Lipo vs "deep cycle" marine battery capacity question

[LanM]

Test data it is then, looks like I'm dancing around that need before any of these projects will get off the ground. I wish that other thread John started would populate with info. It looks like I'll need equipment that can handle 4s and 7s setups for both projects. I'd like to do it affordably. .

Unless you want to start a career testing and analysing cells, you dont need to invest in the full lab quality/pro kit.
You can check, sort, calibrate, and record individual cells for,.. capacity, voltage profiles, DCIR, even thermal stability, ...fairly accurately with simple , cheap kit such as,....a Mmeter, RC lipo logging charger (Imax, Turnigy, etc), maybe a wattmeter. A laptop/tablet/PC with some free data analysis software is also useful, especially if you are doing many cells. Important that the charger has data logging capability.
Assuming you have a laptop, the rest could cost under $100. !
If you chose correctly, the logging charger can serve duty as your 4s pack charger.

That's great, because the info I've been reading is pointing towards $3-400, which is pricey but acceptable long term. Problem is I don't know if I have several hundred duds or not so I'd like to limit my up front expenditures until I know what I have.

 

[john61ct]

I wish that other thread John started would populate with info

You can help, polish up your google-fu. Parse the threads talking about chargers like iCharger 4010-Duo that have good capacity testing,

threads about electronic loads, discharge testing

threads about testing batteries, often list the gear used.

You learn a lot reading old threads, about closely allied topics toos, sometime random gems lead you down new rabbit holes.

Also while you're at it, make a shortlist of expert members you ask to can send some cells to and they do the testing for you.