OT Electric Golf Cart Charging Question

I posted this on a Golf Cart Forum also, lookin for opinins from experienced electric golf cart dudes. My newly acquired "gift" is a 1997 EZ GO equipped with six Trojan T 105 6 volt batteries. Heres my post:

Okay Im NOT very electric golf cart experienced but am a retired electrical engineer and afraid my "Brainstorm" wont work, but wanted to run it past you experienced cart owners.

A Honda 2000 EU can work to run my charger when shes sets not a problem.....But I have this "Brainstorm" to stick the genset on the cart and try to charge it WHILE OPERATING to extend my battery life and range time.

Soooooo I figure the Honda will work and will power the charger BUT I figure when I load the cart and its pulling in the vicinity of say 30/40 amps out the batteries THE CIRCUIT BREAKER ON THE CHARGER WILL DROP OUT......... Now if it does so and she pulls back in now n then and stays in long enough to put some battery charge in she will work over the long haul to extend operating time buttttttttttt if she short cycles the chargers circuit breaker and exceeds it or the chargers duty cycles, either the breaker or charger may suffer harm.

My best pure guess is on a hard pull the cart may draw upwards of 40 amps yet the charger red lines at 25 and Im guessing its circuit breaker will open at 30 amps so she should open but if that keeps up over n over n over any actual charge time will be minimal and the charger or breaker may fail from over duty/over cycling grrrrrrrrrrrrrrr I think if the cart were easy cruising on blacktop (say a 25 amp battery draw) my idea may work but stop n go driving at the Florida Flywheelers on that soft sandy ground will overwork the charger MY BRAINSTORM FAILS LOL

So whatcha yall think

PS I have used my Yamaha gas Golf Cart there for years (it can run night n day all week hauling 4 fat a$$es all over that soft sand lol) but just had this idea regardign my electric cart

John T

Get rid of it and get another gas cart. Add gas and go.

Are you sure on the 6 volt batteries, we had one and it was 8 volts, had 6 batteries. Was under the impression the all electric ones were 48 volts. Ours was a 1997 club car, I think...

Gotta go with Bo on this one- your idea just sounds like too much "monkey motion" to me.

Was at a big feedlot once, and they had golf carts where you just pushed the gas pedal, and the engine started and off you went (I dunno, maybe they're all that way- I'm not a golfer)- and when you stopped, it turned itself off. Just about as handy as anything I could think of.

You realize that most portable generators will not power common run-of-the-mill battery chargers?
Doesn't seem to be "common knowledge" except with people who routinely have to deal with battery chargers and gensets. Like with off-grid solar-electric users.

Just about all portable AC generators can only run standard battery chargers at 30-50% output capacity.

The "fix" is, to use a DC based inverter generator, or get a high-end electronic battery charger.

I'm not up to snuff with all Honda genset models, but isn't the 2000 EU an AC rig and not a DC inverter rig? I know the Honda EU2000IA is a DC set.

Main problem is the standard battery chargers get power at 160-170 volts when hooked to AC power. AC grid power IS 170 volts. Portable gensets are usually only 150 volts and thus the problem.

Why not just charge it at night? Seems like a lot simpler. We ran those 36V Club Cars at a campground I used to work at. They maintenance guys would run them for their 10 hour shifts and some of the guys would pull lawn carts with lawn mowers or grass clippings in them. Very rare that they wouldn"t make it the whole day, and if they didn"t it was usually because somebody forgot to plug it in or a battery was bad.

I used to work at a place that had one of these. I can't remember the brand name of it though, but it may have been a Club Car. It had a belt driven starter/generator on it. You push the pedal and the starter/generator acted as a starter. As soon as the motor fired up and ran, the thing was a generator and recharged your 12 volt battery. I do remember that I had to modify some brushes in the thing. The factory wanted about $30 for the proprietary set and I used some that only cost us a couple of bucks.
Personally, I like an automotive type setup better.

I have a 4 HP B&S lawn mower engine driving an alternator to use as a portable charger. I think that would work better than your idea. In your case I would look for a 100 amp alt.

I think the EU Honda's are inverters. Electric golf carts go all day on a charge. Leaving the charger on overnight seems like the best way to keep the batteries charged. If you're going to be running a generator, what's the purpose of having an electric cart? Would be better just getting a gas cart. Dave

Thanks Yall, I will just have to try it and see how the circuit breaker on the charger acts and how the Honda genset performs.

PS I ALREADY HAVE A GOOD GAS CART, push down the pedal it starts n goes PERFECT will run for a week on its 5 gallons of gas. I was just asking for an experiment in case my dear old mother goes to Florida next year and Im stuck with her electric cart to use at the Flywheelers as I dont want to drag 2 carts all teh way to Florida lol

John T

I say try it! Make like a locomotive!
Remember, if you START the day with fully charged batts, when the power pedal is pushed it will take LESS amps,
cause your system will have the voltage up to 40V,... to do the same work.
Even counting the inefficiencies that JDeMaris' experience has shown for battery chargers on gensets;
you are still starting at 40+ insead of 37.5 or so and working downward.
Will depend on te longest continuous run; ie; to the parking lot at night.

SOLAR PANEL!!!


Would work as a roof to furnish some shade too!

Use a NC relay to drop the panel from the circuit when the throttle is pressed to disconnect the panel from the circuit to prevent excess current draw on the panel.

Just a thought.

John there was a guy at Red Power last year doing exactly that.

John T. I run the maintenence shop for the local golf course here in county. I hate to be the one to burst your dream scheme but it may not work as you have it designed! The reason is the golf cart probably has a switch in the system that prevents operation while the charger is connected to the cart. I know Club Car and Yamaha have this feature and most likely EZ-Go will also have it. You may have to try and disable or wire around it. This is to prevent people from driving off and destroying the charger. You need to see if the cart will run with the charger plugged in the cart socket and the charger loaded in the cart so it won't get dragged around. Your cart is most likely a solid state controller system with the charger that is controlled by a circut board inside the charger. The chargers we use on our carts will not stand much vibration/bouncing around before the circuit boards go up in smoke. A state of charge meter would be a good investment for this. The automatic chargers have voltage sensing relays that measure the voltage and start up. The relay has to sense about 28 volts to kick the charger on. Then it turns the charger off at 42-45 volts or a preset number of hours. you may need one of the older EZ-GO chargers that just have a timer knob if the automatic charger won't kick in.
Curios to know if it does work for you, please post results of your effort. One bit of advice; these batteries do not need to be drawn down below 50% charge many times unless you have a deep pocket for replacing them. You would be wise to check the water level in the batteries before doing this much running continously and check all cable ends for tightness because a loose cable will burn the post off of a battery in a few minutes. The Trojan T-105 batteries are now $110 each in my part of the country. Just put a set of 6 in my Yamaha cart in Janurary. Gene Davis

One of the fastest and scariest rides I ever had was in a K-Mart warehouse.
The golf cart was factory equiped with 36V worth of batteries. The controler limited the voltage to the motor at 24V.
The guys in the shop had installed 48V worth of batteries and set the controller to allow 100% of battery voltage to the motor.
That cart would squeal tires on concrete and almost lifted the front wheels.

Toyota stuck a metal skin on a golf cart like that and called it a Prius. I've got one.

Hi John,

Sure it'll work just fine as wired as a 12v system from the genset. Or using the genset to run a external charger.

Another example of a similar configuration would be the battery's drawing 100ahr to run a 115v inverter while at the same time being recharged via solar PV's or a house solar PV array supplying voltage during sunshine.

Both the above examples operate just fine with tripping any of the safety's and the same that the genset will do.

As Gene noted, trying to use the existing charger may be a real challenge if not impossible.

T_Bone

Only problem you got is, if the car is wired correctly, and you plan to use a proper charger, as soon as you plug the charger into the outlet on the cart, the cart wont move.

Two problems with that, in general. Not necessarily with the Honda EU2000 since I know nothing about it specifically.

A house solar-system using a battery, controller/charger, and solar panels often needs supplemental charging via a fuel-driven genset. It is this sort of application where many people using solar discovered that AC portable gensets do not work well with conventional battery chargers. Many test have been done for a work-around. Cheapest fix is a gas-driven DC charger made from an auto-alternator. Also, 10% step-up transformers used with AC gensets.

DC gensets are a different story. The Honda EU might be DC, I'm not sure. If so, it will probably work fine with a low-end charger. If AC, it' won't.

So, there are two potential problems.

#1 - an AC genset not working well with a battery charger.

#2 - Often, the direct DC output from an AC generator is unregulated and trips at 8 to 10 amps. Won't charge a battery with a high demand. "All or nothing" sort of thing.
Not in all cases, but often.

A few tests we ran here:

Portable gensets hooked to a small 12 amp charger.
Note that the Honeywell is the only DC inverter based genset we tested. All others are AC.

Honda EM3800 - max output of 3 amps
Jetman GG1200 generator - max output of 3 amps
Homelite 4400 generator - max outpout of 3 amps
Coleman 1800 generator - max output of 3 amps
Honeywell 2000 inverter - max output of 11 amps

Portable gensets hooked to large AC charger:

Honda EM3800 - max output of 9 amps
Jetman GG1200 generator - max output of 8 amps
Homelite 4400 generator - max output of 9 amps
Coleman 1800 generator - max output of 9 amps
Honeywell 2000 inverter - max output of 25 amps

Portable gensets used with a special electronic
battery charger - Xantrex Truecharge 40 amp ($400)

Honda EM3800 - max output of 30 amps
Jetman GG1200 generator - max output of 28 amps
Homelite 4400 generator - max output of 30 amps
Coleman 1800 generator - max output of 30 amps
Honeywell 2000 inverter - max output of 36 amps

Most golf carts were only 36 volts using six 6 volt deep cycle batteries till about 1999 or 2000. The early 48 volt carts used six 8 volt batteries then came the four 12volt batteries which were a disaster in some cases. Now there are some offered with eight 6 volt batteries to replace the four 12 volts. 36 volt carts are good if used correctly, even the resistor models. Yes,the resistor speed control is old school technology for sure, but there are thousands of them running out there. The solid state controller type carts will go longer on the run time, but the resistor type speed control is far from being dead as folks tend to keep running old golf carts till they just vaporize or disappear. Golf carts are popular in all age groups and for almost any given need.