Not everyone is an ebike electrician either, and one might be needed here.
Dan may just need a new battery. From what I've read, Yuba doesn't sell parts or batteries for their older models, so owners have to scrounge around. It's a common battery from 3-4 years ago, and I see posts here from users trying to find something like it. They all look similar, but the plugs in the bottom might be a bit different, so unless one finds an "official" source, it could be a gamble. Dan will have to check with Yuba to see where they send their customers. If it costs $800, well that's a fair price for an exact replacement, in my opinion.
Per this manual, this cargo bike runs a 200W front Ezee motor and a 36V 10AH battery. The latter is rated 360 watt-hours. Now being a tinker and conscious of my burgeoning ebike budget, my plan would be to replace with a
higher AH downtube battery for under $500 from a US vendor. By the way, any AH rating equal to or higher than the old one will suffice, but higher AH gives more range.
I would expect the wiring to consist of just cutting the existing two power wires and re-splicing to the new battery cradle. Old charger will work, but might need a new charge plug, but a charger is about $50. If the bike has mounts for water bottles on the downtube, the battery cradles attach there, but it should be augmented with hose clamps. Clamps will work if there are no mounts.
Then again, I find bike mechanics kind of fun. If I had this Yuba, I'd probably take off the display and controller and upgrade it to 48 volts. That would be about $100 in parts.
