Ian F (Forum Supporter) said:
Antihero (Forum Supporter) said:
The best value batteries is still lead acid really, Trojan makes a bunch of different options that are tried and true
Depends on how much space and weight capacity you have as well as how often you plan to use the system. Lead acid deep cycle batteries can take fewer discharge/recharge cycles than new types. I've seen a few life-of-use calcs where newer tech beats lead acid in cost over time because they don't have to be replaced as often.
I'm saying lead acid don't have their place - I spec them all the time for building UPS systems. But those are situations where the batteries might see a full discharge once or twice over the life of the system, so they are usually just sitting in the cabinet ready to go, rarely seeing a discharge at all other than some regular testing cycles or on the rare occurance the back up generator in the facility fails to start.
I've been off-grid with Trojan lead acid batteries now for 26 years, they are used 24/7 including this exact moment.
They usually last about 7-8 years of 24/7 use before they need replacement.
Curtis73 (Forum Supporter) said:
alfadriver said:
There are quite a few DC-DC systems out there designed for car voltage to LiFePO4 batteries. But the higher the power, the cost goes up a LOT. Also, your battery may limit how fast you can charge it- the one I have installed in my trailer can only be charged at 50A max.
That is a consideration. The DIY 280Ah setup I was thinking of can charge up to 125A but I think my alternator is only 120A. I think if I limit it to 80 or 100A I might have a happier alternator and it will still charge in a few hours.
Is there a cheaper source for prismatic batteries that I may be missing? Alibaba seems to be all over the board with questionable quality. I don't mind paying for good batteries, but I'm also a notorious cheapskate.
We used the CALB prismatic cells and had very good luck with them, they actually improved with later shipments. The range on the vans improved 10% over the 5 years that we ordered that part number.
In reply to Antihero (Forum Supporter) :
FWIW, 8 years of cycling once a day is just under 3000 cycles- which is really good for lead-acid. The LiFePO4 are good for 4000, which is about 3 more years.
And more important for this thread, the equivalent space and weight for lead acid in an RV is a significant difference. Especially these days with development of these cells. A 100 A-Hr LiFePO4 cell weighs a lot less than a 100 AHr lead acid, and you only need one for actual 100ahr instead of 2.
alfadriver said:
In reply to Antihero (Forum Supporter) :
FWIW, 8 years of cycling once a day is just under 3000 cycles- which is really good for lead-acid. The LiFePO4 are good for 4000, which is about 3 more years.
And more important for this thread, the equivalent space and weight for lead acid in an RV is a significant difference. Especially these days with development of these cells. A 100 A-Hr LiFePO4 cell weighs a lot less than a 100 AHr lead acid, and you only need one for actual 100ahr instead of 2.
You aren't wrong about the weight and size, 2 t-105 s would weigh about 120lbs and give you 225ah total and a bit over 100ah usable.
But they are significantly cheaper too, so I still believe they are a better value.
In reply to Antihero (Forum Supporter) :
If price was the only part that one considers for value, sure. They are cheaper.
