RC Hobby eLogger for eBike battery monitoring?

[Alan2000]

I've read several posts that the wattage display on the Bafang controllers is not very accurate. I have the Bafang C963 display and was curious if it was accurate. I have an Eagle Tree eLogger I was not using from my RC airplane and I think I'll mount it to my bike to track battery data. I did a short run and the wattage numbers from the eLogger matched that of my C963. What I like about the eLogger is that it can be configured to display the data you like, and if you set it to take 1 reading per second, it will record about 6 hours of data you can download to your PC to chart, replay, review, etc. On mine I set it up to display wattage, amps, voltage, and cumulative mAh. Anyone else use one of these? I was disappointed that the C963 display does not display a numerical voltage # or cumulative mAh to know how much juice the battery has put out. With this tiny display it gives me data to manage my battery care.

** EDIT ** This doesn't seem practical due to cost, but since I already had 2 of the V3 loggers in my RC hobby box, it was a cheap alternative for me given no cost involved to add it to my bike. The new v4 eLoggers are $70 at Amazon and the LCD Display about $30. So about $100 total. The new V4 handles 100 amps and voltage from 5V to 80V. Current is measured with a true Hall Effects sensor, and not a resistance shunt, which produces heat and sucks power from your system.

 

[Hillhater]

I have been looking at alternatives to the Celllog, but missed this one somehow !
Specs ?..max volts, amps etc ?
Cost ?
Suppliers ?

Thanks
EDIT:
Now i really feel dumb !.. HK stock them .
80v , 100A, Au$80.

 

[Miles]

http://www.eagletreesystems.com/index.php?route=product/product&product_id=54

I have a V3 eLogger, Power Panel and Brushless RPM sensor. I've used it when testing motors.

 

[Alan2000]

Temporarily mounted it with some duct tape to give it a try today. Don't have the RPM sensor mounted yet so it can't display speed. I was able to manage battery usage much better so I didn't run out of juice. The mAh gauge is the perfect gas gauge for me. The battery meter on the Bafang display was rather useless on my prior trip. It showed mostly full then all of a sudden my low voltage alarm started to beep and I had to finish ride with no battery. With the mAh display it was easy to know exactly how much power I used from the pack and what I had left. Next step now is to find a way to mount it that doesn't look ghetto. Image shows end of trip data on PC. Had a leisurely ride for 1:23 with wife to park. Did a few short sprints and got up to 31.1 MPH in Power mode and pedaling. Ride distance was 9.3 miles. Power assist on bike is a lot of fun!

Logger data shows 2705ma used, 23.98 peak amps, 931 peak watts, and 36.1 lowest voltage. Charger put back in 2753ma. Not sure why display on logger shows sightly lower number for Mah used.



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[amberwolf]

Just a note about the display--since it is basically a bare LCD glass, it's really fragile, so to use it on a bike you'd probably really want to put it inside a project box so it can't get flexed or bonked, cuz it could just shatter (even a big chip at the wrong spot could render it useless).

I haven't use it in a long while now, (mostly because I'm afraid I'll break it) but the one Methods sent me a few years ago, even just handling it to hook it up to the logger I've almost dropped and broken it several times. Some of the segments / rows don't quite work like they should anymore.

 

[Alan2000]

I looked for a small project box but the electronics store didn't have anything small enough. Maybe it will fit in a Tic Tac box. Yeah, too delicate to leave exposed.

 

[amberwolf]

Tictac will probably fit and they're relatively tough for what they are, but it may be squeezed in on the ends.

Take two of the clear parts of them, cut them so they ahve just a little space to each end if they were put end to end, then fill up the space on the ends with some foam to keep it from bouncing around in there.

 

[Alan2000]

Tic Tac gas gauge complete! Steps are 1) Buy tic tac of favorite flavor. Empty contained and eat them. 2) Pull off lid and trim lid so LCD fits. 3) Put tape on LCD and tape it inside the container. 5) Insert foam behind LCD to keep it secure in place without rattles. 6) Wrap case with electrical tape or wrap of choice to secure lid and water proof the unit. I first wrapped in electrical tape then changed over to Gorilla tape and put strain relief for wire.

I'm probably going to use Velcro to mount it. It's feather light so it won't take much to keep it in place. I changed the display to show mAh, watts, voltage and pack temperature. On page 2 of display is speed and amps.





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[Hillhater]

Have you graphed any of the logged data yet ?
Always curious to see how much time is spent at peak amps/min volts ?

 

[Alan2000]

Have you graphed any of the logged data yet ?
Always curious to see how much time is spent at peak amps/min volts ?

One trip so far saved data. Still trying to figure out Excel to scale axis properly so I can put all data on one chart... 2nd pic is zoom in on data near the end. Next trip I will set logger so it takes 2 samples per second instead of only 1 to see if it catches anything different.

 

[Alan2000]

This logger has some weird issues. For example, if you put on the display watts and cumulative mAh, the data displayed for watts and mAh is garbage unless you also have amps listed on the same page. I discovered this when I deleted amps from the display...

 

[Hillhater]

Interesting data.
Thanks for posting.