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Author Topic: Build battery 24v bank with exide l2v320 marathon  (Read 8907 times)
fc
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« on: June 03, 2012, 05:34:07 PM »

Hi there i have now a 24v 200ah with 2 12v agm batteries in series.
I received a set of 24 batteries exide l2v320 marathon, they are 3 years old but had been on floating voltage 99% of the time, so even after  2 months disconnected they  are showing 2.12 volts. for me they seem ok and good option to replace my 200ah 12v batteries.

here they are:


I have some doubts on how to build  my batt bank i means i don't have physical space to do a row of 12 batteries in series so i would need to do 2 rows of 6 batts but then i wil have a longer connection between the first 6 and the last 6 bats , any problem with this ?

now solving this issue of a row with 12 batts or 2 rows of 6 in series  i would  need to wire the 2 sets of 12 bats in parallel ..


So this is what i would like to do but no physical space:



This what how i will have to do



Suggestions ?? tips  ? opinion on these batteries are welcome..











 
« Last Edit: June 03, 2012, 05:37:24 PM by fc » Logged
martin
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« Reply #1 on: June 03, 2012, 06:35:18 PM »

Here's chapter and verse - this is well worth following! - http://www.smartgauge.co.uk/batt_con.html
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Justme
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« Reply #2 on: June 03, 2012, 08:14:00 PM »

The second one is better as each string has its own cable to the central point so loads & charging will be shared equally between the banks.

I would change the other end & use two seperate cables of the same length. Plus add in extra cables at the end or you might as well just use one cable between each cell in the complete bank.

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« Reply #3 on: June 03, 2012, 09:50:40 PM »

Method number 3 in Martin,s link is as good as it gets without going overboard.
                         It is important to keep all the link wires exactly the same length to the main junctions.ITs years since i got advice on here in Navitron on how to hook up batteries and i believe it was Justme and Martin who put up the links.I eventually went for a bigger voltage,(120volt  ,10 x 12volt x 100ah batteries x 2strings,all wired in series and i thought that being wired in series would eliminate any unfair treatment for some batteries but for some strange reason number 2 to the right of the top string and number 9 to the left of the bottom string failed on two occasions,I replaced the batteries and one one occasion swapped them around but those positions came up several times as failure points.I eventually got my hands on forklift batteries and they are trouble free if you remember to keep them topped up.
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« Reply #4 on: June 03, 2012, 10:19:54 PM »

This is what our 24V bank looks like at each end. I'd have thought two of these with matching cable lengths would do it  bike


* Batt 1.JPG (66.27 KB, 500x333 - viewed 783 times.)

* Batt 2.JPG (59.32 KB, 500x333 - viewed 827 times.)
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biff
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« Reply #5 on: June 03, 2012, 11:15:19 PM »

Immaculate ,,prestine batts,,,,,,,,
                   How i wished mine looked like that,,it would actually be a horrible sin to put a load on those hysteria
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fc
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« Reply #6 on: June 03, 2012, 11:54:34 PM »

Hi thanks for all info can I use only one cable by batt or should I keep both ?
What are your opinion on these bats ?
My current location for the bAts is a bit closed but I will open a hole in top near roof to extract air and A ventilation grid near the floor, never had. Issue with h2 with my current bats , but I will move from 2 12v agm to 24 x2v so better to had some vent, later I wil add a h2 sensor to start Exhaust air in case the h2 concentration rises..
But agm batts should only vent when overcharged , right ?


Thanks
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Justme
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« Reply #7 on: June 04, 2012, 08:43:57 AM »

I agree with Elanors first pic (it matches the right hand side of my pic).

But the second pic I have doubts about.

You have gone to all the effort & expense on having cables for each connector on each cell but on the take off end you have basically cut corners by using the short link.

There are two possibilities:-

1, that the terminals are internally connected in a balanced way in the cell so it does not matter which terminal you use.
(but then why have two terminals in the first place)

or

2, they are not balanced evenly & the external double cable are needed for balance.

In 1 you might as well just use extra thick single cables for all the interconnects in 2 you need matched cables at all points.
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« Reply #8 on: June 04, 2012, 11:02:49 AM »

in your photos, is that where they're going to be ?

you really want them up off the floor if it's concrete.. (it looks like it?)



they'll get cold there and that will hurt there capacity / life expectancy
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fc
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« Reply #9 on: June 04, 2012, 11:12:45 AM »

Hi, no this is only a temporary space where i'm checking them & planing connections ..
The space where they will be is so small that i don't have space for testing  and they will be on top of  a wood palette.
 
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fc
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« Reply #10 on: June 05, 2012, 12:10:27 AM »

Hi there today i decided to upgrade to 48V system and so i will have to connect my 24v bats all in series as my physical space is very limited i will have to put the bats in a 2 "floor" runing along the walls....
like this


not to different o what was it 24v only one thing worries me  is that one of the conectios i will have at least 40cm cable, any issue with that ?

regards
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knighty
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« Reply #11 on: June 05, 2012, 12:15:17 AM »

can you use thicker cable for the long run?  or double up and have 2 cables for each one ?
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fc
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« Reply #12 on: June 05, 2012, 12:22:30 AM »

yes i can choose the cable i want,  in fact that is also a question what would be the cable size for that corners connections as i have small coper plates for interconnect the bats only these corners need cable ...
other big doubt i have is that i need to connect both connectors on the bats or only 1, i can't find any reference to that on the batt documentation...
i read on another place that the 2 connectors are only for redundancy in case one fails or need replacement... (but not clear)...

Regards
 
 
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« Reply #13 on: June 05, 2012, 08:26:20 AM »

they'll get cold there and that will hurt there capacity / life expectancy

The colder they are the less capacity, but the LONGER their life expectancy is.  Hotter bats = more capacity but less life expectancy.
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knighty
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« Reply #14 on: June 05, 2012, 11:01:25 AM »

they'll get cold there and that will hurt there capacity / life expectancy
The colder they are the less capacity, but the LONGER their life expectancy is.  Hotter bats = more capacity but less life expectancy.

I was thinking with there lower capacity, they'd be drawn down to a lower % of charge ?
(compared to if they weren't cold)
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