Solar Connection 2 Battery Banks

[Gone Gypsy]

Need some help!
I have 3 new solar panels and getting ready to DIY install. The panels will run to a Victron 100/50 controller. Looking at how to hook Victron output to 5 225 Ah AGM batteries wired as 2 separate banks through battery switch. Bank 1 is 3 AGM’s wired neg/neg and pos/pos with the positive of the last battery in the string going to a Cole Hersee M705 battery switch. Same with Bank 2 except only 2 batterys in string. I know this is not the best working setup for multiple batteries but it is how the boat came.

The current Magnum MS2000 Charger Inverter positive DC leg feeds into the Cole Hersee M705 battery switch and connects to both battery banks when the switch is in the ALL position.

This Cole Hersee switch input seems to be the right place to also connect the positive leg off the Vicron controller - right on top of Magnum charger. The Victron negative would go to common neg connector stud.

Is this workable?

I will have disconnects on both panels legs right before the Victron and will have a fuse on the Victron positive output right before the Cole Hersee battery switch.

I will have to rewire later to eliminate the strings in the banks, but just looking to get the solar hooked up with what I have.

Thanks!

[JimsCAL]

Easiest would be to install something like a BlueSea ACR. Connect the solar to one bank. When the voltage on the bank rises, the ACR will close and connect the second bank in and now charge that as well. Will automate the charging of your 2 banks until you get around to rewiring them.

[Tupaia]

From your description it looks like 1 bank comprising a 3 and a 2 in parallel. A diagram might help to understand it.


What is the reason for the 2 banks? you appear to have only singular input sources charger or MPPT.


If you really want 2 banks then feed all the inputs to one bank (primary) and fit a battery combiner between the banks.

[s/v Jedi]

The setup as you propose is functionally correct.

That said, it is a very lightweight install for your boat. I would expect at least busbars to be present, as well as a 24x7 fusebox for bilge pumps etc. and a feed to a breaker panel.

With busbars, you simply give each battery (bank) its own on/off switch and you have a system that allows expansion of connections etc.

[Gone Gypsy]

Thanks guys!
Yes, 2 banks each in parallel.
Why 2 banks is unknown. Legacy issue for me. Boat came that way.

The ‘bussbar’ for each bank is an isolated stud that has a power in leg common/coming from the bank positive going into the battery switch and has a multitude of positive out demand legs under a double nutted stack connection. Single stud ‘bussbar’ for each bank.

Thanks Jedi for the quick functional ok response.
I will proceed to install Victron as feed to the battery switch same as the Magnum charger for now.

Will start work on new battery connections and bussbars for a fall project.

Thanks!

[noelex 77]

Originally Posted by Gone Gypsy

Why 2 banks is unknown. Legacy issue for me. Boat came that way.

Most of the time it is sensible to operate with the two banks in parallel, but electrically dividing the house battery bank into two does have some advantages.

For example, servicing, troubleshooting and equalisation are all easier. It can also be to used to isolate a bad battery in conditions where it may not be practical to do this by physically removing connections.

Ideally you need to be able to run and charge bank one only, bank two only, or both banks together. The best way is seperate on-off battery switches on each bank.