C Rate!?

[Pneuma]

Hello everyone.

I am in the process of buying my first batteries and I can’t decide. Base on my budgetOn one hand I can get 8x 3.2v fortune cells At 100ah with maximum 6c charge and 2C continues discharge
or
16x 3.2v grade A New BLS cells at 120ah
with recommended .5c charge rate =50ah (max charge at 300ah) and discharge rate of 1C

My inverter is 3kw.

I also want to buy something that is a good investment for future upgrades.
please let me know what you think!

Thank you and prosper

 

[Dzl]

Between the title and the text its not 100% clear what specific advice you are looking for (specific info on c-rates? or general guidance?)

I'll assume a bit of both.

First a general point. You don't give enough info about your planned system or goals to give specific advice.

Some general observations:

1. From what I know, "Fortune" cells are top quality as far as aluminum cased cells go. They are mechanically robust, and have good specs. Fortune branded cells (fortune is a rebrand, not a manufacturer) are generally sold by reputable US sellers, so the risk is somewhat lower in some respects.
2. While some folks on the forum have bought from BLS including Will I believe, I am not super familiar with them, the same cautions and risks that apply to other grey market sellers on aliexpress and alibaba will apply to them.

The answer to which of your two options to choose will largely depend on your needs. Defining how much capacity you need should help with your decision, as will having an idea for what the max current draw will be. To give you one reference point, assuming 12v battery bank, your 3000W inverter may draw up to 300A, more if it has a substantial surge rating.

For our applications (solar, energy storage, etc) high C rate is not usually a primary determining factor since charge and discharge rates for this application will normally be below 1C and will ideally be below 0.5C (for a number of reasons).

A few corrections, your fortune cells would not have a 6C charge rate, they have a 6C pulse charge rate (meaning short bursts of a few seconds). The max continuous discharge rate is 2C (like you said), no max continuous charge rate is stated, but the recommended max continuous charge rate is 0.5C.

All things being equal I would choose the Fortune cells. Since all things are not equal (the no-name BLS cells would be over twice the capacity for the same budget, but carrier greater risks, and be lesser quality), its a tougher decision.

 

[MisterSandals]

I agree with Dzl's sentiments.

I will add that based on your other thread inquiring about 8S2P vs 2P8S battery configuration, as well as your battery choice (100ah) mentioned above, i think you should consider larger cells

There are a LOT of people buying 280ah cells and there is a group buy that seems ongoing. With larger cells, you would be able to get to a large 24v 280ah battery with only 8 cells. This will REALLY make things a lot easier to setup and maintain.