Battery jumpers and lenghts.

[Jemplayer]

I have a question I cannot get definitive clarity on.

In a series bank of batteries ( 8 RE-B trojans / 48V bank) , the battery jumper (i.e. interconnecting cable) are 35mm2 thick and 30cm long, but between battery 4 and 5 the cable needs to be 1.5 meters long. How thick of a cable should this 1.5m piece be to avoid creating and more resistance between battery 4 and 5?

The same 35mm2 or maybe 50mm2 or even 75mm2 ??

[bcroe]

With cable adequate for the system currents, and no balancing between parallel sections, there is
no need to make the 1.5M heavier. It might be justified if copper losses are excessive. Bruce Roe

[Sunking]

Minimum size requirement depends on the fuse size feeding the Inverter. A 35 mm2 cable is equal to a USA 2 AWG good for 115 amps. So unless your fuse is larger than 115 amps, no safety issue.

[Jemplayer]

With cable adequate for the system currents, and no balancing between parallel sections, there is
no need to make the 1.5M heavier. It might be justified if copper losses are excessive. Bruce Roe

This was my understanding as well, but recently someone argued the point of voltage losses, and that battery 5 onwards would be slightly less, I then became unsure.

So to confirm, there is NO need to adjust cable size in a series bank for longer runs as I described before?

Sunking, your point re max amps are known and noted, inverter is 5kw, fuse is 120amp.

While we are on the subject of wire size (or AWG) and their max amp ratings, is there a table or post on the forum that shows these? And voltage losses at certain lenghts.

[littleharbor]

The spammers seen to have figured out how to get through, once again. Where's the flag tab?

[Mike90250]

The spammers seen to have figured out how to get through, once again. Where's the flag tab?

I see the flag tab, lower right of the post's frame.

I un-approved the post, so the admins can see it and figure out what happened

[littleharbor]

For some strange reason I don't have the flag tab . I'm going to try restarting my computer and see if it reappears.

Restarted , no difference....Strange.

[sdold]

Flagging a spam post is best, but if you're not able to do that, one thing that's helped me is when someone responds with "SPAM!!!". Sometimes when looking through the new posts I'll miss the telltale wording of a spam post, but I never miss that all-caps proclamation. It's the next best thing if you can't "flag" a post for some reason.

[J.P.M.]

For some strange reason I don't have the flag tab . I'm going to try restarting my computer and see if it reappears.

Restarted , no difference....Strange.

Me too.

[littleharbor]

I know where the caps lock key is. Will definitely use it next time.

[SunEagle]

Me too.

Do you now have the "flag" selection on posts?

[littleharbor]

It's back. Whatever was done to remedy , Thanks.

[SunEagle]

It's back. Whatever was done to remedy , Thanks.

I believe our IT department has been tweaking the software. My guess is that we will still find some abnormalities. Feedback from the Members would be appreciated.

[sdold]

...I never miss that all-caps proclamation. It's the next best thing if you can't "flag" a post for some reason.

FYI, this isn't useful anymore (for me at least) because I don't see the first couple of lines of new posts anymore, so flagging the post is the best option.

[Jemplayer]

If we can get back on topic of this thread.

The issue of different cable/jumper length in series banks plagues me. Sunking is it ok to have one or two battery jumpers longer in a AGM or Flooded bank in order to work around a difficult space that does not allow even rows.

will batteries in that bank be equal in charge and discharge? Will the longer piece not create a touch more resistance to that battery and the batteries thereafter?

N.B wire is sized correctly for load. i.e 35mm in this case on a 4kw inverter.

I know in parallel (which you should actually never do in a daily cycling system) dead even cables and correct termination are non neg..!