11-30-2020, 04:22 PM | #1 |
Not Yet Wild
Join Date: Aug 2015
Posts: 46
|
Starting my EZGO Marathon Lithium build.
Finally getting around to posting my build.
I have a 1993 (I believe) Marathon 3 Wheeler. I picked it up about 5 years ago, put a set of 6, 6V Trojans in it, and the wife and I use it around the yard. We have 5 Acres, pretty flat. Mostly I got it for running around the yard, and running to the neighbors the back way. Since it's electric and silent, it's great for going over to the neighbors, and if we leave late at night, there's no gas engine running to wake anybody up. Also, if the wife uses it, and she has an adult beverage, she's not on the road with her car, to go 700 feet. We dubbed it "Marty" as in, "Marty the Party Cart". Its no looker, but it gets the job done. As well as new batteries 5 years ago, I installed a 36V-12V power converter, and added some LED headlights. Over the past year, it's started to need water in the batteries. No big deal, but here late in the fall, the wife left the key on a couple times, which I thought killed the batteries. When it would move, you would push the pedal down, and all the sudden it would JUMP at full speed. A little research led me to believe the batteries were shot. Then it got to the point it wouldn't move at all. I decided to go Lithium, and upgrade to 48V (ish). I picked a list of parts, and got them ordered. So far: Alltrax 48500 SW200 Main Contactor SW202 Reversing Contactors Precharge Resistor and Diodes Qty 4 5S BMW 75Ah batteries Qty 2 4S BMW 75Ah batteries (All of these will parallel together to make a 150Ah 14S Battery.) I got these from BatteryHookup. 14S BMS from BatteryHookup. (It's supposed to have low temp cutoff) Parts to build the LV and HV monitoring circuit (ala Sergio) 10A 14S Charger 35A DC to DC converter New Radio Plum Quick Widowmaker Motor I had done a little troubleshooting, and found that the reason it wouldn't move on it's own was that I believe the original Curtis controller gave out. I jacked up the rear end, and used 2 of the batteries (12V), through the reversing switch, and the motor turned. I also found out that I have the Blue GE motor, which from my research is 36V only, and not as strong as the AMD motor. I have pulled all the batteries out, and I see I have some cleanup and painting to do. Yesterday I pulled the motor to confirm it's the 19 Spline. I also played with battery layouts to minimize the fabrication needed. I think by moving the pot box around, and relocating a diagonal brace to give me 1/4" more room, I think they will all fit. Once the diagonal brace in the last pic is moved, that askew battery will sit flat. I think so far the biggest challenge will be top-balancing the batteries, and hooking good sized wires to actually parallel up the cells. The busbars in these batteries are welded in, so my options for paralleling up cells will require creativity. |
|
Thread Tools | |
Display Modes | |
|
Similar Threads | ||||
Thread | Forum | |||
Lowered 97' EZGO TXT lithium 36v to 48v build | On Road Golf Carts! | |||
ezgo Marathon Starting | Gas EZGO | |||
Starting my lithium build | All things Lithium | |||
Ezgo marathon starting without pedal | Gas EZGO | |||
I will be starting my ezgo build soon | Lifted Golf Carts |