ME1616 motor with sevcon gen4 size 6 80V low power??

[bastens_com]

I know this is an old thread but I wanted to chime in here and provide an answer to this low power issue. I have made two ATVs and a SXS with this motor now and I learned one important detail that was missed in this build and many others out there. In this example the motor was ran with a 86V nominal pack which is way too low. This motor needs 100V at the minimum to perform well, meanwhile has ok performance with 90-100V. I use Sevcon Gen4 Size6 80V controllers in my builds because it can handle the higher voltage. Note that the Sevcon 72V/80V controller can handle 116V (118v can be tolerated at the very max). So I run 28cell NMC cells which is about 103v nominal (92v - 117.6v). Really the Sevcon controller is a 72V/80V/96V/103V capable.

Let me explain in more detail. I first ran a pack with 25 cells in series in my quad. I found that when the battery was below 90v it barely had the power to push the quad on a flat hill, it didn't make sense. You might say that is because there wasn't enough current but there was plenty. My pack had the capability of 500+ Amps without much voltage sag. After much experimenting I realized the ME1507 / ME1905 / ME1616 motor by design requires 90V minimum but prefers 100+V. Motenergy does not provide enough information to tell the users this and thus why I am posting here.

Put it this way for comparison. If you look at a Hyper9 motor notice the manufacture provides dyno specs at different voltages. In their published results they say ...
(again this is a Hyper9 example for comparison, not a Motenergy motor)
Voltage -> peak kW power
132V -> 112kW
120V -> 102kW
108V -> 92kW,
96V -> 81kW
84V -> 71kW
72V -> 60kW

Notice how important voltage is to power output. Meanwhile Amps is the ability to get to the peak power but regardless without the voltage power cannot be produced.

Solution: Increase the pack voltage to 90V-116V range (103V nominal) and make sure enough Amps is there to prevent voltage sag.

 

[Easty_au]

Awesome mate, do you have a thread on your Atv and Sxs? I’m thinking of doing one too. Although i’m learning and not an electrician by any means.

 

[bastens_com]

I have many videos on building, performance, overview, etc here https://www.youtube.com/bastens

Cheers,
Patrick

 

[thriftybuilder]

Checking the sincos alignment. Seems to be spot on. In any case we tried a couple of degrees difference in either way, but have similar performance as before. When going 10 degrees of in either way we loose quite some power. So this seems to be ok. (what we don’t understand is why there are 2 values which can be changed…… We only changed the top one at 31 degrees and the bottom one of 2 degrees we didn’t. Could that be a sincos sensor calibration value to compensate for angle offset between sin and cos? And how is that determined?)

The DVT manual says that you should leave the first number set to 0, and only change the second number.