Balanced Charging X's 4 6V Batteries

[Smitty77]

As I've recently started a campaign returning to basics on the care and feeding of my soon to be replaces X's 4 L16's - I have a follow up question.

I've confirmed proper wiring to yield parallel/series, with appropriate and good quality cables.

It was the placement of the Magnum Charger and MidNite Controller charge cable feeds that does not match my research on obtaining balanced charging.

Iota has a nice (Diagrams, makes it easy for a back to basics sanity check!) write up on balanced vs non balanced charging.

My current Magnum and MidNite charge feeds are in a 'non balanced' method. However, when I was getting help here and elsewhere on trying to save my battery bank. I took several multi meter voltage readings of the full bank, and the four individual batteries. And noted. less then a tenth variances in the voltage.

Iota does talk about Amps vs Voltage in their diagrams. So please forgive this question. Does practically balanced voltage at each battery while under charge, equate to balanced amps too?

With a bank of 4 6V batteries vs say 6, 8, etc. - what is the recommended 'Best Practices' for obtaining balanced charging?

TIA, and best to all,
Smitty

PS: OK to say reading too much into this, and not to worry about it...

[MEXICOWANDERER]

It is unforgiving -- utterly.

Taking a mill file to a battery "L-Pad" then to a terminal, to insure both a absolutely flat made a significant difference in terminal to L-Pad interface temperature. Getting the mounting pad flat on the Trace 4024 was challenging. They were concave. A use friend loaned me a mill cutter with a 1/2" arbol hole and will no small amount of effort I dressed the pads.

A vise, a large mill file or bast(a)rd if the surface is rough can really flatten the irregularities on a lug.

9,000 watts is a lot of energy...

[theoldwizard1]

MEXICOWANDERER wrote:
I IR shoot the entire bank after 400+ amp recharging for >20 minutes.

At that rate, any misalignment between the face of the terminal and the battery cable end will WELD the dissimilar metals together ! :B

[MEXICOWANDERER]

The FREE Lifeline battery PDF download has pages of correctly assembled series and paralleled batteries. More batteries and more series configurations than you can imagine.

The connection diagram is valid for all types of batteries not just AGM.

[Boon_Docker]

"I believe that you're referring to the two diagrams that "red31" posted above your earlier post."

Yes, the first diagram (on the left) before the edit.

[pnichols]

Boon Docker wrote:
The diagram above will not work with GC-2 (6 volt) batteries.

I believe that you're referring to the two diagrams that "red31" posted above your earlier post.

The left diagram above your earlier post represents four (4) 12 volt batteries connected in parallel in a balanced way.

The right diagram above your earlier post represents eight (8) 6 volt batteries connected in series-parallel to makeup four (4) "12 volt batteries" connected in parallel in a balanced way. (Notice the little black line at an angle in each black outline box - that outline box represents a couple of 6 volt batteries interconnected in series.)

Connecting batteries together in a "balanced way" is not Rocket Science. All it means is that the total wire length (regardless of what wire size is used) going all the way around the loop from each battery's plus terminal to it's minus terminal is the same length for each battery. With a balanced setup, this "same loop length" for each battery will be the identical for every battery whether the battery bank is being discharged while feeding the RV's total electrical load or being charged while being fed by the RV's charging equipment.

The object is for all battery system cabling voltage drops (regardless of cabling gage size used) from currents going to/from each battery to be the same - as seen by each battery.

Balancing the battery bank this way is of course external balancing ... and does not ensure that internal battery construction and chemistry maintains balance at all times internally between the cells within each battery during the life of the battery.

[BFL13]

Almot wrote:
Forget Iota diagram. It is not your situation because it shows 4 batteries in parallel.

What you have is 4*6V batteries in series-parallel, you may consider it to be two 12V batteries in parallel.

ISTR Mr Wiz likes to do four 6s the other way, with two pairs in parallel and then series the two "big 6s", but can't remember why he likes that.

[red31]

^^ imagine what ya see as one 12v batt being 2 6v or 2 serial sets of 3 x 2v cells in series.

[Boon_Docker]

^^
The diagram above will not work with GC-2 (6 volt) batteries.

[red31]

IMO it is easier to see the balance this way!


http://www.smartgauge.co.uk/batt_con.html

[Smitty77]

Almot wrote:
Forget Iota diagram. It is not your situation because it shows 4 batteries in parallel.

What you have is 4*6V batteries in series-parallel, you may consider it to be two 12V batteries in parallel.

Yes the diagram is not what I'm running with. But the concept of balanced charging would be the same(?).

As my interconnects were disconnected, I laid them out and measured, and the two longer runs were 3" difference. (Never knew that by just eyeballing the S curved cable while on top of the batteries:)!). I also looked over how the shop had single crimped the two cables they made, not impressed with the workmanship. So, with the new bank, I now have two short 12" and two long 15" cables coming from Genuinedealz. They shipped yesterday.

And another observation, is that with only X's 4 batteries in my bank, the connection points of the charge sources is fine. However, I believe (And could be wrong?) that if I had X's 6 or X's 8, etc. That then Iota diagram would come into play, with the charge points being the middle batteries of the bank.

For anyone who reads this thread in the future, please correct me if I'm wrong and 'balanced charging' only applies to parallel?

TIA, and best to all,
Smitty

[Almot]

Forget Iota diagram. It is not your situation because it shows 4 batteries in parallel.

What you have is 4*6V batteries in series-parallel, you may consider it to be two 12V batteries in parallel.

[red31]

Smitty77 wrote:

2oldman wrote:

Using 2oldman's image as an example.

The Charger attachment points are not shown.

charging 'points' are shown, they are the same as discharging 'points'.

why would one look at 4 batts in parallel when ya got 2 in parallel?

[MEXICOWANDERER]

Negative. Done correctly, I have less than .4 volt TOTAL DROP end to end at maximum load. The parallel bridge cables are done at one end the same end.

The batteries have "L" pad posts. I used a mill file to establish absolutely parallel full face conductivity. When mating surfaces are 100% contact, full load breakdown is minimal. I IR shoot the entire bank after 400+ amp recharging for >20 minutes.

[theoldwizard1]

MEXICOWANDERER wrote:
As the owner of 24, 2-volt cells I can tell you the "issue" is amplified at the ends of 12 cell strings.

Do you rotate the position of the cells in your battery string ?