Tuesday, April 20, 2010

Ellie Climbs the Hill

The lithium batteries (48 of the TS 100Ah) appear to be working fine on my 17 mile hill climb coming home from work. I climb 2600 feet, the last half at a 6% grade. With the lead pack the trip used about 37~38 Ah's and the car now uses 32~33 Ah's with 500 lbs. less in battery weight. She rides about an inch higher now. I leave the power selector in Normal mode with my foot a bit less than half way down on the pedal. This shows from 110 to 150 amps being drawn to maintain normal speed on the very winding mountain road.

It's funny to start with it showing 162 volts and get home showing 157 volts, after allowing a minute for the pack to settle. With AGM's it went from 170v down to around 145v and didn't recover much after settling. This killed the PowerSonic AGM's in less than 70 cycles. A better brand of AGM's would have lasted longer, I just didn't think that repeatedly drawing only 38 Ah's would be that hard on them.

I'm using a Hardy BMS and the 48 cells are staying fairly even on the three trips I've made up the hill so far, lowest reading was 2.877V with the highest cell at 3.062V at the same moment. My hope is that they'll stay that way if I don't discharge them below 2.8 volts, I use less than 40 Ah's between recharges, and I'm not drawing more than 150 amps.