Feb-16-2021 04:40 PM
Feb-22-2021 04:41 AM
BFL13 wrote:
You can take a pair of 6s down below 50% without much penalty in number of lifetime cycles, so that would be the first choice IMO. However once that low you can only run low amp draws, not the inverter which will alarm off depending on load and how far down you are in SOC.
LFP (and SiO2 within reason) will be happy to go to a low SOC and still keep the voltage up to allow the inverter to operate.
The real problem is recharging the batts of whatever type when they need it if you only have solar and it is overcast. We have no room for a portable gen in our TC, so that leaves running the truck. Low amp long time recharge not so good.
LFPs are not going to change that. You could still be sitting there with the batts out of AH and no sunshine. You might get an extra overcast day out of it with LFP, but then what? If you have a portable gen, you could have used it two days ago with your pair of 6s.
Seems the LFP option would make sense given the right scenario though.
Feb-21-2021 05:55 AM
Feb-21-2021 04:35 AM
pianotuna wrote:
Steve,
I want my RV to behave as if it were plugged into a 15 amp shore power outlet. That takes a large battery bank, and a way to recharge.
Each to their own! We all love camping.
Feb-20-2021 08:28 AM
Feb-20-2021 08:18 AM
My question is I have one 100 watt solar panel. What is the charge rate like?
Feb-20-2021 08:15 AM
Feb-20-2021 07:49 AM
2Noob4U wrote:BFL13 wrote:
Here is some honest advertising by Relion LFP
"More Usable Capacity 25-50% more capacity than lead-acid equivalent"
The OP wants to camp off grid in a TC for a few days where he runs a few things but not the furnace or bigger inverter loads, so he seems to think one 100AH battery will be enough as long as he has enough solar to keep up. With furnace and the usual things, it takes one battery per day.
He could do his loads with two FLAs and "enough" solar. He is hoping the one LFP will do it, being like 1 and 1/2 batts, which it might with no furnace time.
The money side of things is obvious and up to the OP for what is "worth it" .
EDIT--"enough solar" is the same for either battery bank size. IMO he will need 200w or more and 100w is not enough. On my budget, YMMV, I would get more solar with the money I saved from getting FLA instead of LFP. But I am not the OP!
I do most of my camping in the warm weather months here in Colorado off grid. The furnace has run twice in my Lance 650. I have used a space heater that works more than sufficient in 20 degrees hooked to 30 Amp.
The lead acid battery dies after about 2 days with the 100 watt solar panel. I'm probably not the best steward of making sure the battery amperage and usage stays moderated.
Maybe it's just marketing. I have read that lithium batteries charge faster than lead acid. I also know you can take the lithium batteries down below 50% capacity.
I thought maybe someone was using a 100 watt solar panel and 100 Ah Lithium battery and knew how long/much it would run before needing to run a generator if at all.
Feb-19-2021 04:45 PM
Feb-19-2021 03:44 PM
BFL13 wrote:
Here is some honest advertising by Relion LFP
"More Usable Capacity 25-50% more capacity than lead-acid equivalent"
The OP wants to camp off grid in a TC for a few days where he runs a few things but not the furnace or bigger inverter loads, so he seems to think one 100AH battery will be enough as long as he has enough solar to keep up. With furnace and the usual things, it takes one battery per day.
He could do his loads with two FLAs and "enough" solar. He is hoping the one LFP will do it, being like 1 and 1/2 batts, which it might with no furnace time.
The money side of things is obvious and up to the OP for what is "worth it" .
EDIT--"enough solar" is the same for either battery bank size. IMO he will need 200w or more and 100w is not enough. On my budget, YMMV, I would get more solar with the money I saved from getting FLA instead of LFP. But I am not the OP!
Feb-19-2021 09:38 AM
Feb-19-2021 09:11 AM
Feb-19-2021 09:07 AM
Feb-19-2021 08:48 AM
BFL13 wrote:
There is a difference between what they say you "can" do and what they say you "ought to" do. Here is a BB guy on that--some other things to wade through but it is all there.
https://www.solacity.com/how-to-keep-lifepo4-lithium-ion-batteries-happy/
Feb-19-2021 07:43 AM
Feb-19-2021 07:08 AM
BFL13 wrote:
You will get more usable AH but not twice as many. From a 100AH batt you will get 80 instead of 50 by following the guidelines for each type.
(20-100 vs 50-100)