Hi @robspace,
So according to the DeSET mapping boat blog post I think the maximum voltage from the e-bike batteries I used was 28V which is lower than the torqeedo’s battery which whose max voltage is about 32V according to my testing.
I bench tested the Torqeedo motor up to 40V and it seemed OK but all I did was test that the motor turned OK. I didn’t test it under load nor for a long period of time so higher voltages may cause damage in practice. One issue I noticed was that the battery voltage monitor built into the Torqeedo would not report voltages above 33V or so. So even if the external battery was providing 40V it would still only report 33V
Here’s what I wrote in the blog post.
The Panasonic batteries have a lower voltage (28V) than the Torqeedo batteries (32V) meaning the vehicle’s top speed is slightly lower than it could be. This issue is especially pronounced after the batteries start getting low. Finding an alternative battery of 32V seems nearly impossible but the Torqeedo motor appears to be able to accept up to 40V (only bench tested) so some other 36V batteries may be a good option (Makita power tool batteries maybe? ).