Join Date: Oct 2014
Location: Deale, MD
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Re: Electric Conversion log for Kahleesea
I'm going with Chevy Volt batteries. They have a number of advantages that makes them well suited to what I'm doing. The form factor works well for me, they use pouch cells, they have built in temperature sensors, and they're over-engineered for what I'm trying to do. The max power I can draw through the motor controller is about 0.8C, and I'll be well below that for cruising speed.
They'll be living in an ABYC compliant battery box, wired in parallel, an using a dilithium BMS. I'll be exporting the BMS data to a wifi-enabled Photon so I can monitor it remotely. I'm using a relatively low-powered charger, at least at first, and will be monitoring the charge cycles like a hawk until I'm confident they can charge unattended. There are multiple points at which the charging circuit can fail-open: The BMS, the Charger and the Photon will all have the ability to cut the power should anything go amiss.
On the controller side, it monitors engine temp, controller temp, voltage, etc.
I'll be taking things slowly at first. I'll probably start by running the motor in the slip for a full discharge and do a full charge cycle while I'm on the boat so I can keep an eye on things like cell temp. The BMS has automatic individual cell control, so I can get a history of each cell as it charges.
I'm a long way from testing, though. I have to finish the physical install, which looks like it's going to take some aft bulkhead redesign. The space for the battery box exists, but the openings aren't large enough to maneuver the box into it. I'll probably have to go in from below by removing everything not fiberglassed in place and then rebuilding it all afterwards. We shall see.