Repower Decisions - My head hurts

[JaxPilot]

So, I am trying to figure out how to re-power my 99 TXT, and it's making my head hurt! I have been reading and re-reading threads trying to synthesize thoughts, ideas, opinions, calculations, and data into a cohesive answer as to the best option for me.

I'm taking a look at Lithium, 6 x 8v options, and 8 x 6v options. I think I have a grasp on the fact that the best I can do is get a *rough* idea of how the data compares given the lack of variables available for lithium for some of the more advanced calculations I've come across. I'll admit I'm educated beyond my intelligence on this topic, which in reality is not saying much.

If I take a realistic look at the use of this cart, and try to solve for the 80% of the typical mission profile, I think it will make me happiest long term. While I have visions of making it a street legal 20-25 mph vehicle so I can cruise around downtown St. Augustine, FL or to the beaches (not really on them), I don't think that will happen often. What I do believe will happen is that I will use it loaded up with guys shooting sporting clays a couple of times per week. And, if I get to the point I am competing, I have heard that it is difficult to always have access to chargers at tournaments that may last a couple of days, so I would need as much run time as practicable.

Weight is a big concern for me, from the standpoint that I think my true need is for extended run time, vs higher top speed.

70% of the time I am shooting with 3 others on my cart, which means that before I put in any kind of batteries I am now at a GVW of 1550 lbs. That's the cart, rear seat, clays basket, shooting load, and 4 guys. I think EZGO specifies a total load of about 1750 lbs.

Starting weight of 1550 means that I will see roughly the following:
Lithium 120AH Pack - 120 + 1550 = 1670 lbs
6 x 8v batteries - 375 + 1550 = 1925 lbs
8 x 6v batteries - 495 + 1550 = 2045

I know it is near impossible to calculate how a cart performs under such a load, but I have to think dropping weight at this point is a good thing.

However, dropping cash is getting harder and harder to do, and a 120 AH Lithium is going to set me back $1800 - $2200, vs. $700-$800 for the FLA options.

My understanding is that the stock 2.5 HP motor = ~1860 Watts (2.5*745).

The 6 x 8V pack has 8160 watt-hours (170AH x 48v), 4080 usable at 50% SOC. The 8 x 6v pack has 10,800 watt-hours (225AH * 48v), 5,400 usable at 50% SOC. The lithium 120AH pack has 6480 watt-hours, but 5,184 usable at 80% DOD.

So IIRC on how to do the math, the 6 pack has 2.2 hours of runtime, while the 8 pack has 2.9 hours of runtime, and the Lithium comes in between them at 2.8. At 18 MPH, if that was achievable at 2045 pounds, 22" tires, and 500 amp controller, it would give me a theoretical range of 40 and 52 miles, respectively on FLA. Lithium would give me 20 miles, but maybe more since the lighter cart could be faster. Doesn't seem worth the cost, unless the speed increase were really, really, significant.

I guess I'm wondering if the extra 120 pounds (6%) of 6 volts is worth the extra 30% of mileage. Actually, I'm wondering if any of this is even valid for a cart operating that heavy!

Any thoughts or opinions on my ramblings? Which way would *you* go if you were in my position?

[yurtle]

I'd go for 8 6 volts, which is what I did.

[agpfl]

You will get way more than 20 miles from an 120Ah Lithium pack.

I have an 82Ah pack on a 2005 TXT PDS and get 30 miles with 2 normal sized adults and 2 kids. No battery maintenance is awesome.

[yurtle]

So others can comment, tell us what drive system you have.

[JoeBleaux]

What about a gas cart if you are allowed to use one at your clays range and events - it would seem odd to worry about cart noise at a shooting event, but ??? You can quiet it down with aftermarket exhaust add-ons/mufflers. If you find the need to pep it up, there are lots of ways to do it. I have a stock Club Car gas cart and now, a (stock) TXT series cart (it replaced a older resistor EZGO) and the gas cart is faster and more powerful, but obviously, it makes more noise. The range on a gas cart is only limited by gas availability and it is a lot easier to carry a full tank and a 5 gal can than a 40 mile long extension cord (think upgraded battery cables are large? Think how much cart you'd need to carry 40 miles of 9/0 ). I have a add-on "silencer" on my mostly stock ATV and it does make a big difference.

If you must stay with batteries, another suggestion would be a inverter genset, like the Honda EU2000i (or similar) if you can use it overnight at shooting events. The Hondas are pricey (1000.00 new, but deals on good used ones pop up, esp. in places like Florida where RVers and hurricane fears make them popular items) and the "knockoffs" less so, but you can run it overnight on a couple of gals of gas. If you've never heard one running, they are _quiet_. You can have a normal conversation standing over one.

[yurtle]

If a gasser a possibility, look at an EZGO WorkHorse. Disable the governor and you will have a Bada$$ buggy.

Mine had a dump bed, which was pretty decent for a three passenger bed.

[bronsonj]

By your math lithium had 2.8 hours run time, eight 6v had 2.9 hours run time and six 8v had 2.2 hours run time.

So your lithium range should be almost the same as eight 6v batteries. So your estimate of 20 miles on lithium seems way low compared to 40 on 8v and 52 on 6v. I would have expected closer to 50 miles. Again, just using your numbers shown above.

I also live in central FL and the heat shortens lead acid battery life (it seems) so lithium seems like the way to go (assuming money grows on trees).

[scottyb]

Yes lithium (minus 300# and $1000) will make you go further.

[Sergio]

I agree, lithium is the only solution for you.

Also, your comparisons for range missed how the AH ratings are based on different standards.

Lead acid batteries give their AH on a 20 hour rating, so You only get 225AH out of T-105 with a constant load of 11.25 amps (225/20).

If You look at their datasheet, with a 120 amp load you only get about 80 minutes until the battery is totally dead (5.25v each or 42v for the pack).

Lithium batteries AH ratings are 1 hour rating, so 120AH means a load of 120 amp for 1 hour.

The lithium batteries will also deliver their rated AH at a more consistent rate until the very end when the BMS will shut the load OFF.

When You add the efficiency gained by weight reduction, cable reduction, connection reduction and time saved on maintenance, it is the best solution for you.

The bonus is that you will have an on-board charger so all you need is a regular AC outlet to get a quick charge as they lithium charges a lot faster too.

[TexTurbo]

JaxPilot

I am also reworking a TXT, mines a 98 so basically the same. I have followed your posts on the re-do...props to you for such a complete workover !!

I struggled with the same concerns as you with "power up options".. you mentioned an 8x6v thought.. with our configuration, did you successfully work up a "floor plan" for the battery layout.... I may have (and probably did) missed something but I could only work in 7...

I have recently visited with a neighbor with a 2000 TXT 6x8v, Scottys 484 package 12" 22s tires.....I have ridden with him for 2 circuits of our community (24 miles)..and it still had plenty of zip..No meter to see the drop, but that's what I saw....

BTW, I grew up in Jax, many years in the Fla Ang (f102,106, f-15s
) was a surfer dude, lived in Palm Valley..what is now Sawgrass.

Enjoy your new buggy !