whats best way to test solar cell

Hi, just purchased a couple of 260w solar panels really cheap, the glass is shattered on both but the voltage is still showing 40v on an overcast day, whats best way to test the amps output ? i tried charging direct to one of my ebike batteries and the charge voltage was only showing 500ma or so

I bought a few 230W panels recently and I just used a clamp type Multimeter that can measure DC amps.
The spec sheet will help you out, in my case it said 37V open circuit and 8A short circuit.

So on a sunny day I measured about 38-39V open circuit and 9A short circuit and that's all there was to it.
I go them mounted on my roof and they perform like new even though they are like ~10 years old.

cool thanks, ive got 2 x 260w panels with the glass shattered but they both seem to work okay - im looking into building a mini powerwall setup and just wondering what kit to go with, an hybrid inverter or seperate charge controller, what size lipo banks too ? 12v 24 volt or more, anyone got any info

I recommend 48V but if you can't go that high then 24V is the lowest I'd go.
A Grid tie Inverter is about the most convenient and simple option, I have some stuff hooked up to a 2.5KW Inverter and I regret not getting at least a UPS Inverter.

dont know wether to go a small victron charge conntroller or go a hybrid house inverter so i can hook upto the house supply one day. also lithium ion 26650 batteries or lifepo4 cells,