Moon rover Yamaha G16 project

[smackley]

One of a few projects, that I'm finally getting around to with Covid remote work days, is a rusty old G16 EV. I have a goal to eventually get a lithium setup, but it's a bit overwhelming as I get started.

So far, the cart has been torn down and had the frame sanded down to clear the rust. Everything got welded back into shap e in any areas with too much missing metal, and then all was coated with POR15 to prevent future rust.

I had to cut out the entire old battery tray, weld in a new tray for the future lithium stack, and fab up an aluminum tray liner. Swing arms got new bushings as well.

[smackley]

D&D motor added, and I have an Alltrax controller on the way as well.

[Swan]

nice , going to be a good ride for you

[bronsonj]

You going to put 'Cougar Life' on the golf cart too? LOL!

Lookin good so far!

[smackley]

No major updates this weekend. I was at the beach all week with the family, so no project progress but I did order a bunch of stuff that should help me keep moving along. The only remaining items are deciding which batteries and BMS to go with. Leaning towards a 16s2p leaf setup, but I really feel out of my element here. I'm a mechanical guy, but battery tech feels a bit...spooky. I guess I'll just drive in, follow some great threads, and hope for the best!

[bronsonj]

With the lithium cells they are rated at 4.2v each. But nobody charges that high. Sellers tell you to charge to 4.15vpc max. I charge to 4.06vpc which is lower than most, but the lower you charge the longer life you get. From reading the forum, it appears that most charge between 4.10vpc to 4.12vpc.

A 16S pack charged to 4.12vpc would be 65.92 volts. If the Alltrax controller is a 48V unit then the max you can program it to handle is 62v. The most common lithium pack you'll see on the forum is a 14S pack. Either 1P or 2P.

[smackley]

Originally Posted by bronsonj

With the lithium cells they are rated at 4.2v each. But nobody charges that high. Sellers tell you to charge to 4.15vpc max. I charge to 4.06vpc which is lower than most, but the lower you charge the longer life you get. From reading the forum, it appears that most charge between 4.10vpc to 4.12vpc.

A 16S pack charged to 4.12vpc would be 65.92 volts. If the Alltrax controller is a 48V unit then the max you can program it to handle is 62v. The most common lithium pack you'll see on the forum is a 14S pack. Either 1P or 2P.

Thanks for the info! I mistakenly was assuming nominal voltage for LiMn chemistry (I used to deal with a lot of 18650/350 based devices). 14s2p Leaf setup seems easy to get put together, but I'm still a bit fuzzy on how to arrange different relays to turn on the "ignition" power, and a charger cutoff circuit. I'd like a BMS that has an output signal to open a charging feeder contactor, or is it better to find a charger that takes that same output as a direct input? I'm such an amateur at this, but I hope that made sense.

[bronsonj]

You're already ahead of the curve compared to many who succeed at the lithium conversion! You've already got 18650 experience.

14s2p is by far the most common and leaf cells are the easiest to work with.
For the cutoff, no bms out there can handle the load of a golf cart so what they do is the BMS triggers an HD solenoid. Sergio did a full write up about this, I'll look for the link.

----- found some of those links -----

https://www.buggiesgonewild.com/show...ghlight=sergio

and 2/3rds the way down on this page:
https://www.buggiesgonewild.com/show...=sergio&page=6