Charging 8 volt golf cart batteries

[Rene T]

My golf cart has six 8 volt batteries. When I go to FL shortly I may have to have them charged. My charger only has the option for charging 6 volt or 12 volt batteries. Will I be able to charge my batteries by either using the 6 volt or the 12 volt setting?

 

[Mark_K5LXP]

Nope. 6V isn't enough to even think about it, and 12V would absolutely overcharge. If it's a "smart" charger it would trip out or otherwise give up, sensing the voltages aren't right. If it's a dumbe charger, on 12V it would likely overload and trip after some period of minutes. 8V batteries are generally charged as a bank of 24 or 48V, I'm not sure I've ever seen a charger for 8V but no doubt there's probably one out there.

If you have AC power for a standalone charger, why wouldn't you just power the onboard 48V one?

Mark B.
Albuquerque, NM

 

[Rene T]

Nope. 6V isn't enough to even think about it, and 12V would absolutely overcharge. If it's a "smart" charger it would trip out or otherwise give up, sensing the voltages aren't right. If it's a dumbe charger, on 12V it would likely overload and trip after some period of minutes. 8V batteries are generally charged as a bank of 24 or 48V, I'm not sure I've ever seen a charger for 8V but no doubt there's probably one out there.

If you have AC power for a standalone charger, why wouldn't you just power the onboard 48V one?

Mark B.
Albuquerque, NM

I was just thinking that would take forever to charge the batteries. Also some onboard chargers will not work if the voltage in the batteries are below a certain level.
There is a Repair guy that comes around who has modified one of his chargers so that it will charge no matter how low the voltage is in the batteries.

 

[Lou Schneider]

I was just thinking that would take forever to charge the batteries. Also some onboard chargers will not work if the voltage in the batteries are below a certain level.
There is a Repair guy that comes around who has modified one of his chargers so that it will charge no matter how low the voltage is in the batteries.

The refusal to charge batteries that have low or no voltage is to protect against trying to charge a battery with one or more shorted cells. If your lead acid batteries have sat with a low charge or completely discharged for any length of time they've likely sulfated and are toast.

 

[Gary RV_Wizard]

There is a Repair guy that comes around who has modified one of his chargers so that it will charge no matter how low the voltage is in the batteries.

Handy but also risky if one of the batteries has a shorted cell. A battery fire or even explosion is possible.

 

[Gary RV_Wizard]

I was just thinking that would take forever to charge the batteries.

It takes just as long or longer to get all 6 8v batteries charged if you do them one at a time. And you have to disconnect the batteries to use an 8v charger (they are wired in series in the cart)

But if you want one, there are plenty of 8v battery chargers available on Amazon or in golf car stores.

 

[Mark_K5LXP]

Right, if they're that low and have been sitting, they may be toast anyway. But a "long time" for an onboard but correct charger would be better than no charge attempt at all. My "charge anything" charger is an old sears portable car charger that has a transformer and some diodes in it, with an autotransformer in the line cord. So I can dial an amp with the autotransformer and it will pump a nominal charge into whatever it's connected to. For "flat" gel cells I use a lab/bench power supply with adjustable volts and amps. For those I'll wind the voltage up to 30+V for a 12V battery but the current limited to less than an amp. It can sit like that for hours not drawing anything but sometimes they'll wake up and start accepting current. Once they start acting like a normal battery a regular charger can take over. Often they're still toast but no harm in trying. A fixed output 18-24V supply (like even a laptop switching supply) with a ballast (like a turn signal bulb) in series can work well as a "charge anything" supply to bring up arbitrary state batteries, enough that once they're above "dead" a regular charger can take over.

Mark B.
Albuquerque, NM

 

[Rene T]

Thank you everyone . To be truthful this is not for me but I have friends with 8 volt batteries. I just wanted to know what recourse we had if the problem came up. We purchased a new golf cart last spring so mine are good for a few years.

 

[Kirk]

We purchased a new golf cart last spring so mine are good for a few years.

But if it has 8V batteries it still has the same problem unless you use the golf cart's charger.

 

[Gary RV_Wizard]

Or unless the new cart has 8 x 6v batteries instead of 6 x 8V.

 

[Tulecreeper]

It takes just as long or longer to get all 6 8v batteries charged if you do them one at a time. And you have to disconnect the batteries to use an 8v charger (they are wired in series in the cart)

But if you want one, there are plenty of 8v battery chargers available on Amazon or in golf car stores.

You could just disconnect 3 from the rest and use a 24v charger for the two 24v banks, right? Less charge time than 6 individual 8 volt batteries.

 

[Tulecreeper]

But if it has 8V batteries it still has the same problem unless you use the golf cart's charger.

A golf cart comes with its own charger?

 

[Rene T]

But if it has 8V batteries it still has the same problem unless you use the golf cart's charger.

Mine has a smart charger and it is plugged in as we speak

 

[Mark_K5LXP]

In the days of yore golf carts had offboard chargers because the only thing that could source that much current had a big transformer in it.



Very unsophisticated, the Lesters usually had a ferroresonant transformer to operate in a constant current mode, and often no more than a mechanical timer to shut it off. I used the transformer out of one of these along with a homebrew monitoring circuit to charge my EV (FLA) for years. Nowadays with switched mode supplies you can get pretty much any voltage and power point you might want you can hold in your hand, so easily integrated into battery equipment. Nicer to batteries too.

Mark B.
Albuquerque, NM

 

[Lou Schneider]

A golf cart comes with its own charger?

They may be external but usually the charger has to see enough battery voltage to energize a relay before it connects the charger to the output. This neans the connector is de-energized even if the charger remains plugged into the wall. And provides protection against charging a battery with one or more dead cells. So you could say they had some rudimentary logic before "smart" became popular.

 

[Tulecreeper]

They may be external but usually the charger has to see enough battery voltage to energize a relay before it connects the charger to the output. This neans the connector is de-energized even if the charger remains plugged into the wall. And provides protection against charging a battery with one or more dead cells. So you could say they had some rudimentary logic before "smart" became popular.

You may have misunderstood my reply to Kirk. My response was with regards to his post that says, "But if it has 8V batteries it still has the same problem unless you use the golf cart's charger." Which I assumed meant that he was saying that golf carts come with their own built-in charger. For example, I have owned several boats, all of which I added an onboard charger to, but it was either an extra option at the time of purchase or an aftermarket item. But all of them were removable, if necessary.

 

[Domo]

How do they charger their batteries now?

Why not get a new charger - Amazon... $35

 

[John From Detroit]

Ok six 8 volt batteries means you are either 24 or 48 volt (Likely 48)
the golf car should be designed to charge the entire Bank.
If this is the case it matters not if the batteries are 8 6 volt, 6 8 volt or 4 12 volt save for the current delivered.. I'd go with the slower setting (most likely 12) if you are using the golf car charger.

If you are using a stand alone charger.. You will need a custom made one.

 

[Gary RV_Wizard]

A golf cart comes with its own charger?

It's an EV, right? And most such have a charger, whether built-in or external. It's the fuel tank filler and every vehicle needs one of those.

 

[Ernie n Tara]

The 48V chargers re standard item for old xarts, see Amazon.

Ernie