Hey! It’s been a long winter here is Stockholm but it´s finally over. I haven’t been working that much in the Fiat, a new floor pan for lowering drag and a new battery gauge has been installed.
I wanted to get a better view of the energy flowing through the system so I changed my paktrakr for a E-Xpert HV. What I loose is the individual monitoring of each 12v block, what I gain is the possibility to track amp-hours (ah) going in and out of the battery.
I have a 90ah, 76,8v pack. So my total energy is about 6912 Watt. I ran a test today to see how far I would get using 80% of battery capacity (72ah). The test run included both highway, about 80Km/h, and city driving. Traffic in central Stockholm was horrible with a lot of stop & go.I used my Android to record the trip:
The Xpert uses a shunt to monitor the Ah that flows through the circuit. Removing energy from the pack is symbolized by the minus sign on the display below. When the pack is fully charged the meter show 0.0 Ah and as I start to drive the negative value increases. Basically what I did was to drive one way until I reached 50% SOC and then turned around.
Google My Tracks gives me the following info:
The meter on the fiat show 53 km:
So I’ve used about 5530W (80% of my total 6912) to drive 52 km. And I still have 20% more in the battery before it is all empty. That 106 watt per kilometer, mixed driving. Now that’s impressive.