Update

 The mower has been fairly consistent but I did try and push the batteries too far with bad results. One cell had swelling and was hot.

I continued to use it, but noticed a loss running time of about 6 amp hours. I finished mowing today and checked all voltages, the previously damaged cell was low and I replaced it. I had low readings on some others so I balanced them to the pack average.

I will check battery again after fully charging.

Mowing is ending but mulching leaves worked well last season so gearing up for that.