Installing a VSR specifically for solar panels

[coopec43]

When I installed the inverter I thought I'd be smart and use a 1/2/both switch so I had flexibility as to where I drew the input power from (House or Starting bank)

That resulted in a a molten negative cable and one of the starting batteries destroyed. I have removed the 1/2/both switch and now plan to charge both battery banks using the alternator and a Victron Cyrix 24V VSR.

Now I am considering using an additional VSR purely for the solar panels. The VSR I am considering is quite reasonably priced and has more than enough capacity. Is that a crazy idea?

[rslifkin]

Personally, I'd replace the switch with 2 switches. An on/off switch for house power, and a 1/2/both/off for starting power selection. That one normally stays on "1", but allows you to easily start from the house bank if something happens to the start battery (including the option of taking the start battery out of the system entirely, rather than just paralleling).

On my setup, I haven't worried about start battery charging from solar. They get charged from the engine alternators, or when shore / generator power is available to run the charger for them. Nothing draws from the start batteries, so I haven't felt a reason to worry about charging them from solar. Self discharge is minor enough that I can't see them sitting long enough to be of any concern.

If anything, I'd use a DC-DC charger to charge the start battery, not a VSR. Otherwise you're likely to end up abusing the start battery depending on absorption time and voltage needs of the house bank.

[Stu Jackson]

Originally Posted by coopec43

When I installed the inverter I thought I'd be smart and use a 1/2/both switch so I had flexibility as to where I drew the input power from (House or Starting bank)

That resulted in a a molten negative cable and one of the starting batteries destroyed.



....................

Without a wiring diagram showing what you did, it would be almost impossible to figure out how you burned up a negative cable.


Was this an inverter or an inverter charger combo?

[smac999]

if you already have a Victron Cyrix VSR between the engine and house battery.

there is no need to add another one. the cyrix will also share the solar between the 2 banks.

[smac999]

Originally Posted by Stu Jackson

Without a wiring diagram showing what you did, it would be almost impossible to figure out how you burned up a negative cable.


Was this an inverter or an inverter charger combo?

probably has his engine cable direct to the start bank, but a small cable between the 2 banks. that could not handle the inverter load when drawing from start battery.

if so should be made bigger because it's also not going to handle a parallel starting load either.

[ItDepends]

Why on earth would you EVER want to power the inverter from the starter battery??? That kind of violates every reason to ever have a separate starter battery. Having a separate starting battery give you assurance you can ALWAYS start the engine, no matter what else happens. Connecting it to house loads (especially an inverter!) destroys that whole design philosophy.

[coopec43]

Originally Posted by Stu Jackson

Without a wiring diagram showing what you did, it would be almost impossible to figure out how you burned up a negative cable.


Was this an inverter or an inverter charger combo?

Thanks Stu

I could only give you a circuit diagram of what I think I did but I don't think that would be much help. I'm out of my depth but there are no auto electricians in town these days (maybe I'll have to wait until I get it into the marina)

It was just an inverter. Thanks

[coopec43]

Originally Posted by ItDepends

Why on earth would you EVER want to power the inverter from the starter battery??? That kind of violates every reason to ever have a separate starter battery. Having a separate starting battery give you assurance you can ALWAYS start the engine, no matter what else happens. Connecting it to house loads (especially an inverter!) destroys that whole design philosophy.

I can't argue with that.


I've decided to carry a heavy set of jumper leads to give me option I may want. (I understand how to use them)

[Uncle Bob]

Originally Posted by coopec43

Thanks Stu

I could only give you a circuit diagram of what I think I did but I don't think that would be much help. I'm out of my depth but there are no auto electricians in town these days (maybe I'll have to wait until I get it into the marina)

It was just an inverter. Thanks

Coop, I have 2 of those switches, one wired to the starter and the other to the house loads. Each switch is connected to both banks, enabling the connection of either load to either bank, or if the need should arise, both banks. Been that way for years and works well.

[coopec43]

Originally Posted by smac999

if you already have a Victron Cyrix VSR between the engine and house battery.

there is no need to add another one. the cyrix will also share the solar between the 2 banks.

Yes I agree with that.

But it concerns me that the yacht could be laid up and the AGM batteries damaged as they are allowed to flatten. Thanks

[coopec43]

Originally Posted by smac999

probably has his engine cable direct to the start bank, but a small cable between the 2 banks. that could not handle the inverter load when drawing from start battery.

if so should be made bigger because it's also not going to handle a parallel starting load either.

YES!! Absolutely!

I've looked at the smaller cable between the battery banks and wondered if it couldn't handle the load. But why would it destroy one of the AGM batteries too? (I've tried to charge it but it won't go over 9 volts which I presume is because one of the cells is dead)

[coopec43]

Originally Posted by Uncle Bob

Coop, I have 2 of those switches, one wired to the starter and the other to the house loads. Each switch is connected to both banks, enabling the connection of either load to either bank, or if the need should arise, both banks. Been that way for years and works well.

Hi Bob

I haven't chucked out my two HD 1/2/both switches as I may wish to use them in future. But right now I'm trying to get the yacht into the water without destroying another $300 battery.

Cheers

[coopec43]

I suppose the obvious answer is to get the inverter going again (in an urgent sense) and then keep my Starting Bank topped up using the 12V/24V battery charger plugged in to the inverter.

[Stu Jackson]

Originally Posted by coopec43

I suppose the obvious answer is to get the inverter going again (in an urgent sense) and then keep my Starting Bank topped up using the 12V/24V battery charger plugged in to the inverter.

What?


You do realize a charger plugged into an inverter is nonsense, right?

[rslifkin]

Originally Posted by Stu Jackson

What?


You do realize a charger plugged into an inverter is nonsense, right?

I agree, but if it's only powered on for occasional use when the boat hasn't seen shorepower or any meaningful engine runtime in a few weeks, it's not so bad. As long as nothing is drawing from the start battery when the engine is off, continuous charging shouldn't be necessary.