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Hi everybody, after using victron products now for over 12 years I now joined the community. I have got a question regarding the wiring in a 24 volt system made up from 6 x 12 volt 265 Ah batteries. I:would like to balance each pair of serial connected batteries but also all three banks of 24 volt. How many balancers do I need and how should I best do the wiring?Wishing a Merry Christmas to everybody!
Best wishes from Sweden
Thomas
Further to @M.Lange perhaps also photo to inform the diagram.
I’m assuming it is 3 parallel banks of two batteries in series.
Please include the bus bars and midpoint connections in the diagram.
Probably Wort adding:I have set up with Bus bars and know the wiring with one balancer ... however, as I understand this set up only balances each bank of the serial connected batteries (or am I wrong) ... and I would like to balance both, banks and serial connected batteries ...
Do I need 4 Balancers?
Can you give us a simple wiring schematic of your system?
Thanks a lot for your swift reply! I can attach a wiring diagram tomorrow. So far some pictures below. The system is combined AC DC off grid. The DC load is an extra heating system. The wiring seems to look confusing, however, With this set up I have all data online. 4 mppt solar chargers are connected.
I believe that in this configuration you only need one battery balancer, certainly not four.
Does this match your setup (though it would appear you still need to add the midpoint links)?
From: https://www.victronenergy.com/upload/documents/Datasheet-Battery-Balancer-EN.pdf
Hi @warwick, yes, that is my battery setup. As I understand in this diagram all three banks are controlled in their serial connection. Can’t I also balance the three banks between each other? Or is this not necessary? As I have six batteries of 265 Ah I thought one balancer would not be strong enough and I wan to run them paralle, which should be possible according to the handbook. But how do I wire this up? I also understood that the midpoint wiring is here only for the BMV 702 which I do not have. Am I wrong here? Do I have to wire the six batteries like this in any case?
Ps. Midpoint wiring is only for balancing or monitoring. This can be used with the Balancer or BMV.
To answer you a little more fully @Spjutmo - this is not actually your setup in the diagram above because your setup does not have the midpoint links that allow you to balance the banks with one another.
If you want to do that as well, then I guess add the midpoint links but leave the balancers as they are. @Daniël Boekel (Victron Energy Staff) is the guru here and he may chime in.
My gut tells me there is no point balancing the banks with one another - the balancers are there to ensure the batteries in series are balanced for as long as possible to maximise the life of each virtual 24V battery by equalising the voltage on each of the physical 12V batteries.
In this case, it is probably better to be more granular (one balancer per two batteries) than less (midpoints and a single battery balancer). But I could be talking out of my arse now, so Daniel should really advise.
Dear all, here comes now the simple wiring schematic of the battery part including the balancer set up as it is now. All wiring has the same length and the main cabling is all 90 mm2. As I understand with this I balance each bank itself but not the three banks. Any advice? I sense I need a fourth balancer ... - do I?
All the best from Sweden
@M.Lange and @warwick : wishing you a Merry Christmas as well
Here is the attachment
Hi everybody, I have done more research ;-) ... and found this: https://www.victronenergy.com/upload/documents/Wiring-Unlimited-EN.pdf Page 21 gives the answer .... As I now understand, with the three balancers in place I wouldn’t need the midpoint wiring. If I had only one balancer the midpoint wiring would be the answer. Is this correct?
Yes that looks right to me. I saw this in your very good diagram too. Makes perfect sense.
