Combining the last two posts
I recently purchased a 25 AH LiFePO4 battery and charger..
I can easily pick this thing up with one hand in the manner of a pound of butter (Fingers either side) What's more I can use over 20 of those 25 Amp Hours before the voltage starts to drop significantly
That makes it about the usable capacity of a Group 27 MARINE/deep cycle
The BLF 1225 Weight: 5.8 lbs. (2.6 kg)
A common Group 27 Weight 59. pounds
You can lug a whole lot more AHs with LiFePO4
That said the battery maker does not recommend parallel operation of their batteries.. But some companies make higher capacity models.