Solar causes charger to fail

[flightlead404]

I have a Mastervolt 12/50-3 charger which charges my house (2xLifeline 210AHr AGM) and start batteries (all new 10/2020).

This unit performed flawlessly since I bought the boat (4/21) until I installed solar (9/21).

I have 3x 210W panels in series to an Epever Tracer 6415AN MPPT charger.

Since installing the solar most days when sitting on shore power the charger goes into a failure mode by mid-morning. It does not happen on cloudy days, at night, or early morning/late afternoon, which leads me to thinking that the solar is the culprit.

Both charger and controller are configured in the default AGM settings.

Solar controller is wired to the main negative buss and to the COMM post on the house battery switch.

Any clues?

[HeywoodJ]

The Epever manual only shows voltages for the charging profile, not times, so this is a bit of a guess.

The Mastervolt is probably seeing the battery reach bulk/absorption voltage as a result of the solar. It then tries to drop back to float (Mastervolt has a couple of stages in here as it tries to work out how long it should stay at absorption, it’s not a fixed time). When it can’t go to float because the solar is holding the voltage at absorption for longer than the Mastervolt thinks is required it faults.

You might be able to set a custom absorption time in the Epever software, don’t know, otherwise probably simplest to just turn off the Mastervolt when the sun is out.

[Uncle Bob]

Originally Posted by flightlead404

I have a Mastervolt 12/50-3 charger which charges my house (2xLifeline 210AHr AGM) and start batteries (all new 10/2020).

This unit performed flawlessly since I bought the boat (4/21) until I installed solar (9/21).

I have 3x 210W panels in series to an Epever Tracer 6415AN MPPT charger.

Since installing the solar most days when sitting on shore power the charger goes into a failure mode by mid-morning. It does not happen on cloudy days, at night, or early morning/late afternoon, which leads me to thinking that the solar is the culprit.

Both charger and controller are configured in the default AGM settings.

Solar controller is wired to the main negative buss and to the COMM post on the house battery switch.

Any clues?

With that much solar for a small bank you should never need shore power anyway. Try it without shore power connected for a month or so and get back to us.

[thomm225]

Originally Posted by Uncle Bob

With that much solar for a small bank you should never need shore power anyway. Try it without shore power connected for a month or so and get back to us.

Yeah how about it!

I have usually hooked up 115 watts of solar and haven't used shore power in maybe 8 years. It's charging two 220 ah 6 volt golf carts batteries at this time.

Btw solar is my only power source as my outboard doesn't have an alternator but my next one will just in case

[flightlead404]

Originally Posted by HeywoodJ

The Epever manual only shows voltages for the charging profile, not times, so this is a bit of a guess.

The Mastervolt is probably seeing the battery reach bulk/absorption voltage as a result of the solar. It then tries to drop back to float (Mastervolt has a couple of stages in here as it tries to work out how long it should stay at absorption, it’s not a fixed time). When it can’t go to float because the solar is holding the voltage at absorption for longer than the Mastervolt thinks is required it faults.

You might be able to set a custom absorption time in the Epever software, don’t know, otherwise probably simplest to just turn off the Mastervolt when the sun is out.

That is the hypothesis I'm working on as well. I was thinking of programming the Epever to simply match the Mastervolt profile. I'll see how to accomplish this.

[flightlead404]

Originally Posted by Uncle Bob

With that much solar for a small bank you should never need shore power anyway. Try it without shore power connected for a month or so and get back to us.

Planning on it lol. Splashing Friday and continuing south

420 AHr but planning on adding a 3rd to bring me to 630 Ahr.

But I have a fridge, freezer and an electric head

[smac999]

Originally Posted by HeywoodJ

The Epever manual only shows voltages for the charging profile, not times, so this is a bit of a guess.

The Mastervolt is probably seeing the battery reach bulk/absorption voltage as a result of the solar. It then tries to drop back to float (Mastervolt has a couple of stages in here as it tries to work out how long it should stay at absorption, it’s not a fixed time). When it can’t go to float because the solar is holding the voltage at absorption for longer than the Mastervolt thinks is required it faults.

You might be able to set a custom absorption time in the Epever software, don’t know, otherwise probably simplest to just turn off the Mastervolt when the sun is out.

no other charger faults when this happens. it's very normal to have multiple charging devices. when the mastervolt goes to float if the solar is still in bulk, it will just output 0a untill the voltage gets lower then then the set float voltage. then it will kick back in with current.

the only thing I can see causing a fault warning is if the voltage is way wrong. like over 15v.

[flightlead404]

Originally Posted by smac999

no other charger faults when this happens. it's very normal to have multiple charging devices. when the mastervolt goes to float if the solar is still in bulk, it will just output 0a untill the voltage gets lower then then the set float voltage. then it will kick back in with current.

the only thing I can see causing a fault warning is if the voltage is way wrong. like over 15v.

I do see high voltages from the solar. Reconfiguring to more closely match the Mastervolt charging profile should help. Will update next I'm on shore power.

[macman4190]

My Mastervolt would go onto fault during float because the solar float was higher than the Mastervolt float. Issue went away when I matched voltage for all three stages. Most of the time, I leave the Mastervolt off. If I have a rainy/cloudy stretch, I will switch to Mastervolt.