Golf Cart Batteries - Gotta Love 'em

[Zebrafive]

Just curious, have you tried a desulphating battery charger? I've brought several batteries back from the dead with one of those. Even one with what appeared to be a shorted cell.

What model is your charger? A desulphating charger is on my "wish" list

[kevin37b]

Yes ,Jinman , that bad battery is taking the whole system down . As a result the good batteries will not charge as they should . You are a fine contributor on this site .

[jinman]

Yes ,Jinman , that bad battery is taking the whole system down . As a result the good batteries will not charge as they should . You are a fine contributor on this site .

Thanks for the compliment, Kevin.

Yes, if you have a battery with extremely high internal resistance and put it in series with three other batteries like a 48V DC cart, the whole system is doomed to fail. Just the simple resistive load imbalance means that the high resistance battery will drop most of the battery charging voltage applied to the string. The perfect system would have equal voltage drops on each battery and a sustained charging current during recharge of about 10 amps. The charger may supply higher current in the beginning, but the sustained current should be about 10 amps so the battery electrolyte does not boil away. I am thinking of rigging four small digital voltmeters across each battery so I can measure charging voltage drop and determine if the batteries are balanced while charging and also discharging/driving the cart.

I also think the term 'desulfating chargers' is something of a misnomer. From my research, the expert opinion seems to be that you can prevent sulfation of new batteries or lightly sulfated batteries. However, heavily sulfated batteries are not going to respond. So, if you have fresh batteries and use a desulfating charger, you will greatly extend the battery's life. However, restoring old and heavily sulfated batteries is pretty much voodoo science. I certainly could be wrong, but I've read a lot of stories on both sides of the issue, and I choose to be skeptical.

[jinman]

I use a 12V DC/AC inverter, with a constant AC load to test individual batteries. Set up a test bench and monitor battery voltage over time. Say two hours with a 100 W load. That will tell you a lot about their real condition.

Tim, do you just use a 100 watt light bulb? That's a very doable test setup with common parts that are easy to find.

[DIXIEDOG]

What model is your charger? A desulphating charger is on my "wish" list

This one works very well at desulfating batteries, I've used it to bring back my deep cycle batteries in my bass boat before

Schumacher SSC-1500A Ship 'n Shore SpeedCharge Charger with included battery clamps : Amazon.com : Automotive


My boat has an onboard Stealth charger that splits my outboards alternator voltage to charge my 4 batteries while I'm running and it also has a Dual Pro AC charger for plugging in when I get home but they do nothing for a sulfated battery....if I have any with problems I use my cheapo charger prior to replacing them. I've brought back several with it so far.

[tcartwri]

Tim, do you just use a 100 watt light bulb? That's a very doable test setup with common parts that are easy to find.

Yup, that's exactly right. Adjust the load to suit your needs.

[smilinjak]

Jinman have you thought of using a four position rotary switch with one meter to monitor the batteries each in turn? Would this serve your purpose and still allow space on the dash?
Smilinjak

[BigE_]

What model is your charger? A desulphating charger is on my "wish" list

I have the BatteryMinder. Forget the model, but I got it off Amazon for about $100. It does wet, gel, and AGM at 2, 4, 8 amps, plus it does the desulphating.

I got it especially because it can do the AGM cells I use on my trailer and computer UPS.

[jinman]

Jinman have you thought of using a four position rotary switch with one meter to monitor the batteries each in turn? Would this serve your purpose and still allow space on the dash?
Smilinjak

I did think of that, but there's a problem. The normal way to wire a switch is with a common ground and then use the switch to select positive inputs. That works great for batteries in parallel, but since these batteries are in series, the connection would read progressively higher voltage for each position:12v-24v-36v-48v. It also would not be simultaneous monitoring of each individual battery. I have located a small LED digital voltmeter that can be mounted easily in the golf ball wells on the dash of the cart and read out constantly. Of course, I'll have to wire a separate positive and negative wire for each meter and include a switch so they can be turned On/Off. It should be a fun project to build.

BigE: I looked at the 48v BatteryMinder and it seems okay, but a bit expensive at $179. They said in their website that you could use your regular charger and then hook up the BatteryMinder. My question is why won't the BatteryMinder just replace the charger? It's probably a really good product, but if it is advertised as a charger/maintainer, then I want it to replace the golf cart charger completely. Too much stuff is too inconvenient for technology challenged people like my brother to deal with.

[aczlan]

I did think of that, but there's a problem. The normal way to wire a switch is with a common ground and then use the switch to select positive inputs. That works great for batteries in parallel, but since these batteries are in series, the connection would read progressively higher voltage for each position:12v-24v-36v-48v. It also would not be simultaneous monitoring of each individual battery.

How about a DP4ST switch such as http://www.amazon.com/Rotary-Switch-.../dp/B001PNMC2K. Then you can switch both ground and hot at the same time.

Aaron Z