Wednesday, August 19, 2009
Saturday, August 1, 2009
Back on the road - tuning for temperature!
I finally received my replacement battery and put the traction pack back together. Electro has been great for the past few weeks, getting me to work and back. We've had a bit of a heat wave here in the PNW, and I didn't connect the fact that the Zilla motor controller was getting hot with the hotter ambient temperature.
But as we approached the all-time record this last week of 103 F, I noticed the check engine warning light from the Zilla would come on earlier and earlier in the drive. I used to just connect that light with battery low warning, but found out that it is also when the Zilla is approaching thermal cutoff of 100 C. Closer watching with ZillaView during driving showed that I was getting upwards to 80 C, which cuts back on the current, but doesn't completely cut out. Anyway, I checked my liquid cooling system, and things are fine, but the mini-radiator/reservoir storing the coolant can't get cool enough on its own, especially when the days get hot. So I installed an extra 12 VDC computer fan, mounted to the radiator to help expedite the heat dissipation. I would prefer to expose the radiator to RAM airflow, but there isn't a convenient space for that.
Tested the new cooling arrangement the other day on my 'devil's run' test hill (1/4 mile extreme grade uphill). The temperature rose predictably, but leveled off at 70 C and recovered to a lower temp fairly quickly! The warning light still flashed at me, but I think that is going to be a fact of life on extremely hot days.
But as we approached the all-time record this last week of 103 F, I noticed the check engine warning light from the Zilla would come on earlier and earlier in the drive. I used to just connect that light with battery low warning, but found out that it is also when the Zilla is approaching thermal cutoff of 100 C. Closer watching with ZillaView during driving showed that I was getting upwards to 80 C, which cuts back on the current, but doesn't completely cut out. Anyway, I checked my liquid cooling system, and things are fine, but the mini-radiator/reservoir storing the coolant can't get cool enough on its own, especially when the days get hot. So I installed an extra 12 VDC computer fan, mounted to the radiator to help expedite the heat dissipation. I would prefer to expose the radiator to RAM airflow, but there isn't a convenient space for that.
Tested the new cooling arrangement the other day on my 'devil's run' test hill (1/4 mile extreme grade uphill). The temperature rose predictably, but leveled off at 70 C and recovered to a lower temp fairly quickly! The warning light still flashed at me, but I think that is going to be a fact of life on extremely hot days.
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