[Spere]

First time post - hoping to check my thought process.

Just took delivery of a number of GBS-LFMP100AH. The project is underway, but the cells will be sitting for up to 3 months.

Once installed, the system will use the Elite BMS and appropriate dedicated charger.

Until then, I'm looking for a charger to bridge the project until the system is installed and all setup; the single task of the charger would be to set the individual (3.2 V) cells to a good storage voltage from their shipping voltages / SOC.

I'm aiming for ~50% SOC, thus (as I read it) about 3.3 volts after initial settle. [Cell charging and discharging curves are attached].

My first option would be to purchase a benchtop powersupply - as I can always use another - and perform a manual charge on each "3.2 V" cell. This being a candidate: Eventek-KPS3010D

Another option would be to get a Hobby/RC charger, such as: Turnigy Accucel-6

I'm hoping that wiser / more experienced minds will confirm that while the manual charging method may be tedious, it is a reasonable approach. I'd rather buy the powersupply that will get used relatively frequently than a charger that will mostly sit.

The method need not be fast, but just get the job done in an reasonable way. I'm certainly open to other options.

Thanks!

 

[Duncan]

Why would a good "storage SOC" be different from a "shipping SOC"?

It seems to me that you want a SOC that is somewhere near the middle for both but as long as you avoid the extremes anything in the middle half would be fine

The only reason that I would change from the shipping SOC would be if I wanted to test the cells while still under warranty
If that is what you want to do then you need a charger/discharger like the powerlab6

https://www.amainhobbies.com/revole..._1g5Of4tBPoOXq1Mknyg8X4Y2OevEEuEaAqP7EALw_wcB

 

[Spere]

Thanks for the reply Duncan.

Per the shipping regulations here (USA & Canada), the cells can be shipped with a max SOC of 30%.

For Storage, my understanding is that a 50-60% SOC is best practices.

 

[Duncan]

Hi
I think you are worrying too much

Check the voltage now - and check again in a couple of weeks

In my experience it will not change - they will be OK for months

If one cell or a couple does self discharge then they were knackered already - and you would not have been able to save them no matter what you did

Definitely worth checking their voltage, the main thing that you are looking for is that they are all the same

 

[Spere]

Thanks Duncan,

I have been known to fret

I checked the cells upon receipt, and again just now (a week later). All cells are at 3.30 volts for both readings.

This all looks good from my understanding.

-- Thanks again.