MK Battery Problems

[Cascade]

Thanks, Al

You are right; I did not take into account the impedance of the charger. We were simply looking for a way to understand what the battery and charger were doing and be able to explain to the kids how to use the chargers. Yes, the time base is reversed because we wanted to know based on the charging voltage how long it might be until a battery would be charged enough to use in a match if we got into a situation like the championship rounds, where batteries may be needed quickly.

Here is how we tested each battery:

1. We put together 5, 200 mA, 12 vdc bulbs in parallel to equal a 1 amp load.
2. Attached the load to a battery until the load voltage dropped to 10 vdc.
3. Attached the battery charger to a battery with 1 DMM in series to measure the charging current and 1 DMM across the battery to measure the charging voltage.
4. We recorded the voltage and current readings every 10 minutes.
5. Enter the data into Excel. Each test took about 4 hours, so be patient.

Why I thought this was a valid test is the repeatability of the data. Look at the last graph where all 6 batteries just about end up right on top of one another. This validated for me, anyway, we had a new tool to use, share, and learn something from. Best part is it seems to work close enough as we have used this at three regional’s now and the kids are using it and are successful with it!

Thanks for the feedback. Yes, feel free to use the data for any purpose. We like to help where we can.

Please remember the data is based on the former Exide batteries, not the new MK brand.