Kodak OG 5.48 inverter undercharging 4x12V100AH

[NewbyKodak]

Hi,

I have a newly installed Kodak OG 5.48 inverter and 4x12V100AH Vision 6FM100Z-X batteries in series.

Firmware
Main CPU version: 47.00

I have been struggling to charge the batteries past the default float voltage.

The default AGM battery type settings (float = 54, Bulk=56.4V) have not been able to give a full charge and the battery voltage quickly drops during load-shedding to 50V and then slowly starts tapering. I expect that this will happen from the float voltage without the big initial drop.

I have now upped the float to 55.2 and the charging current to 30A (initial 10A). Am I missing the obvious?

 

Any advice would be appreciated.

 

 

Edited May 24, 2022 by NewbyKodak

[Coulomb]

11 hours ago, NewbyKodak said:

Firmware
Main CPU version: 47.00

Not in my collection, unfortunately.

11 hours ago, NewbyKodak said:

I have been struggling to charge the batteries past the default float voltage.

That could well be the premature float bug.

11 hours ago, NewbyKodak said:

4x12V100AH Vision 6FM100Z-X batteries in series.

100 Ah is a bit light for a 5 kW inverter. You should not use too much power during load shedding.

11 hours ago, NewbyKodak said:

the battery voltage quickly drops during load-shedding to 50V and then slowly starts tapering.

The sudden drop is expected, as the battery goes from being charged to being discharged, but a full battery (with a light load) should drop to some 51.x volts. 50 V (12.5 V per 12 V module) indicates a middling state of charge.

11 hours ago, NewbyKodak said:

I have now upped the float to 55.2 and the charging current to 30A (initial 10A).

It would be better to set the timed absorb ("Bulk charging time") setting to about 60-90 minutes instead. Otherwise, you risk eventually over-charging your battery. This should be setting 32 on your inverter, or a suitably named option on your monitoring software (if any).

Quote

and the charging current to 30A (initial 10A)

Usually, charging current in amps should be about 15% of the capacity of the battery (in Ah). So that would be 15 A. I would round that up to 20 A.

 

Edited May 25, 2022 by Coulomb

[NewbyKodak]

Thanks Coulomb,

That is very helpful. I don't seem to have a "Bulk charging time" setting.

Looks like it is also possible to accomplish the same using the equalization function.

Would the following work?

Battery Equalization
Equalization : Enable
Time    :  90
Period  : 5 days
Voltage : 56.4V
Timeout :  120 min

Regards,

 

 

 

 

 

[Coulomb]

4 hours ago, NewbyKodak said:

I don't seem to have a "Bulk charging time" setting.

That's odd.

4 hours ago, NewbyKodak said:

Would the following work?

...

Period  : 5 days

Yes, that would work, but I'd change the period to 1 day, so you'll get the benefit every day, not every fifth day.

[NewbyKodak]

Thanks,
I update my settings and set the period to 1 day. 

There is no setting for the start time. I waited a day and eventually manually kicked off the equalization. Does the count down to the next run start from the last equalization run?

And lastly, the voltage dropped back down to the float voltage within about 15 minutes after 90min @ 56.4V, is this considered normal?

 

[Coulomb]

4 hours ago, NewbyKodak said:

Does the count down to the next run start from the last equalization run?

Sorry, no idea.

4 hours ago, NewbyKodak said:

the voltage dropped back down to the float voltage within about 15 minutes after 90min @ 56.4V, is this considered normal?

Yes. It's immediately in float mode after the end of absorption, or indeed after timed absorb if you have that feature. But it would usually have a "normal" absorb stage before that, so equalising (different to timed absorb) is in addition to the "normal" absorb stage.