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Warp Factor III is now Alive!

63K views 230 replies 35 participants last post by  GeoMetric 
#1 ·
Pictures, data, time slips coming soon! :D
 
#14 · (Edited)
I am very satisfied with my elektromotus EMUS BMS. Customer support has been very good, Gintautas has answered all calls and emails when I needed assistance. The company sold me a high quality digital BMS with upgraded features to compensate for my packs high amperage and voltage. I am using the new version v1.8.4 Control Panel http://www.elektromotus.lt/files/EmusBMS_v1.8.4.exeand v1.8.5 firmware to update Control Unit. Works like a charm! :D
 
#19 ·
Don't trust the last digit of a digital multimeter, even if it is a Fluke ;).

With this setup, your measurement includes the contact resistances between the busbars and the probes.
Draw a constant current of for example 10A through it and measure the voltagedrop. This will give you a much more accurate result!

Kind regards
Tom
 
#21 · (Edited)
If the resistance is 0.1 you are in trouble. The average resistance would be half that meaning 0.05 so the losses in a single connector block will be 3000^2 * 0.05 = 450000 watts of waste heat in every connector block. (Note: It is impossible to have this much resistance and still get to 3000 amps. If the resistance was actually 0.1 ohms per cell then you would be limited to a short circuit current of only 37 amps average) The resistance better be closer to 0.0001 which would give 900 watts of waste heat per side or 1800 watts per cell. Still too much as this is more than a space heater on every cell.

You need to run current from one side of your connector block to the other and measure the voltage drop from a point different than the connection. Divide the voltage drop by the current to get the resistance. Example. You pass 50 amps through the block and read a voltage of 0.005 then the resistance will be 0.0001 ohms. You may have to pass quite a lot of current if your meter doesnt have a millivolt range. The effective resistance will be about half of this because of the way the cells are paralleled.
 
#23 ·




Finishing touches before hitting the track on the July 21st.
* EMUS BMS installed working properly.
* All tin complete and sealed.
* Water pump connected.
* Line-Lock connected.
* OD unit installed and wired.
* Seating brushes everyday.
* Installing rear window tomorrow.
* Gauges coming soon!
* Paint coming soon!

I see no problem racing on July 21st. :eek::eek::eek:
 
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