionally gone off grid for two days at a time....generally near Vail, Colorado....generally in August.

My concern is really limited to the refrigerator.

Thanks,
Bruce

We just purchased our new GD 303RLS last Oct and I have been working on it all winter providing upgrades and such getting it ready for May camping season to start. When I picked it up from Kansas City and drove back to CO....the camper was also equipped with two Interstate deep cell batteries and then the one Furrion 165w solar panel. The dealer told me it had been on the lot unplugged for a few weeks while waiting to be sold. When I arrived to check it out...it was unplugged and the fridge was operating fine on the batteries and solar. I checked it with a meter and the batteries went down pretty low at night but then recharged to about 90% during the day. I decided that would not work for me but I was really trying to baseline the battery draw for my math on the new upgrades and the 12v fridge. Since we always boondock for 3-5 days at a time....I wanted more than enough capacity to not worry about the batteries and be able to watch a movies once and awhile without our generator. I did a huge upgrade and moved up to 565w of solar and 560Ah of lithium batteries and believe I will be fine now but we will see. Since we camp mostly in the woods...I am counting on low return from the solar. I would suggest running some tests in a field as Jim noted or in your driveway so that you can baseline how your system works and plan accordingly before getting stuck somewhere with low power. If you are boondocking in the trees...then your solar panel energy return will obviously be lower.

I totally agree with Howard....first thing is to install and/or calibrate an accurate meter to see what's really going on with your batteries and the energy going in/out.

[Country Campers]

Another thing to keep in mind is other 12 v dc usage, lights, furnace, vent fan, water heater, water pump, and others. These all will draw the battery down. I did a battery upgrade to Lithium a couple years ago and also changed to the Furrion 12 v dc fridge, here is the thread with some usage numbers Replacing Lead Acid Battery with Lithium - Grand Design Owners Forums (gdrvowners.com). This is just some information on what I experienced and I did not conserve at all.

Brian

[jbt816]

Bruce,
Does your 303RLS have the Furrion Battery Monitor, and if it does, was it calibrated to match the capacity of the battery bank? Knowing how to use (and closely monitoring) the battery monitor would be wise as you learn the capabilities of your system to avoid running down the battery bank inadvertently.

Howard

By Furrion battery monitor, do you mean this (see pic)? Or something fancier?

I do not know if it is calibrated but I doubt it. My friend also bought an identical unit from the same dealer but in a different city and only received one battery.

[Country Campers]

Yes that is the Furrion monitor. It needs to be set to your battery capacity, 1/2 the total amount of ah. There should be a manual in your paper work to set this up.

Brian

[COReflection]

Another thing to keep in mind is other 12 v dc usage, lights, furnace, vent fan, water heater, water pump, and others. These all will draw the battery down. I did a battery upgrade to Lithium a couple years ago and also changed to the Furrion 12 v dc fridge, here is the thread with some usage numbers Replacing Lead Acid Battery with Lithium - Grand Design Owners Forums (gdrvowners.com). This is just some information on what I experienced and I did not conserve at all.

Brian

Great post on your upgrades---Brian. Thanks for sharing.

Dave

[Cate&Rob]

My friend also bought an identical unit from the same dealer but in a different city and only received one battery.

Batteries are installed by the dealer, not by Grand Design . . . so it is quite likely that there will be differences in number, size and quality of batteries in otherwise similar RVs.

Rob

[jbt816]

Yes that is the Furrion monitor. It needs to be set to your battery capacity, 1/2 the total amount of ah. There should be a manual in your paper work to set this up.

Brian

there are some basic instructions in the grand design owners manual. I do not have a separate booklet of instructions for the monitor itself.

I did find online that if I press and hold the percentage button for three seconds, it will reset/calibrate. But I see nowhere that I am able to input that these particular batteries are 81 amp hours.

[ncitro]

there are some basic instructions in the grand design owners manual. I do not have a separate booklet of instructions for the monitor itself.

I did find online that if I press and hold the percentage button for three seconds, it will reset/calibrate. But I see nowhere that I am able to input that these particular batteries are 81 amp hours.

The manual is in post 3 of this thread:

https://gdrvowners.com/forum/operati...r-instructions

[jbt816]

I found these instructions online (finally). My question to you all is: When it says "discharge the battery bank.......DO NOT discharge battery below 10.5 volts." What voltage would you recommend I do discharge it to?

Discharge the battery bank by turning loads on in your RV and
disconnecting any charging equipment. DO NOT discharge battery
below 10.5 volts. Once discharged, begin the following:
1. Press to display battery capacity %.
2. Press and Hold for 3 seconds, this will calibrate the meter
to indicate the battery is at 0% capacity (empty).
3. Press to display Ah battery capacity, then press for 3
seconds to enter setting mode.
4. Press to increase Ah value to the max or a value reasonably
greater than the capacity of the battery bank. Press to set
the value.
5. Charge the battery bank completely until the Ah or % capacity
stops increasing. Charging may take over 24hrs to stabilize.
6. Repeat step 3, 4, but instead set capacity to the Ah value
indicated by the meter from fully charging the battery bank.
(This is the true capacity of the battery bank.)

[howson]

there are some basic instructions in the grand design owners manual. I do not have a separate booklet of instructions for the monitor itself.

I did find online that if I press and hold the percentage button for three seconds, it will reset/calibrate. But I see nowhere that I am able to input that these particular batteries are 81 amp hours.

Just a note that what you read in the instructions won't mention setting the value to 1/2 of your battery bank's aH capacity.

There's two schools of thought on this issue. One camp says set it to 1/2 of the aH capacity (when dealing with lead acid batteries) so when the meter reads "0" the bank is in reality at 50%, or the maximum ideal depletion before recharging. (There's even controversy on that topic but we'll leave that topic alone.)

The other "camp" says set the monitor to the full aH capacity of the battery bank, and then it's up to the user to know that when the monitor shows 50% they are at the point where the bank should not be depleted any further before recharging.

What I don't know is if the monitor will show a negative percentage. In other words, if the monitor is set to 1/2 of the aH capacity and the battery voltage dips to what in reality is a 40% state of charge (SoC), will the monitor shows a -10% SoC? Even if it does that could be confusing to some owners.

Hope that rambling makes some sense...no right or wrong either way, just a choice for you to make.

Howard

[jbt816]

The manual is in post 3 of this thread:

https://gdrvowners.com/forum/operati...r-instructions

Actually, that is not the battery monitor I have. thanks though

[howson]

I found these instructions online (finally). My question to you all is: When it says "discharge the battery bank.......DO NOT discharge battery below 10.5 volts." What voltage would you recommend I do discharge it to?

Discharge the battery bank by turning loads on in your RV and
disconnecting any charging equipment. DO NOT discharge battery
below 10.5 volts. Once discharged, begin the following:
1. Press to display battery capacity %.
2. Press and Hold for 3 seconds, this will calibrate the meter
to indicate the battery is at 0% capacity (empty).
3. Press to display Ah battery capacity, then press for 3
seconds to enter setting mode.
4. Press to increase Ah value to the max or a value reasonably
greater than the capacity of the battery bank. Press to set
the value.
5. Charge the battery bank completely until the Ah or % capacity
stops increasing. Charging may take over 24hrs to stabilize.
6. Repeat step 3, 4, but instead set capacity to the Ah value
indicated by the meter from fully charging the battery bank.
(This is the true capacity of the battery bank.)

Those instructions from Furrion are (IMO) idiotic. No way I'd discharge a lead acid down that far on purpose.

The Linklite instructions (I'm sure it's the same unit with a different nameplate) are what I'd do. In short, set the battery capacity, charge the batteries to their full capacity, and then synchronize the monitor.

See https://gdrvowners.com/forum/operati...0235#post80235

Howard