I’m trying to get the odrive controller working with a 24V 20Ah lithium ion battery. I have the 24V odrive version, latest firmware (0.5.1) flashed. I’m getting a AXIS_ERROR_DC_BUS_OVER_VOLTAGE error, odrv0.vbus_voltage returns 26.214696884155273 and I measure the battery voltage at ~26V.
So my question is, is it safe to use the odrive with this slightly higher voltage? If not, what’s the maximum voltage I can use? Has anyone else had success running the odrive board from a 24V lithium ion battery?
24V is not a muiltiple of 3.7V, what sort of Lithium battery is it, 7s LiFePO4, perhaps?
Really I would suggest using the 56V version in almost all use cases, tbh… It’s more than twice as powerful, robust to over-regen, more versatile for future projects, etc. Why is there a 24V version at all
As to your question is it safe: The worst that will happen is you will destroy the DC Bus capacitors which are rated to 25V. If you are confident with a hot-air soldering station, you could replace them for 63V caps, of the highest value that will fit in the footprint.
Depending on the actual V3.6 BoM, you could come close to the limit of the FETs, but I think these are either 30V or even 60V parts, even on the 24V board. If you have a good magnifying glass, maybe you can read the part number and look them up.
AFAIK, all the other parts on the 24V board are good for 56V
You would then need to modify the firmware to allow operation up to 28V (you need some headroom over 26.2V because the ODrive will want to send current back to the battery when decelerating)
Thank you so much @towen!
ok, so what you’re saying is I should have bought the 56V versions!! I’ll see if odrive will allow me to return it, if not, I don’t mind going in there and modifying the caps.
(battery was sourced as i needed a high AH that would physically fit - so picked this one based on dimensions it’s of the “generic rectangle” type lol
Generic rectangle type…
I’d be interested to know what’s inside that… But it’s typical of those Chinese “generic rectangle” products that they provide no datasheet whatsoever…
For example, is it possible to use regen with this battery? Or is there a switching power supply inside that regulates the output voltage to 24V, but also acts as a diode and prevents charge flowing in through the output terminals?
But yes, I think the 24V / 56V ODrive are somewhat misleadingly named. They refer to the absolute maximum supply voltage, not any “recommended” supply voltage.
Both versions will happily function down to 8 volts input, and their output current ratings are the same.
The only time I might pick the 24V version is if I was making a large number of robots based on 12V batteries and cost was an issue… no forget it, I would still use the 56V version
I’ve gone ahead and ordered some 56V ones, seemed easier than mucking about with replacing blown caps
Alas my application is space constrained - I have a shallow space (80mm) in which to fit one in - and this “generic rectangle” one did the job. I think a slip of paper came with it, I’ll check when I get back to the office and post here for posterity
