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how to make 12v battery from 18650 li ion batteries? Answered


I have this led strip 
Working Voltage is 12VDC.
Working Current/meter: 0.8-1A
the strip is 5 meter.

18650 x4 = 14.4 v
18650 x3 =10.8 v

How can I make it work with 18650 li ion batteries?
And how many battery must I use and how can I do that?
I think that I need driver or booster to get a stabil 12v!
work-time I need 5 h


Get a proper 12V deep cycle battery, everything else is a total waste IMHO.
Otherwise check Google and Wikipedia on how to combine batteries.
But for your lithium cells you will need either a step up, or a step down converter, best with additional battery undervoltage protection.

if we did it , can we get more capacity by group of cells and only 12 volts?

each 18650 = 3.6v
18650 x4 = 14.4 v
18650 x3 =10.8 v
I use samsung 3000map each, so if I use 4 cells I will have 4x3000 = 12000map, it will be expensive if i buy it and I love to make these things at home :).
Can I use more cells to get more capacity but only 12v?

which battery undervoltage protection can I use?

which step down can I use?

3.6 volts to 4.2 volts fully charged isn't going to give you 12 volts without some kind of regulator. Plenty of 12 volt regulators around.

Your laptop batteries may already have a protection cct attached to them, many 18650 cells do.

However Ebay or an electronics supplier can give you a suitable under and over voltage protection cct.

Cells in series will add the voltage, cells in parallel will increase capacity. So you need a series / parallel set up.

You will need to arrange for a suitable charger for such a set up though Li ion cells are sensitive to over charging - i.e. they may burst into flames.