Interstate Batts & our RV

[Scramjet]

Here is the most definitive study I have found on the usage and cost of lithium vs lead acid batteries in RV’s. I have an engineering background so I like this kind of science experiment!

https://youtu.be/iy3hga_P5YY

In summary you get the most power per dollar using cheap 6v flooded lead acid batteries.

You get the lowest lifetime cost per dollar using lithium.

Like I said before, I like lithium in the long run. I am more concerned with pin weight so lithium has a double benefit in that respect.

Brian

[boyscout]

Here is the most definitive study I have found on the usage and cost of lithium vs lead acid batteries in RV’s. I have an engineering background so I like this kind of science experiment!

https://youtu.be/iy3hga_P5YY

In summary you get the most power per dollar using cheap 6v flooded lead acid batteries.

You get the lowest lifetime cost per dollar using lithium.

Like I said before, I like lithium in the long run. I am more concerned with pin weight so lithium has a double benefit in that respect.

I see that you're in Ohio. How do you manage the fact that most lithium batteries can't be charged in cold weather?

(If your answer is, "I go south in the winter" please don't rub it in the face of this Covid-imprisoned Canadian! )

[Scramjet]

I see that you're in Ohio. How do you manage the fact that most lithium batteries can't be charged in cold weather?

(If your answer is, "I go south in the winter" please don't rub it in the face of this Covid-imprisoned Canadian! )

Boyscout,

I have not solved that problem yet. We are still using FLA batteries. I am thinking a 12v heat mat with a thermostatic controller set to about 40 degrees F (maybe 5 degrees C) inside an insulated battery box. Kind of a poor man’s Battle Born heated battery. The other option is to disconnect the solar panels from the charge controller and only plug in the rig when it is above freezing.

I don’t think mounting in the heated basement compartment of the RV will work for me since I am not full-time and do not want to heat the rig full time. I do keep the outdoor sending unit for the weather station in the compartment space to track the temperature in there.

We did try going south this winter for the first time since I retired and that worked well too😀😀😀

Brian

[rootusrootus]

Here is the most definitive study I have found on the usage and cost of lithium vs lead acid batteries in RV’s. I have an engineering background so I like this kind of science experiment!

https://youtu.be/iy3hga_P5YY

In summary you get the most power per dollar using cheap 6v flooded lead acid batteries.

You get the lowest lifetime cost per dollar using lithium.

Like I said before, I like lithium in the long run. I am more concerned with pin weight so lithium has a double benefit in that respect.

Brian

Also, there is a pretty wide range of price/kWh with lithium batteries right now, with every expectation that it will go lower.

By my math, at current prices,

Battle Born is $750/kWh, 25.8 pounds/kWh (assuming 100Ah battery, the 270Ah costs more)
Ampere Time is $354/kWh, 19.2 pounds/kWh (assuming 200Ah battery, the 100Ah & 300Ah models cost more)
DIY LFP done right is $200/kWh, ~17 pounds/kWh (4S 270Ah cells)
Costco Interstate GC2 is $157/kWh, 92 pounds/kWh (two batteries, 220Ah@20hr each, 50% usable).

There is no 100% right answer, really. Depends on your individual use case. Although, as the price of LFP continues to drop, won't be long until there aren't any advantages at all to sticking with the lead bricks.

When I finish up my second battery, I will have 540Ah on the tongue of my trailer, weighing in around 100 pounds total, maybe a bit more. To do the same with FLA, I would have to spend a thousand bucks on cheap GC2s and they aren't going on the tongue, they'd have to be in the front compartment because there would be 10 of the suckers. Just about 600 pounds of lead .

[Scramjet]

Also, there is a pretty wide range of price/kWh with lithium batteries right now, with every expectation that it will go lower.

By my math, at current prices,

Battle Born is $750/kWh, 25.8 pounds/kWh (assuming 100Ah battery, the 270Ah costs more)
Ampere Time is $354/kWh, 19.2 pounds/kWh (assuming 200Ah battery, the 100Ah & 300Ah models cost more)
DIY LFP done right is $200/kWh, ~17 pounds/kWh (4S 270Ah cells)
Costco Interstate GC2 is $157/kWh, 92 pounds/kWh (two batteries, 220Ah@20hr each, 50% usable).

There is no 100% right answer, really. Depends on your individual use case. Although, as the price of LFP continues to drop, won't be long until there aren't any advantages at all to sticking with the lead bricks.

When I finish up my second battery, I will have 540Ah on the tongue of my trailer, weighing in around 100 pounds total, maybe a bit more. To do the same with FLA, I would have to spend a thousand bucks on cheap GC2s and they aren't going on the tongue, they'd have to be in the front compartment because there would be 10 of the suckers. Just about 600 pounds of lead .

Rootus,

Good summary! Exciting how this battery technology keeps getting better and cheaper. It is kind of an eye opener when one of the more expensive lithium alternatives is still lower in overall lifetime cost. Granted Battle Born is one of the best.

Brian

[Rgpracer]

Outstanding Sir.
Thanks

Rootus,

Good summary! Exciting how this battery technology keeps getting better and cheaper. It is kind of an eye opener when one of the more expensive lithium alternatives is still lower in overall lifetime cost. Granted Battle Born is one of the best.

Brian

[fez111]

-About a week before we came back to Michigan from Florida last spring one of my two tandem 12V Interstate batteries had a literal meltdown. I went into the front boot to get something and could smell acid burning. My 3-year old battery was hotter than you-know-what, and boiling! Being very careful to disconnect ALL DC loads BEFORE disconnecting the bad battery (don't really need or want an explosion) I pulled it out and let it sit for the two weeks before we moved back north.

I spent two nights online comparing prices for the high-end gas mat and other battery types and interstates, but one forum I read made it very clear. The biggest deep-cycle battery that Walmart sells is 850 cold cranking amps, but still around $100. For what a gas mat or other battery costs I can buy 4 Walmart batteries that should each last a few years. I check the levels at least twice per year. We just could not justify the price of buying an really expensive battery. We found after a storm that our Solitude is able to run the Fridge, gas hot water tank (both use battery power) and with limited light usage we made 36 hours before the fridge started beeping. Two batteries should double that. I have room for a third battery in my box but I am afraid the converter wouldn't like the current required to charge three flat batteries... Looking for a bigger capacity converter!