Battery link leads

freddyuk

Is there a diagram for connecting 48v battery bank of 8 x 220ah/12v so 4 in series x 2 banks in parallel with balancing leads? Also for a 48/10000/120 victron Quattro what size cables are appropriate for the links between batteries? Lengths can be short. Advised link to inverter is 2 x 50mm cables up to 5m length.

Cariboocoot

Re: Battery link leads

First question: where are you getting 220 Amp hour 12 Volt batteries? Just checking. Such a thing would be really large and typically that is the Amp capacity of a 6 Volt battery. That's a big bank: over 10kW hours @ 50% DOD.

Wiring is the same for any two parallel strings, the strings simply have more batteries in them. Cable should be large enough to handle the maximum expected current which is basically the maximum capacity of the inverter divided by the minimum operating Voltage. Or consult the installation manual because they usually have the best recommendations for installation (especially for keeping the warranty valid). Links between batteries also must meet this maximum current spec. The cables to the inverter may need to be larger in order to keep the V-drop at maximum load to a minimum (not as much of a problem with a 48 Volt system as with a 12 Volt one).

AuricTech

Re: Battery link leads

Cariboocoot wrote: »

First question: where are you getting 220 Amp hour 12 Volt batteries? Just checking. Such a thing would be really large and typically that is the Amp capacity of a 6 Volt battery. That's a big bank: over 10kW hours @ 50% DOD.

While I don't know the source of the original poster's batteries, I do know that our host sells Universal AGM 12-volt batteries with up to 250 Amp-hour capacity (C/20).

Cariboocoot

Re: Battery link leads

AuricTech wrote: »

While I don't know the source of the original poster's batteries, I do know that our host sells Universal AGM 12-volt batteries with up to 250 Amp-hour capacity (C/20).

Yup. 154 lbs. each. Like I said: really large.
I just felt it necessary to check the specs due to the Amp hours coinciding with the standard GC2's; people do get confused about these things and it's best to make sure we're dealing with the right numbers.

freddyuk

Re: Battery link leads

Cariboocoot wrote: »

Yup. 154 lbs. each. Like I said: really large.
I just felt it necessary to check the specs due to the Amp hours coinciding with the standard GC2's; people do get confused about these things and it's best to make sure we're dealing with the right numbers.

Batteries sourced from UK supplier. They are flooded wet lead acid not AGM's. So will require and have maintenance and recovery if things go wrong! Site is a small processing plant using some heavy amps for maybe 2 hours in a day. Hopefully low DOD will extend lifetime. 10KW PV should keep things topped up. Maximum load maybe 6-7 kw/240v peak via Victron inverter with generator backup if required.