Ideal Battery Bank Wiring

[Hoghead]

I assume this is not the first time this has been asked but I have searched and cannot find a diagram

I have 6 x 6V Trojan batteries and need to wire these into a single 12V bank. I can think of a couple of ways to do this but there must be an optimum way

Can someone please post a diagram

Thanks in advance

[Stu Jackson]

Golf Cart 6V Battery Wiring Golf Cart batts re-positioning & wiring diagrams

[DeepFrz]

Trojan has wiring diagrams on their website.
Battery Maintenance | Trojan Battery Company

[Hoghead]

My installation is a bit more complicated as there are 6 x 6V batts into a single 12V bank.
All the diagrams I see are for 4 x 6V

I understand the series/parallel connections in order to get the 12V but which is the best way to accomplish this when 6 batts are involved

[Hoghead]

Is this optiomal

[ontherocks83]

Originally Posted by Hoghead

Is this optiomal

By my math that's the only way to do it.

[Hoghead]

did it per the yellow diagram as I need to leave Fiji - hope it is the right decision

[Lars_L]

The total length of cables to one pair of batteries should be the same for all.
I.E.
Pair 1.
The cable between the plus bar and battery plus pole 0.5 m.
The cable between the two batteries 0.2 m.
The cable between battery minus pole and the minus bar 0.3 m.
Total cable length 0.5 + 0.2 + 0.3 = 1.0 m.

Pair 2.
The cable between the plus bar and battery plus pole 0.4 m.
The cable between the two batteries 0.2 m.
The cable between battery minus pole and the minus bar 0.4 m.
Total cable length 0.4 + 0.2 + 0.4 = 1.0 m. (the same as pair 1)

Pair 3.
The cable between the plus bar and battery plus pole 0.3 m.
The cable between the two batteries 0.3 m.
The cable between battery minus pole and the minus bar 0.4 m.
Total cable length 0.3 + 0.3 + 0.4 = 1.0 m. (the same as pair 1 and 2)

If you from other calculations have come to that you should have 70 mm² cables, then the cables between the batteries and the bar would have been enough with 25 mm², but put 35 mm².

Each big consumer has its own fuse. I.e. the starter engine need a 150 A fuse, but it should have a fuse. The electrical distribution panel can have a 40 A fuse. Fuses of type MIDI would be enough for the most installations.

With this configuration you can disconnect on battery pair for i.e. maintenance charge, while you live on the other batteries.

If there should be a short circuit in one cell, the fuse to that battery pair will blow, and you will not notice it.

[BriaF]

I agree with Lars_L
The wiring to each 12v cell or battery should
be the same length
If 12v batteries then each should have it own
positive & negative leads & all should be the
SAME LENGTH
If you parallel them with only 1 positive &
negative lead for the whole bank then some
Will get less than others

[Liunatic]

If I read that right, does that give you 12v and 660 amp/hr, or am I missing something

[Lars_L]

Yes, this configuration gives a 12 V system with 660 Ah capacity. (Not A/h)

[rwidman]

Originally Posted by ontherocks83

By my math that's the only way to do it.

You can wire any even number of six volt batteries in this configuration. Want more capacity, add another pair. Each pair of six volt batteries is wired in series, creating a single twelve volt battery (in two separate cases).

While much has been made of having equal length cables, it's more important that the cables have a high enough capacity. This is a situation where a few more dollars spent on heavier cables will pay off.

[sailcrazy]

HogHead, I rebuilt the 12vDC system on our Taswell 43 back in 2002, and installed 6-Trogen T-105s (6v) watered batteries for power. I used a scheme very similar to Lars L's drawing. I set it up so I have 3-12v "batteries". Each 12v (+) is connected an On/Off switch. That sw then goes to a common bus, also with an On/Off sw, then to a house fuse, and on to the dist panel. The 12v (-) all go to a common bus. The system allows me to isolate any one "12v battery from the system, or to remove all 12v power with a single sw. My alternator output and my solar and windgen feed the common bus, but my 3-legged battery charger is connected to each "12v Battery" individually. Its been in use now for 13 years, works as I had hoped, allows me to isolate/remove a bad battery when I need to, and allows me to monitor each "12v battery" via the individual monitors. FWIW

[sailcrazy]

PS....I forgot to mention, I also use a 4th battery (not a deep cycle), for engine and genset starting only. It is recharged via the main bank, via a Balmar Duo-Charger or via the genset alternator. It is completely isolated, but via a parallel switch I can connect the main bank to the starter batt if needed.

[ontherocks83]

Originally Posted by sailcrazy

HogHead, I rebuilt the 12vDC system on our Taswell 43 back in 2002, and installed 6-Trogen T-105s (6v) watered batteries for power. I used a scheme very similar to Lars L's drawing. I set it up so I have 3-12v "batteries". Each 12v (+) is connected an On/Off switch. That sw then goes to a common bus, also with an On/Off sw, then to a house fuse, and on to the dist panel. The 12v (-) all go to a common bus. The system allows me to isolate any one "12v battery from the system, or to remove all 12v power with a single sw. My alternator output and my solar and windgen feed the common bus, but my 3-legged battery charger is connected to each "12v Battery" individually. Its been in use now for 13 years, works as I had hoped, allows me to isolate/remove a bad battery when I need to, and allows me to monitor each "12v battery" via the individual monitors. FWIW

That's pretty interesting. Thanks for the input. I'm going to have to look into that.