Question about ambiguity in Victron balancer installation notes

[Hogheavenfarm]

Good Morning frenz,

I have a question about the instructions given in my Victron 24v Balancer
The system is 24v with 2s2p arrangement of 12v 200ah AGM batteries. The Victron manual lists these notes for wiring the balancer in.

(2) In case of series-parallel connection, the midpoint interconnecting cables must be sized to at least carry the current that arises when one battery becomes open-circuited. - In case of 2 parallel strings: cross section 50% of the series interconnecting cables. - In case of 3 parallel strings: cross section 33% of the series interconnecting cables, etc.

(4) Use at least 0,75 mm² to wire the negative, positive and midpoint connections (in this order). Additionally, if in your application it is needed to comply with UL, also fuse these wires near the batteries with a 10A fuse suitable for DC current (e.g. Littelfuse ATOF series automotive blade fuse in combination with an inline fuse holder).

I plan on using 12g wire for the connection leads to the batteries, with 10a blade fuses.
The battery interconnecting cables are 2 AWG

The way note #2 reads, I assume the “midpoint connecting cables” are the battery interconnects and not the Victron leads to the “center” connection at the battery serial cables, because I would then need 4 AWG leads to the Victron balancer, and there is no way that would fit the terminals on the Victron.

Also note #4 says I could use 18g or thicker for the “midpoint connections” which in this particular note would be the Victron leads, not the battery serial connection cable.

Am I understanding this correctly?

 

[LakeHouse]

Yes, I think you're interpreting that correctly. Midpoint interconnecting cables are for carrying a portion of the load on the battery, so they need to be 'large'. The wires in note 4 are for carrying the balance current, so they can be pretty small in comparison.

 

[Skypower]

That’s not well written. The load current within the battery group is a totaly different issue from the balancer. I don’t know why they even bring it up. The balancer only needs to be wired and/or fused for what it is capable. Why they call for a 10 amp fuse when it can’t balance over an amp is strange. I’d be fusing much smaller, say 3 amps per lead.
You could be overkill with 12 gauge but at least you won’t accidentally break it while working.

 

[Hogheavenfarm]

Thanks all, I couldnt understand the apparent contradiction between the two notes, My last balancer instructions were quite simple and easy to follow, this one threw me.

 

[Minnichds]

Anyone have any pictures on how they did the fuses? I was able to find two 6 circuit blade fuse holders and I’m about to finish wiring on a 48V system with 3 balancers. I went with blade fuses because that’s all I could find but I’m curious also if anyone went another route.