MultiPlus-II 12/3000/120-32 and SmartSolar Charger MPPT 150/45 not fully charge the batteries

[Charris]

I have 3 225Ah batteries that after a few months the maximum I can draw from them is 50-70 ah. This is the 4th set I’m replacing in a 2 year period without finding the reason of why this is happening. Various electricians checked and could not find anything.

What I have noticed is that the batteries are not fully charged when i use them of the shore power, i,e I consume 30Ah and when im back and connect the shore power I the batteries are charged upto 99.5% and gradually loses ah. The charger is set also on Sustain mode. What I have noticed is that when I connect the shore power the voltage goes very quicly to the absorption voltage after the bulk and stays there without charging my batteries 1-5w and just covering my current consumption (fridge, electronics). I have made 2 tests and from the 675ah I can draw between 40-60 now.
[I have 3 225Ah batteries that after a few months the maximum I can draw from them is 50Ah before going under 12v.

Any help will be appreciated.

pdf|attachment](upload://iRtM3QmjtIDFb4TucCWMuP6Qgdu.pdf) (1.5 MB)

[Ludo]

As #5 famously said : i need input

Is a smartshunt installed ?

What type of batteries

Settings of mp and mppt chargers

[Ludo]

@Charris

The charger is set also on Sustain mode

So you set solar and wind priority.

How high is your sustain voltage ?

[Charris]

Here is further info. I have everything in pdf format but cannot figure a way to upload the file.x 225ah powervolt agm batteries
Yes, there is a smart shunt

There are 3

Here are the settings of the mppt:

[Ludo]

Please shut off battery monitor in multiplus, and post the settings of the smartshunt.

[pwfarnell]

@Charris

225ah powervolt agm batteries

Sounds like chronic undercharging resulting in sulphation. An absorption voltage of 14.2V or 14.3V seems low, I would expect 14.5V but float of 13.9V is high, but at least 13.6V for sustain is not as low as typical 13.2V. How are you ending absorption, ideally tail current at perhaps 1% of battery pack capacity. As well as info requested by @Ludo do you have a battery datasheet and what are the MPPT expert settings.

[Charris]

Here is the battery charging info:

Here is the MPPT expert settings:

The current SmartShunt is fluctuating between -30 - +40w:

To simplify everything I could disable the sustain mode and turn off the solar if you prefer.

[Ludo]

No, not necessary to make these changes.

But, alas, the settings of the smartshunt are still missing

[Charris]

Here are the smartshunt settings:

[Ludo]

Ok, charged voltage in the shunt should be 0.2v LOWER then in the chargers for synchronisation.

Pls also reset SoC to 30%.

And please set absorption time to FIXED in the mppt ( and mp ? )

As written before, disable the battery monitor in the mp, then trigger the mp to switch off the s&w priority and start a full charge cycle.

[Charris]

I have done the following, disabled battery monitor in MultiPlus, on MPPT change it to fixed, on Smartshunt set the charged voltage to 14.25 and set the SOC to 30.
The MPPT was just producing the energy needed for my boat (fridge and electronics) and was not putting anything to the batteries. Next I turned off the power to be boat and turned it back on in order for the multiplus to reset. I also tuned on the “Charge batteries to 100%” as it was on sustain. That triggered the Multiplus to go to Bulk for a few minutes, and now to absorption at 14.25v but without putting any energy on the batteries (W) ~3w. The MPPT now is on Float and produces 0w as it sees the batteries with 14.22v . next step is to set the multiplus on Fixed charging. Ill let you know

[Ludo]

If your batteries flip from 13.9 to 14.2 volts with a few Ws, your batteries are DEAD.

[Charris]

there are 8 months old batteries and is the 4th set in a 2 year period…
I have set the charged mode on Multiplus on Fixed and im still getting the same results, going to bulk for a minute or so then to absorption but no W are getting to the batteries. Below is a screenshot of my VRM

[Ludo]

I can only repeat : these batteries are DEAD, but you should have checked your system before installing the 3. set of batteries…