6 volt battery?

[Brianinsocal]

I will be changing out my old 12 volt's to Two 6 volt on my travel trailer. A couple of questions though. I believe I need to run a 2/0 wire between the negative and positive of the 6 volt batteries. They are 225 Amp hour batteries. The wire going into my trailer from the batteries are 6 to the panel and 8 to the slideout. Will I have to up the size of the wires?

2x6VoltinSeries.gif


Also on the picture where the leads say "to +12v and To Ground " are those the same terminals that I hook up the solar charge controller to?

Thanks for your help.

[Sunking]

OK you are making the right move progressing from 2 parallel 12's to 2 series 6's for your battery configuration. So good job there.

I assume you meant a short section of 2/0 AWG connecting the two batteries right? Inter-Cell Cable?

If correct, answer is pretty much whatever size conductor you want providing a couple of conditions are met. One of the conditions the Inter-Cell cable between the two 6 volt batteries must be at least as large as the conductors connected to the battery term post. So if your trailer uses #6 AWG, then the Inter-Cell cable must be at least #6 AWG or larger.

So the answer is yes, you could use a 2/0 AWG if you wanted to as it is larger than #6 AWG minimum requirement. You CANNOT use anything smaller than a #6 AWG

[lkruper]

OK you are making the right move progressing from 2 parallel 12's to 2 series 6's for your battery configuration. So good job there.

I assume you meant a short section of 2/0 AWG connecting the two batteries right? Inter-Cell Cable?

If correct, answer is pretty much whatever size conductor you want providing a couple of conditions are met. One of the conditions the Inter-Cell cable between the two 6 volt batteries must be at least as large as the conductors connected to the battery term post. So if your trailer uses #6 AWG, then the Inter-Cell cable must be at least #6 AWG or larger.

So the answer is yes, you could use a 2/0 AWG if you wanted to as it is larger than #6 AWG minimum requirement. You CANNOT use anything smaller than a #6 AWG

Thanks, it is posts like this that keeps me coming back to this forum.

[Brianinsocal]

Thank you Sunking!

[Sunking]

Thank you Sunking!

You are welcome. I have no problem over sizing the Inter-Cell conductor size.

There does become a point when over sizing components becomes pointless and just pouring money in a hole. I am not going to say 2/0 is too much overkill or not because cost are minimal and more than safe. What I can tell you is the only real measurable benefit of over sizing in this case is: It allows you to upgrade the 6 AWG cables connected to the term post for distribution without having to also change the Inter-Cell cable. Additionally I can tell you will never connect 2/0 cables to the Term Post because assuming these 6-volt batteries are GC batteries have a capacity of about 200 AH. That means you would never need to draw more than 100 amps from the battery and 6 AWG cable in Free Air with 90 degree insulation max current limit is 100 amps. 2/0 under same conditions is good for 300 amps and no way can you demand 300 amps on a small golf cart battery.

I can see up sizing to say #2 AWG could prove beneficial someday down the road. For example let's say you are finding too much voltage drop from the battery to the point of use. You would need to up size the trailer conductors to lower voltage loss.

2/0 is good, but 2/0 is not required as indicated in your OP. You over killed it by a factor of 3. You can sleep good with that knowing it will never be a problem. Just use at least a #6 AWG dictated by what is connected to the Term Post of the battery. 2/0 meets and exceeds the minimum requirements. Under peer review inquiry you get a PASS.

[SunEagle]

I think what can be misleading is that even though the battery system is rated 225Ah that is a 20hour rating.

As Sunking mentions you may sometimes (but rarely) draw even 100amp so that #6 wire is plenty big. Most other times your amp draw will be down around 10 to 15 amps. Much higher and you will deplete that battery very quickly.

[Brianinsocal]

Thanks Suneagle.

Sunking .

Thanks for the PASS! I should know better!! When I ordered the Trojan T-105RE batteries at the battery store the salesperson/kid told me I needed a 2/0 awg cable to interconnect. Luckily the batteries won't be here until Wednesday and I did not purchase that cable. I will buy the correct cable as per your helpful guidelines. I have learned my lesson and will ask here first.

Thanks again for all your invaluable help. Especially the heads up on the 6 volt over 12 volt batteries from a previous thread.

[SunEagle]

Thanks Suneagle.

Sunking .

Thanks for the PASS! I should know better!! When I ordered the Trojan T-105RE batteries at the battery store the salesperson/kid told me I needed a 2/0 awg cable to interconnect. Luckily the batteries won't be here until Wednesday and I did not purchase that cable. I will buy the correct cable as per your helpful guidelines. I have learned my lesson and will ask here first.

Thanks again for all your invaluable help. Especially the heads up on the 6 volt over 12 volt batteries from a previous thread.

You are welcome.