Cells connected serially - Amperage, if I put few broken cells ??

[bcroe]

Once you know Voc and Isc, you can determine consistency of your cells with a dummy load.
Estimate the load (ohms and watts) for 80% of the Voc. Connect that in good sun and see if
you actually get 80% of Voc, which should be near Vmp. If voltage is way down, some bad
cells are holding the rest back. I would reduce the load current (increase resistance) until I
got 80% of Voc and note the current, that might be a current compatible with all the cells.
good luck, Bruce Roe

[sensij]

Well 12V 7Ah, from UPS battery. Well is there anything for which i can use this panel, or it's peace of garbage. Maybe for phone charging, Flash lights etc. ?

How i can measure current, can I use car light bulb, and put it in circle over multimtere ?

Start by measuring the Voc... the voltage across the + and - side when it isn't connected to anything. If that looks healthy, you can just connect the + and - to your multimeter leads in amperage mode, as long as your meter has a setting that will tolerate a couple amps. Shorting a cell this way won't hurt it; it gives you the ability to measure Isc if you measure the current at mid-day with the cell oriented to be directly facing the sun.

If both Voc and Isc look ok, putting in an incandescent bulb or other small resistive load is ok too, to get some idea of how it handles a load. Chances are good that cell is trash though.

[liska]

You are right, the lowest current output cell in a string will dictate the maximum current overall. Trying to
get more current will probably badly heat the bad cell (like this cell did to me) and cause a big voltage drop.

The same applies to the second question; parallel cells will be limited by singles.

You are a long way from charging a battery fast, what exact battery is it? May a maintainer. Bruce Roe

Well 12V 7Ah, from UPS battery. Well is there anything for which i can use this panel, or it's peace of garbage. Maybe for phone charging, Flash lights etc. ?

How i can measure current, can I use car light bulb, and put it in circle over multimtere ?

[bcroe]

Hello guys, one newbie arrived here
Just bought cells from ebay, almost finished connectig them in series, but I broke few. So my question is can I connect my broken cells with other, how it will affect current ? For voltage i know it will just be added up, right ?

Somwhere i read that current will be dicated by lowest outputing cell, so that broken cell can reduce my current ?

And my second question is ?
Can i connect few solar cells in parallel, to gain Amperage and then continue buy connecting them in series?

My goal is to try and charge 12V battery, so what is best for me, if my goal is to charge that battery fast.
Specification:

Average Power (Watts): 0.63Wp
Average Current (Amps): 1.26 Imax
Average Voltage (Volts): 0.5 Vmax

You are right, the lowest current output cell in a string will dictate the maximum current overall. Trying to
get more current will probably badly heat the bad cell (like this cell did to me) and cause a big voltage drop.

The same applies to the second question; parallel cells will be limited by singles.

You are a long way from charging a battery fast, what exact battery is it? May a maintainer. Bruce Roe

[liska]

Hello guys, one newbie arrived here
Just bought cells from ebay (these cells), almost finished connectig them in series, but I broke few. So my question is can I connect my broken cells with other, how it will affect current ? For voltage i know it will just be added up, right ?

Somwhere i read that current will be dicated by lowest outputing cell, so that broken cell can reduce my current ?

And my second question is ?
Can i connect few solar cells in parallel, to gain Amperage and then continue buy connecting them in series?



My goal is to try and charge 12V battery, so what is best for me, if my goal is to charge that battery fast.

Specification:

Average Power (Watts): 0.63Wp
Average Current (Amps): 1.26 Imax
Average Voltage (Volts): 0.5 Vmax