single cell tester

[davec]

Here's a simple single cell tester i use occasionally-

parts:
2x4 = free
light bulb ( made by variety of vendors, ancor makes 12v, there's 40w 12v torpedo lights mine were 2 dollar a piece made by Symban)
2x 50w 12v
any DC meter (i use watt's up) but any multi meter/amp meter will do
14 AWG wire
6x terminal rings
2x anderson power pole connectors
2x leviton Keyless Lamp holder, White - 1.50 a piece

View attachment 1

Max load of 100W for both light bulbs, or 50w with one bulb.
For big packs i have an option of placing 120v 100-200W bulbs in each socket for a bigger load draw.
my next project will include some 0.2 50w resistors instead of bulbs... but this project works well

 

[SamTexas]

The highest voltage of a single cell is 4.20V. The lightbulbs are 12V rated. You'll will never get the max 100W (or 50W) power. The most you can get is about 1/3 of the max.

The get the max power you'd have to discharge 3 or 4 cells in series.

 

[dogman dan]

That makes logical sense. What do you actually see on the wattmeter? With one bulb, with two bulbs.

 

[davec]

dogman:
I will confirm next week- my watt's up meter decided to retire
a new one is in the mail

 

[davec]

ok - with 2 bulbs 4.24amp draw
with 1 bulb - about 2.14 amp
this is for 1 lifepo4 cell
very light load- might need more bulbs-- but i think ill just go with resistors instead....

with 2 light bulbs

with 1 bulb in the socket