Largest Lithium AMP Hour Battery - 2023 Arctic Fox 865

[skanj0]

My wife and I are soon picking up a 2023 Arctic Fox 865 to replace our trusty 2005 Lance 845. We almost exclusively boondock so I am gathering all the pieces I need to add ~500 watts of solar on the roof, victron equipment, and now trying to figure out how large of lithium battery I can get into the Arctic Fox battery compartment. I’m fine with removing the Northwood sliding battery tray to accomplish this.

Does anyone know the dimensions of a late model Arctic Fox 865 battery compartment? Can I get a 300 amp/hr lithium battery in there? We are buying our camper 3 states away and unfortunately dont have access to an 865 on a lot anywhere near us.

Thanks for the help.

Update: Going back and adding the oem Arctic Fox 865 battery box measurements for others that may want them. The limiting factor is the battery compartment door which is smaller than the inside of the battery box.

Battery Box:
Once sliding battery tray is removed, inside dimensions of battery box are: 17” deep by 17” wide by 12.5” tall.

Battery compartment door opening:
14.75” wide by 11.375” tall by 1.25” deep.

[Grit_dog]

Fwiw, rough roads don’t blow out LP pilot lights. Unless you happen to be going really really fast on them…

[StirCrazy]

skanj0 wrote:
Thanks for all of the responses. My truck is already setupfor high amperage charging and has a DC Power 275 amp alternator with 2 ga. copper wires run through a circuit breaker and continuous duty forklift solenoid to the front passenger corner of the truck bed. Planning connect this to the new camper as well when I add solar, victron charger/inverter, and larger wires to the battery bank.

Northwood is currently not offering a 3 way fridge in their truck campers due to manufacturer supply issues. Therefore I want my setup to be able to run the fridge in AC mode using the solar & truck alternator while going down the road. In the past I have tried to use propane going down the road and it would not stay lit in our Lance. It may be since we go offroad in the national forests and often its a fairly rough ride.

I have my eye on these particular https://www.sunfunkits.com/category/3/pre-built-batteriesbatteries if they will fit (option 1: 300 ah and option 2: 275 ah):

here is another option for the batteries. these have been discussed, tested, and taken apart by will Prowse and Showen to be decent batteries.

load testing

tear down

If you are going to run a 110 fridge, when you switch to Lithium I recommend a DC-to-DC converter. if your already set up for high amperage out of your alternator you could get a larger one and you just have to make sure total draw won't tax your alternator.

Renogy makes a 30 amp one and a 50 amp one that are pretty decent.

You should be able to run your fridge. If it's a newer one it will auto relight when it needs to, unlike my 1991 camper Haha.

and finally, I am a big proponent of running as much solar as you can. If you can get two panels on there and have the space to run two 300's I would. This would also reduce the load off your truck alternator during the day while traveling.

[pianotuna]

Golden_HVAC,

The best way to limit current may be a dc to DC converter (or charger). That allows for optimization of the charging voltage, too.

When I had 875 amp-hours of lead acid batteries I'd observe over 70 amps of charging. That was not so good for my oem alternator, though it did not fail.

I do have a dc to DC unit installed now--for other reasons, but it does limit charging current on the output side to 20 amps @ 14.7 volts. There are dip switches to set the voltage.

[greenno]

Yeah it does run the ac when we need it. Got a soft start so it will run on high or lo through the inverter I have.
Used to carry a 2.2kw genny around with us for the micro, coffee maker or ac but this setup handles everything just fine.
As long as I can get decent sun I can also recharge my e-bike battery after a ride too.

My 2way frig runs fine on propane. If it’s windy on the road a couple of times the pilot went out. Just turn it off then on and it relights and runs fine.
For my usage no way would I run my unit on 12vdc, if it ain’t broke…..

[3_tons]

greenno wrote:
I have a 2019 AF990 and it will hold (2) group 29 L/A battery's as stated above.
I removed mine and added 560ahr of Lifepo4 in the same compartment that includes a 200a BMS Fuse block and Pos/Neg terminal boards for all connections. Even have a 1/4" foam box built around the battery's to help insulate them from cold weather and for protection as well.
Got 510w of solar on my roof also and even have a 3k PSW Inverter mounted back in the generator compartment for any 120v loads we need.

I could of removed my sliding tray or even Modified/Cut out a portion of the battery box but didn't need to as it all fit fine.
Don't really have to worry about any gases with Lithium batteries so they don't necessarily need to be in a closed compartment.

We go off grid quite a bit and never really have to worry about having availible power.

Congrats on your new rig.

Kinda sounds like a LFP home-brew system rather than drop-in I suppose…Just curious, with so much power, do you use it to run your air conditioner?? :@

3 tons

[skanj0]

Thanks for all of the responses. My truck is already setupfor high amperage charging and has a DC Power 275 amp alternator with 2 ga. copper wires run through a circuit breaker and continuous duty forklift solenoid to the front passenger corner of the truck bed. Planning connect this to the new camper as well when I add solar, victron charger/inverter, and larger wires to the battery bank.

Northwood is currently not offering a 3 way fridge in their truck campers due to manufacturer supply issues. Therefore I want my setup to be able to run the fridge in AC mode using the solar & truck alternator while going down the road. In the past I have tried to use propane going down the road and it would not stay lit in our Lance. It may be since we go offroad in the national forests and often its a fairly rough ride.

I have my eye on these particular https://www.sunfunkits.com/category/3/pre-built-batteriesbatteries if they will fit (option 1: 300 ah and option 2: 275 ah):

[StirCrazy]

Golden_HVAC wrote:
I recently learned that a Lithium battery can accept power at greater than 100 amps. So the RV in question had a limiting device on it to restrict the amperage going into the Lithium battery pack, so not to melt the alternator. In your case, you might have a 20 amp circuit breaker feeding the camper +12 circuit, and that fuse would quickly trip if the truck is 14 volts and the battery 12.5. A auto reset circuit breaker might help, or run a second power line that is sized at 30 amps and a auto reset circuit breaker that size?

it doesn't matter what it can accept, it is not going to force a 30 amp controller or a 40 amp controler to put out more power than they are designed to. The alternator one is a wife's tail, and the video was rigged to be able to do it as a sales gimmick. in reality you will never get enough power through the small charging wires to ever hurt the alternator. The limiting device was most likely a DC to DC charger which will throttle the output from the alternator like you have said but will also provide the proper charge profile to the LiFePO4 battery while you are traveling. this is handy as you can limit how fast it will be able to charge to keep the load low on your alternator while still running larger charge cables to have a lower voltage drop.

the real thing is that they can accept more charge and they will charge more efficiently than a lead acid battery, so if you limit the charge to 30 amps to make sure the load on your alternator is below 50% when everything is running, the LiFePO4 battery will reach a full charge faster. as for 500 watts of panels that's about what I am shooting at especial if you use 120v stuff. The price of panels is dirt cheap, and I set up my systems to be able to recover from the previous night's usage by noon on a nice day. Right now, I have 325watts and I am adding a second one when I add the inverter.

by oversizing a bit, it just makes it, so my batteries stay at 100% from noonish until it gets dark as the panels supply the daytime usage even if I am running the furnace and stuff. but what it is really good at is if I get a few days of bad weather and no charging then when the sun does come out the capability is there to get me back to 100% in one day.

[greenno]

I have a 2019 AF990 and it will hold (2) group 29 L/A battery's as stated above.
I removed mine and added 560ahr of Lifepo4 in the same compartment that includes a 200a BMS Fuse block and Pos/Neg terminal boards for all connections. Even have a 1/4" foam box built around the battery's to help insulate them from cold weather and for protection as well.
Got 510w of solar on my roof also and even have a 3k PSW Inverter mounted back in the generator compartment for any 120v loads we need.

I could of removed my sliding tray or even Modified/Cut out a portion of the battery box but didn't need to as it all fit fine.
Don't really have to worry about any gases with Lithium batteries so they don't necessarily need to be in a closed compartment.

We go off grid quite a bit and never really have to worry about having availible power.

Congrats on your new rig.

[Golden_HVAC]

I recently learned that a Lithium battery can accept power at greater than 100 amps. So the RV in question had a limiting device on it to restrict the amperage going into the Lithium battery pack, so not to melt the alternator. In your case, you might have a 20 amp circuit breaker feeding the camper +12 circuit, and that fuse would quickly trip if the truck is 14 volts and the battery 12.5. A auto reset circuit breaker might help, or run a second power line that is sized at 30 amps and a auto reset circuit breaker that size?

With 500 watts of solar, that is about 2,500 watts per day. So a 100 AH battery at 12 volts is 1,200 watts. 2 batteries would seem enough to save all of 1 day power, and then some. I used to have a 400 watt solar system on a 97 Bounder and 400 AH of 12 volt batteries. Of course that battery should only be depleted by 50%, something the lithium does not care about. I was never without power, especially after switching from the tube TV to a flat screen that used much less power.

Personally I think you will be fine with only 200 AH, and being so expensive, buying more battery than you will ever use is just expensive.

[pianotuna]

Battery compartment is sized for 2 group 29 batteries.

29NF has dimensions of 13 x 5.5 x 8.93 inches, while the 29H battery measures 13.1 x 6.7 x 9.1 inches

[NatParkJunkie]

I got a 200 amp hour SOK battery, have been very happy with it. Eventually I'd like to get a second one but need to do some careful measuring first too.

[pianotuna]

skanj0,

Ask the seller to measure the compartment?