Battery question, replace?

[marianol]

I just tested the batteries and after a full charge this is what I see in my multimeter.

B1 6.10
B2 6.13
B3 6.40
B4 6.35
B5 6.33
B6 6.38

B1 and B2 have a tap for 12 volts I assume is for the cart lights, it looks like an original tap since it comes from a cable bundle.
Since the cart has a separate 12V battery for the stereo and light bar. I'm thinking of talking this tap out and wiring it to the 12V one this weekend.
Is this a good idea?

Based on what I read B2 and B2 are pretty much dead, unless you guys know some magic I can do to save them

The batteries are Energizer GC2 and the date on them shows 4/15 (looks pretty new to me).
The warranty sticker says 1 year and they are manufactured by Johnson Controls. I will try to see if I can get a replacement but not sure where to start?

If warranty does not fly; should I change those 2 with the same brand or can I mix?

[JohnnieB]

Try charging B1 & B2 with a 12V charger as shown in the attached drawing. You don't have to disconnect them.

I'd give B1 & B2 12 to 16 hours at 10A (adjust time for lower amp output chargers), then remove the 12V charger and connect the 36V charger and give the whole pack a charge, wait 12 hours and check the voltages again. Repeat as required until B1 & B2 are staying within about 0.1V of the rest of the pack.

B4 & B5 could use a boost charge also.

If you have a 6V charger, you can do them individually, otherwise it is in pairs with a 12V charger.

If that doesn't work, replace the two with the same make/model battery.


Definitely move all the accessories over to the separate 12V battery.

[marianol]

Thanks JohnnieB!

Will do and post the results.

[marianol]

ScottieB; followed your advice luckily i had a 6/12 v charger so I went with 6v and charged them individually.
And now all the batts are in the 6.37/6.38 range

I took out the 12V tap out, but the problem I have now is how to actually wire that to my 12v accessory battery since the Neg end is the one that goes to the battery SOC meter in the dashboard (next to the key).

My EE background tells me that I should have the the 36v and the 12v negatives of the Batteries connected like in the attached diagram

But reading the forum it looks like that is a NO GO in this type of application, so I'm not sure how to wire this so I can still use the SOC meter.

[JohnnieB]

Ideally, there would be two electrically isolated circuits, as now shown in your drawing that I edited.

The negative of the battery pack for the drive system and the negative of the 12V accessory battery can be connected together so a single meter can be used to monitor both by switching the positive input to the meter.

For safety reasons, the body/frame of electrical golf carts are not grounded to the batteries and everything is a two wire system.

FLA batteries generate gaseous hydrogen an oxygen, so sparks are a no-no and by isolating the batteries from the cart chassis, the possibility of arcing and/or arc welding is reduced.

[marianol]

Thanks JohnnieB!!

My batteries are now up and running getting 6.3 after a charge so that deal is done.

I fully get it now thanks to the explanation, there is no "chassis ground" on this buggies so is all 2 wires.
Now I will have to rewire the ground coming form the lights, Volt Meter and Key so I can wire the lights on a separate circuit tot he 12v battery per your diagram.

Since my lights are turned on with the Key I think my best bet will be to take them out of there and have them on a separate switch to keep things simple.

[HiTechRedNeck]

2 position Key switch(cart on/lights) has 2 separate switches.
Isolated so you can use key switch for 12v lights and cart.

[marianol]

Originally Posted by HiTechRedNeck

2 position Key switch(cart on/lights) has 2 separate switches.
Isolated so you can use key switch for 12v lights and cart.

Thanks @HiTechRedNeck! I got this wiring diagram.


So one switch is L - B1 and the other is I - B correct?

Edit: Which is the negative (ground) B and B1 or I and L?

[JohnnieB]

Originally Posted by marianol

1. So one switch is L - B1 and the other is I - B correct?

2. Edit: Which is the negative (ground) B and B1 or I and L?

1. No. One switch is I -> B (Main Battery pack voltage) and the other switch is L -> B1 (12V for the lights)

2. There is no ground. Each switch only switches the respective positive wire.

[marianol]

Originally Posted by JohnnieB

1. No. One switch is I -> B (Main Battery pack voltage) and the other switch is L -> B1 (12V for the lights)

2. There is no ground. Each switch only switches the respective positive wire.

Got it! Thanks JohnnieB

If the switching is on the Pos(+) side; looks like I will only have to route a new Neg (-) from the lights to the 12V battery and I can use the original 12 v wiring for the Pos (+)

Will try to rewire my lights this weekend and open a new thread if I got any more questions.

10000x Thanks to both...