Battery question/ balancing...

[CDCustoms]

Hi all, so I installed Six brand new lead acid 8V batteries into my 48V (In series) last night and also installed Sergio's posted idea for passive voltage bypassers one on each battery of course in an attempt to start these things out right for a LONG life. Tested the voltage on each to compare at full charge and found the following.... This is with a MODZ Max48 charger...
(EDIT*) This is without rest but is this still a big spread in voltage?
1) 8.78 Volts
2) 8.55 Volts
3) 8.50 Volts
4) 8.68 Volts
5) 8.55 Volts
6) 8.63 Volts

Anyhow, as you see it's all over the place. My questions is can this be expected from brand new batteries? Does it take a few charging cycles to become balanced? What are your thoughts?

[Swan]

I would wait for them to be at rest before drawing any conclusions

[CDCustoms]

Well..... I let them rest a good 12 to 14 hours and they are still just as wonky with voltage across each.... So again, does it just take time for them to balance? Just curious...

[scottyb]

Can you do an equalizing charge with that machine?

[ThreeCW]

Originally Posted by CDCustoms

Anyhow, as you see it's all over the place. My questions is can this be expected from brand new batteries? Does it take a few charging cycles to become balanced? What are your thoughts?

Originally Posted by CDCustoms

Well..... I let them rest a good 12 to 14 hours and they are still just as wonky with voltage across each.... So again, does it just take time for them to balance? Just curious...

My experience with my Trojan T-125 6 volt 240 amp hour batteries is that there was very little voltage difference between them (0.07 volts) when new (after my third charge) and there is very little voltage difference between them today (0.07 volts again). This is 2.6 years and 306 charges later. I am not running voltage balancing electronics on them.

What make and model batteries do you have?

By comparison, your batteries have a un-stabilized voltage difference of 0.28 volts. I am not sure if this is much to worry about ... as it may not fall into the "wonky" category . Give your battery pack a few more charges, let you voltages stabilize for 24 hours and then see what you get.

Scotty, I am not sure if brand new batteries will benefit from equalization - the electrolyte "should" be homogenous and plate deposition of sufates "should" not be a concern either. That being said, equalization should not hurt either.

For your reference, my voltages are:

July 16, 2018 Pack voltage = 51.7 volts Hour Meter = 79.3 hrs
Stabilized voltages after 3rd charge (~20 hrs after charging)
Bat 1 = 6.43 volts
Bat 2 = 6.49
Bat 3 = 6.49
Bat 4 = 6.49
Bat 5 = 6.42
Bat 6 = 6.49
Bat 7 = 6.47
Bat 8 = 6.43
High to Low Difference = 6.49 - 6.42 = 0.07 volts

Feb 10, 2021 Pack voltage = 51.5 volts Hour Meter = 196.4 hrs
Stabilized voltages after 306th charge (10 days after charging) with 0.1 hrs / 1/4 mile of cart use since last charge.
Bat 1 = 6.40 volts
Bat 2 = 6.46
Bat 3 = 6.47
Bat 4 = 6.45
Bat 5 = 6.42
Bat 6 = 6.43
Bat 7 = 6.45
Bat 8 = 6.43
High to Low Difference = 6.47 - 6.40 = 0.07 volts

[CDCustoms]

So I have a ModzMax 48 and I wouldn't suspect that it is capable of balancing batteries itself throughout an entire charge cycle. The batteries I purchased are from Battery Plus+ and are 8 volt Duracell Golf Cart and Scrubber deep cycle batteries SLIGC8V. (Capacity 20hr: 165AH). I have read that since these are sold west of Mississippi they are made by Johnson controls and not DEKA/East Penn. Not sure that should matter to much as one would think they have the same manufacturing standards. BUT I could be wrong...that happens about once every 10 years or so Don't get me wrong, I'm not worried by any means but more curious how it is some manage to obtain such consistent balancing. I told my wife I was thinking about AGM batteries after these crap out in what I hope is a good 4-5 years and shared the price of approx. $2400 bucks. She said NOTHING...I just got the 1000 yard stare and was pretty sure she wanted to cut me.

[CDCustoms]

Originally Posted by scottyb

Can you do an equalizing charge with that machine?

Curious, do you have any of the 1050w chargers in stock with a crow foot adapter/cable? If so I might just return my MODZ 48.

[Briboy]

Originally Posted by CDCustoms

I just got the 1000 yard stare and was pretty sure she wanted to cut me.

Buying a golf cart was her idea,,, And I get this a lot!!

[NismoGriff]

Originally Posted by Briboy

Buying a golf cart was her idea,,, And I get this a lot!!

We bought our cart because we went seasonal at a campground in 2020. It was her idea and I ran with it!! We decided not to return to a seasonal site for this coming season and after I sold the deck I built and the shed she said, WE ARE KEEPING THE GOLF CART!!