question

vicky avatar image
vicky asked

Are my AGMs dead or is it the inverter dying ?

Good day,


I need some help to understand if my AGM Batteries are dead...

Reason why I am asking is we are not sure if our inverter is dying, or if Batteries are flat or both...

We had a bit of strange "electronic" smell the other day, minor but noticable, unfortunately we werent able to locate the source.

Batteries are 2 Eliminator Ultra 6V 192Ah in series, three years old, usage between 3 and 5 month/year.

Sitting charged and disconnected during winter, no usage, where we get down to - 45°C.


Batteries are charged by a Smart Solar MPPT 100/50

Parameters set according battery manufacturer:

Absorption 14.12V

Float 13.45V

Equalization 14.55 (Disabled as not recommended)


Monitoring by Smart BMV 712

If required we recharge by a Generator powered 120V/12V 50A Charger with AGM settings.


Now the stoty:


Couple days ago the batteries were fully charged 100% SoC, float status

over 12 hrs we consumed 61 Ah, SoC showed 69%, Voltage was down to 11.83V @ basic load of 3.3A by Starlink.


Then the fridge drawing 10-13Amps tried to start, voltage dropped to 11.52 and Inverter (120V/1.5kW) , which is supposed to work from 10.6V-14.5.V, switched off.

Not only switched off, but started the audible alarm at 5 a.m., the other day it was at 2 a.m.

The only thing to avoid this is running the genset before going to bed and top up the batteries...


In the past sometimes we went down as far as 55% w/o issues and inverter did start. Unfortunately I don't have detailed records from those days.


The battery statistics by BMV 712

deepest discharge -89Ah

avg discharge -70Ah

cummulative Ah drawn 11.721Ah

discharged energy 143.3kWh

charged energy 159.8 kWh

total charge cycles 31

synchronizations 141

min batt Voltage 10.66

max batt voltage 14.73


Any feedback highly aprecciated

I am already close to buy a Multiplus II and two new batteries, these wake up calls are anoying

AGM Battery
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1 Answer
kevgermany avatar image
kevgermany answered ·

Seems to be the batteries. They can be tested by a battery retailer.

If you're sticking with lead, consider lead carbon. Much better life, small price premium. Also consider a bigger set.

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