First time poster seeking advice

[HH2]

I bought a Zooms 100ah lithium iron phosphate battery less than a year ago just to have quick and easy access to small amounts of electricity during a power outage without having to run the generator all the time. Since then, I decided I want about 2 to 6 times the 100ah of capacity I currently have. I’d appreciate any advice anyone wants to give on whether I could add additional 100ah batteries in parallel gradually over time or whether I should wait and buy higher capacity all new batteries all at one time. Ideas about this seem to be mixed. Zooms (now Redodo) recommends that batteries connected in parallel be purchased within one month of each other. Battleborn recommends that batteries connected in parallel be purchased within two year of each other. What’s the consequences of buying similar 100ah batteries gradually over time and connecting batteries in parallel that weren’t bought at the same time? I appreciate any thoughts and advice on this anyone may have.

 

[obd.tech]

Fully charge both batteries & then link in parallel.
Andy on the off grid garage did a YT about this,

 

[MrThisIsME]

If it were me, I would just continue adding the same Zooms.

 

[HH2]

Thank you both for your input. I’ll search for the YT video. It sounds interesting.

 

[Kornbread]

Generally, it is better to add batteries with as similar abilities as possible, which often suggests buying them all at once in order to avoid things like age and manu tolerances, but batteries are expensive, and if you are like a lot of the people found on a diy forum, and here to not only learn but to save a little $ in the process, well, we tend to save our pennies and add to the system as $ allows.

 

[HH2]

I appreciate everyone’s advice. It makes sense that buying batteries of the same age would be preferred. I was thinking though that even batteries exactly the same age would wear at different rates over time when more than two are connected in parallel because (if I understand correctly) they would charge and discharge at slightly different rates. The exception might be when hooking batteries up in parallel to a bus bar with equal length conducters. This might at least minimize the differences in wear on the batteries. Is my thinking correct on this? I’m inexperienced, but think I’m gaining some understanding of this mostly through Will’s and others’ YouTube videos.