3 strings in battery pack, cross connect?

[Jacotenente]

Looks awfully similar to what I am doing with my three strings. However, folks, I am having something going on that I should be slapped silly for doing. I think I caught the issue early enough not to cause significant damage. Give you a hint...my three Classics are really strong and was doing things that shouldn't be done. On my YouTube channel I explain it...check it out if you want. Oops.

[TomW]

On my YouTube channel I explain it...check it out if you want. Oops.

Frankly, not many folks will go hunt down your YouTube channel so posting a link would work much better.

Just a heads up.

Tom

[CDN-VT]

This looks odd but it's actually quite simple. What has been done here is to start with 2 pairs of batteries. Each wired in the proper "cross diagonal" method. Then each pair is wired together, again in the cross diagonal method.

Notice that for each individual battery, the current always goes through a total of one long link and one short link before reaching the loads.

This method also achieves perfect balance between all 4 batteries and may be easier to wire up in some installations. Many thanks to "smileypete" from www.canalworld.net/forums for this idea.


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

[TomW]

VT;

I get how this works and it is  somewhat sneaky smart. It just makes my head hurt looking at it as a whole.  Once you trace the paths individually it gets more clear.

One situation where more connections makes sense in a way.

Tom

[russ_drinkwater]

How does that work on 12 x 4 volt tubs?

[kitestrings]

Don't you only have a single, series string with the Rolls 4V cells, or have I missed something?

[CDN-VT]

You can do the same with 4Vdc Tubs that are Series /Parallel on trying to increase the Amp Hr's

VT

[russ_drinkwater]

I run two separate banks of 24 volts on separate ergs and panels.
Inverter draws off both banks.

[dgd]

Inverter draws off both banks.

how does that work? Are both battery banks somehow connected to the inverter's DC input?

dgd

[russ_drinkwater]

Yes I run a an isolator switch 4 position. Off, bank 1, bank 2 or bank 1&2 together. When I had the smaller bank of trojans I would run the house on the trojans during the day and switch to 1 bank of the rolls overnight. Now I have the two banks of rolls up and running I found the
2700 amps @ 24 volts did not need any switching between banks. So I just draw off the 2 banks together unless it is really overcast for a long period and then I switch to grid tie and monitor battery health or wait for finer weather.
The overload switch in that link is a tad small at 100amps and dumps out if we use a chip cooker or the like!
Wife is trained up and switches or when necessary, even checks the classics for voltages and soc!
Working on her and the electrolyte levels next!