Battery design

Hello all,

Currently I got 2 solar panels HIT Panasonic,330watt58v and 6amp each.
I need to makea 18650 batterythat could be gradually enhanced in capacity when I add more panels and more 18650 cellsin future.
Can some one help me to design the battery with capability to increase its capacity step by step.Should I do 24v battery system or 48v. Please advise.

Regards,
Sabrin

Hi

Voltage depends on your end goal I would say. You can of course do 24V (7s) now but then you would most likely need to swap out gear later on when upgrading the system.

For a house-powerwall 14s aka 48VDC system is most efficient.

Not giving us much to go on here

Being a DIY forum, you can look at other projects for inspiration but the final design should really be yours. Many members have accomplished something similar but in different ways.

You should take into consideration the below items:

• What is the size of your load?
• How much capacity / runtime do you need at a bare minimum to get this off the ground?
• Your voltage selection should be a consideration when looking at inverter choices, but I agree with what daromer said.
• Modular packs in series have their own challenges when trying to introduce packs of different voltage in/out of the system.
• Modular packs would have a different approach when considering BMS / monitoring.

Once you scale this into something larger, you might find that the modular design adds complexity you dont want, and would want to re-configure the setup to 7 to 14 larger packs with a more robust single BMS. Personally I would be sure of the direction long term. I know its exciting to want to make a battery pack sooner than later so you can start collecting solar power, but patience is a good thing. Just focus on the acquisition of cells, testing, and learning before rushing into building.