joe_julie81
Oct 26, 2017Explorer
AGM batteries?
Is it imperative to have AGM batteries with a solar set-up? Why? Could you not just use 2 6v batteries (not AGM's)? Do they last longer? How much and are they really worth the price difference?
HMS Beagle wrote:
It isn't clear than lithium batteries will get a lot cheaper with time - they've been out there for a number of years without much price movement. More likely is a better chemistry will be introduced, such as carbon air or aluminum air.
cewillis wrote:
Depth of discharge was explicitly including in my calculation by using available AH instead of rated AH.
Agree about the price being better in the future.
cewillis wrote:DWeikert wrote:
The only other thing your missing is the practical depth of discharge (DOD) for an AGM battery is 50%. For Lithium-iron-phosphate, it's 80% DOD. Thus, to get the same usable energy the AGM needs roughly double the Ah rating of the lithium.
lithium-ion vs agm
That said, I just installed 2 new GRP-31 AGM's in my camper. I'm thinking by the time these need replaced the lithium price point will be much more attractive.
Depth of discharge was explicitly including in my calculation by using available AH instead of rated AH.
Agree about the price being better in the future.
DWeikert wrote:
The only other thing your missing is the practical depth of discharge (DOD) for an AGM battery is 50%. For Lithium-iron-phosphate, it's 80% DOD. Thus, to get the same usable energy the AGM needs roughly double the Ah rating of the lithium.
lithium-ion vs agm
That said, I just installed 2 new GRP-31 AGM's in my camper. I'm thinking by the time these need replaced the lithium price point will be much more attractive.
cewillis wrote:work2much wrote:
My cost per 100Ah battery delivered with bus bars is $ 550. Fo me at least this takes AGM and wet cell batteries out of the game for what I was looking for.
Sounds like good work on your part, and I'm certainly not going to argue the value of lithium batteries -- at some point.
But just for reference, in my case -- 4 x 140AH@12v for less than $1000.
Let's say that's 280AH available for $1000.
That's $3.57/AH. Your's -- $550/100 = $5.5/AH
Unless I'm missing something.
Cost comparison only -- I bet mine weigh a good deal more at 375 lbs.
nightshift wrote:
Has anyone installed these carbon foam units in their rig? Expensive but if you can discharge them 80% as claimed, that's impressive.
cewillis wrote:work2much wrote:
My cost per 100Ah battery delivered with bus bars is $ 550. Fo me at least this takes AGM and wet cell batteries out of the game for what I was looking for.
Sounds like good work on your part, and I'm certainly not going to argue the value of lithium batteries -- at some point.
But just for reference, in my case -- 4 x 140AH@12v for less than $1000.
Let's say that's 280AH available for $1000.
That's $3.57/AH. Your's -- $550/100 = $5.5/AH
Unless I'm missing something.
Cost comparison only -- I bet mine weigh a good deal more at 375 lbs.