Retired Arizona Park Ranger cart joining the flock. I’m total newb to these, but an very mechanically inclined.
My cart is loaded with 6 Deka AGM batteries (it got the factory upgrade kit?) producing a whopping 1 volt, sad to say. I have not yet had this cart under power- need to ask: what is minimum voltage to just get the system to display odometer, etc? Bench supply gives 40 volts.
Looks to be a T4 running a 5HP GE, based on my reading. Has disc brakes in front.
My goal is just around the neighborhood, so not long range- 20 miles? Moderate hills. Hope to enbiggen the wheels to 16" from the 12’s once running good. 35mph would be ideal.
Thank you for any insight, suggestions. I’d like to do as much of the lithium pack building myself as I can: trying to teach mechanic-student daughter to not be intimidated by electric vehicles while knowing little myself…
First, I would measure V on each battery. You should have better than 11.2 on every battery. If not, take a car charger and boost up each one. Then locate the ends of the chain and hopefully you have better than 68V otherwise the onboard charger will not recognize the pack.
If all you get is 1v I would not hold out much hope of this pack getting you 20 miles.
Look for a round sticker on the top of each one of the batteries that has a letter and a number. It might give a clue to how old they are.
Find the status panel on the side of the charger. When plugged in it will have at least one yellow light at the AC Input light. If charging a light will be dancing around the charge rate lights. If it has a problem it will blink a code on the red light.
Report back on progress and we can go to Phase 2.
Also- look on the label above the driver’s head and find the build date of this car. I’m guessing it may be 2006 or better?
The upgraded factory battery setup back then was nine 8v batteries. Six 12v is the norm. IIRC the minimum for what you are after is around 65v.
Disc brake was stock on the fronts then. There were a few GE 5hp used over the years. Can you take a picture of the entire motor? The part number is not legible in the photo.
With lithium, that range and hills are easy. Can’t tell for certain because the p/n is worn off and really should count revolutions to be completely sure, but it looks like you have a 0613-00634 gearbox which is 12.44:1 so hills won’t be a problem. right around 22.5" diameter is the max tire size you can put on there, so 15" or 16" rims are dooable.
35mph would be easy w the 22.5"-ish tire height, lithium and a magic magnet (you can get that from @inwo)
Building your own battery pack isn’t hard. There are plently of threads on it here, especially of late with the new Samsung SDI 94 Ah cells.
I think you can run up to a 21s pack without reprogramming though. Just need to set the profile to one that will take the pack to the proper finish voltage and the BMS will open when the cells are at the proper voltage.
I just built a 21s tote battery yesterday for a client, It was a fun project, and I think it would be a perfect battery for you.
I can link to the tote, and there is a minute possibility the George is going through your area to drop off discounted cells. In the next few days or week.
Don’t worry if car doesn’t run. This battery can be easily resold. They are in high demand all over.
Ideally, you want to go over 72V for performance. You should be able to get to around 86v on the pack without having to buy a new charger, The DC shunt motors love it, that extra 12-14v will make the difference between a boring sluggish overgrown golf cart and something fun that actually can accelerate and hit 35. You’ll have to add a few magic tricks into the wiring but they are easy, both basically plug in.
The prices on those cells aren’t bad at all, but the lfp (lifepo4) have some caveats. Energy / size weight is one. They are lighter than lead, but still big and heavy in the grand scheme. You would also need to run 24 of them to hit 86-88v whereas 21 of the Samsung SDI cells that Inwo showed in the box will get you that same voltage and much lighter weight. I think the power output / drain curve on the SDIs is much better IIRC. Also, LFP’s have to be banded together and compressed or they swell and hurt themselves. All in all, it’ll be about a wash on price, and the Samsung SDIs are being made in Korea whereas those LFPs are out of China so you kind of take your chances.
BTW - do you want a bench seat and seat back for that cart? I’m scrapping out a 2002 longback (same thing as your eL). They are a bit worn, but they are in way better condition than yours. I was going to toss them in the dumpster, so you can have them for free, just cover shipping costs (we have a guy).
Found a battery pack- a local solar panel installer had a bunch of unused Samsung 22s 94ah storage modules he was selling, so I snagged his last one. These modules slide into a rack of 20 for a substantial storage solution. They have a proprietary BMS system that communicates with the rack main control system.
yeah, @Inwo and @LithiumGods have put a metric shitton of new 22s SDI packs in the hands of GEM owners, but with real BMSes that you can talk to and control. I wouldn’t count on the OEM bms. The wiring though, is gorgeous.
Just need adapters for the plugs, and I just happen to know a guy…
