MINE ARE 249 ah A PIECE on the sticker on top ad they are heavy but they dont seem that heavy i had to pick em up and set them over in the tub under the rear bed ! Im just trying to enlighten all the folks that dont have 20 grand to put in a electrical system that theyre gona use on rare occasions ! I dont know your background but mine has spent 30 plus years 11 mo a year feeding 17 televisions 2 full stereo systems lights fridge freezer microwaves roof airs on 2 agm 4d batteries with up to 12 folks demanding some kind of electrical entertainment so i know this system works hands down day after day and its the same recipe in 1500 to 2k tour busses going up and down the road every day and all the bus builders could use any system they wanted money no object and they still use this one ! So if you want overspend be my guest !
OK, even if they're 250AH, they're still only gonna be rated to 50% DoD (Depth of Discharge) for full life. Most are rated at 80% DoD MAX, but at significantly lower life.
In addition, Lifepo4 have cycle lives in the 3000-5000 range, whereas AGMs are only rated for ~1K cycles MAX with most being 400-800 cycles.
You don't have to spend $20K.. In fact, as mentioned, they're price equivalent with AGM and provide longer life, and more usable power.
So, as mentioned, even BEST case scenario, 500AH of AGM is only gonna get you 400AH of usage... and that's BEST case... and assuming you're OK doing permanent damage to the battery.
That same 400AH of LifePo? Full 400AH is usable with no damage, and would set you back ~$1200.....all the while lasting for 5-10x more charge/discharge cycles.
In fact, speaking of Will Prowse, he did a review on some Black Friday specials...
The only caveat with Lifepo4 vs AGM is BMS in Lifepo4 is usually only rated to 1C, in other words, 100AH battery can deliver around 100A, whereas an AGM can dump more than that. They also don't like being charged below zero, so you need a BMS or charge controller that won't allow charging below freezing, or, what most people do, is keep batteries inside and/or use a battery heater, which doesn't take much power.
As far as my background goes?
Over a decade as an emergency vehicle upfitter, installing lights/sirens/communications, and yes, auxiliary battery systems. Multiple FCC licenses including working on tower site equipment that has, you guessed it, emergency backup systems, with mixed genset/batt backup.
I won't use that as part of my argument though, as it's argumentum ad verecundiam, or 'argument from authority'.. Anything I type is easily backed up with data/facts, so I don't need to bring my background into things.
Up until a couple years ago, you'd be right in going AGM, and in some odd cases, AGM might still be the best option... But now, with cost being the lowest it has ever been, and quality and availability being so high, along with the other benefits I mentioned like weight, cycle life, depth of discharge (usable power), etc. it's a no-brainer to go LiFePo4.
If you're comparing an $800 BattleBorn battery to a $250 AGM battery, well, yeah, duh... But you don't need to spend $800 on a single lithium battery these days.
