EZGO RXV: Starter Amazon Battery and Shunt

[AlexBen]

Oh boy. Found too late I can not yet post a link. Amazon sells this, advertised as shown. I'll come back and post a link when I can.

ECO-WORTHY 48V 50Ah Metal Case LiFePO4 Battery, Built-in BMS, Replacement of Lead-Acid Battery, Allows Discharging at -4℉ and Charging at 32℉, Stackable, for Solar Off-Grid, Golf Cart, Lawn Mower, RV

I've acquired a used EZGO 2103 RXV with dead lead acids, and corroded wires. Otherwise decent shape. I'm going to convert it to Lithium. I do not need extended crazy range as this will be a cart used at the motorsport events for fun, shuttle to get gas, go to different turns to watch the race, possibly go to grab food or washroom breaks.

The above battery says it is capable of 200 amps output peak, so I think that should be adequate. I was planning on a Victron BMV 712 display and shunt to keep accurate SOC information on the dashboard, and it has BT to the phone as well. My research has shown that many BMS aren't reliable for SOC vs a true shunt, so this item would fit the bill. Open to suggestions for a charger. I do plan on wiring in a switch and keeping a 18V DeWalt battery wired up in the box in the unlikely event that the main battery dies, and I need to unlock the parking.

I don't mean any disrespect to vendors that advertise here, I'm aware that there are all in one kits, one that is built to automatically keep the parking brake system active in the event of low charge or failure of the main bank. But I simply don't want to spend that much. I'm more than able to convert the current receptical and re-wire the old plug for a new charger.

(Long term plan is definitely adding an MMPT charger and PV on the roof as I can keep the cart outdoors on race weekends, and let it top off on its own.)

Truck will have 1200watts solar and a 24x305 battery to recharge the cart if needed. Appreciate constructive criticism. New to the cart world, but have been reading a ton on converting my Truck/RV/Car hauler to Lithium and Solar, and have bought most of what I need for that conversion.

[suzook]

50ah seems a bit low. Spend the $ and get a 100ah batt.

[AlexBen]

Originally Posted by suzook

50ah seems a bit low. Spend the $ and get a 100ah batt.

Thanks for your input.

I need to get this moving first.

If I find that I need more range, I’ll parallel another with it. I know well that a single battery is preferable to a pair of parallel ones for longevity. I’ll be lucky if the cart comes out to play 8 weekends each summer. It’s an extravagance. At that rate of use, this battery (or pair) will be fine either way.

Any suggestions for affordable charger?

[ojo]

The range isn't the problem with the 50ah, probably enough for your usage but, with typical continuous output of 50 amps it's too weak for a cart like the RXV. On fast accelerating you'll see a current draw of 200+ amps easily and that will trip the BMS, lock the brake and you'll thrown out of the seat ( or out of the cart ).

[AlexBen]

Originally Posted by ojo

The range isn't the problem with the 50ah, probably enough for your usage but, with typical continuous output of 50 amps it's too weak for a cart like the RXV. On fast accelerating you'll see a current draw of 200+ amps easily and that will trip the BMS, lock the brake and you'll thrown out of the seat ( or out of the cart ).

Thank you.
I've seen your other posts mentioning this. The BMS clearly is capable of 200 amps for that surge. There are some batteries that don't mention a specification for that and in that case, yes, buyer beware, won't handle much more than 50 amp rating I'd suspect, but this one does.

You sure that the RXV will constantly draw more than 200 amps on start up? Are people measuring that with stock controllers, stock wheels, and having knocked off 250 lb of lead acid in exchange for a light battery? Is this effect when people do sort of like "drag racing and stomp on the throttle" from a dead stop, or even reasonable conservative use?

[TheCartBoy]

It's not a great option for an RXV, but you can adjust your driving style to make it work. No fast acceleration, no full throttle up hills, no oversized passengers!

Retune the controller so you always have some residual in the tank for tow mode.

[ojo]

Originally Posted by AlexBen

Thank you.
I've seen your other posts mentioning this. The BMS clearly is capable of 200 amps for that surge. There are some batteries that don't mention a specification for that and in that case, yes, buyer beware, won't handle much more than 50 amp rating I'd suspect, but this one does.

You sure that the RXV will constantly draw more than 200 amps on start up? Are people measuring that with stock controllers, stock wheels, and having knocked off 250 lb of lead acid in exchange for a light battery? Is this effect when people do sort of like "drag racing and stomp on the throttle" from a dead stop, or even reasonable conservative use?

I can't find any specs for the Eco-Worthy battery, typical discharge rate would be 50a cont./100a max for a few seconds. Amp draw of the RXV varies anywhere from ~ 40a to 200a + when accelerating ( not aggressive). At least two of those Eco's in parallel could work in my opinion.

** I'd second what TheCartBoy says!

[AlexBen]

There is another version 50 ah with peak amps 300.

Again, unable to post link yet. Same company but but not the flat version one might stack, but standard configuration.

[AlexBen]

This is the spec of a battery I would use. 300 amps max

Granted limited range, but 300 Amps would cover the surge issue.

Must be a different BMS than their flat metal one.

[Pat911]

Buyer beware.