# low battery current



## mik420 (May 10, 2011)

i am having a issue with my car it is a 1960 Austin healey converted to 72 volt using 12 trogen 105 and a alltrex 72300 controller with a d&d es-15 motor. my problem is low current only about 25 to 100 amps but no voltage drop all connections are tight.when i monitor the controller it says current to the motor is OK but the battery current is low. am confused.


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## alvin (Jul 26, 2008)

mik420 

welcome. My battery amps are usually about half the motor amps till the battery voltage sags real low.

I would like to see a pic of your car.

Alvin


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## mik420 (May 10, 2011)

here you go ,sometimes i can use 300 amps and sometimes only 50 seems inconstant, and the voltage doesn't drop when at 300 amps 72 at 50 amps still 72


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## PStechPaul (May 1, 2012)

You should feel a huge decrease in power if those readings are true. I think there is something wrong with your metering. What are you using to read current and voltage?


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## Ziggythewiz (May 16, 2010)

Sounds like an overheat scenario. How warm is your controller when it only gives 50A?


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## mik420 (May 10, 2011)

yes a huge decrease that's what concerns me for the volts and amps i am using the software that comes with the controller and my dash gauges the temp i monitored (with the software) was 55.7c runs -25 to 85c and shutdown at 95c,fully load tested batteries,on a fresh charge, it is just beyond me,haven't submitted the data to alltrex yet will do that next week to see what they say it could be


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## mik420 (May 10, 2011)

here is the data,look at it and tell what you think


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## alvin (Jul 26, 2008)

I like your Bug Eye Sprite. 

55.7c does not sound to hot to me. 300 amps cut back to 50 could be current limiting in the controller.

Will it hold a constant current at a lower level ?

I could not make any sense of the data doc.

Alvin


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## Ziggythewiz (May 16, 2010)

Is the voltage 72 at 0 amps as well? If yes the batteries aren't charged as they should be around 76-80 when full. If no, the controller may be limiting the voltage drop to 72, so it limits the current to keep it from dropping lower than that.


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## PStechPaul (May 1, 2012)

You need to save the file as CSV and then open it as a spreadsheet:


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## mik420 (May 10, 2011)

thank you for doing that i could not figure out how to post it as a spreadsheet but you see what my problem is low motor voltage and battery current am using alltrex oem mapping for throttle


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## GizmoEV (Nov 28, 2009)

Remember that Battery Volts * Battery Amps = Motor Volts * Motor Amps - losses. Battery amps do not equal motor amps until the controller is full on which is not the same as full throttle. Essentially, on a full throttle take off, motor amps will be at max while the battery amps will climb until both are the same then both motor and battery amps will drop together as the motor continues to speed up.

What are the controller settings at. Like someone said, is it set to not let the battery voltage drop below 72V? If so then you need to lower that value.


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## mik420 (May 10, 2011)

i don't see that on my controller but i will ask on tue. when i talk to alltrex. thank you for your input


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## iop95 (Sep 4, 2012)

What kind of excitation have this motor? Seem to be parallel or compund excitation and it's a problem in excitation (don't exist or it's very low). Check excitation coils/connections.


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## mik420 (May 10, 2011)

i want to thank everyone who replied to this thread it turned out to be a throttle mapping issue and it has been resolved ,again thanks all


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## GizmoEV (Nov 28, 2009)

Sweet!!!!


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