On 11/9/2021 12:39 AM, John Hosken (USA) wrote: [sniped]
I assume 100ah will mow a pretty big lawn. None of the lithium battery posts I have seen mentioned the ah rating of the batteries they used. Battman says his E-20 uses about 1ah/minute. Has anyone tried this? John
I used surplus / used lithium battery modules made for BMW i3 cars. They are made up of 5 pairs of 35AH cells in series, so I have 2 of these in series to get 36-41V. One set of the above is 70AH. I have 2 sets paralleled, so I have 140AH. Theoretically, 1 set should give more or less the same run time as a regular quality set of LA because we are drawing at more than a 20HR rate, so we never get the AH capacity that LA are rated at. One set of these lithium batteries are rated to deliver 150A continuously, so they have no problem dealing with an ET. Since deeper cycles "wear out" batteries faster than shallow cycles, I went with 2 sets for 140AH. The cycle life should be a lot higher than LA. The batteries cost about $250 each module, and another $500 +/- for the BMS and other bits. The ones I bought were tested to still have 90% of their original rated capacity.
My E14 draws about 50A mowing, varies by incline, speed, and grass density of course.
Dave