Genius 4 amp charger

[Blackwoodz]

On my Swift 200 I've got 3 batteries. 1 27 for starting and 2 27s in series for the tm.
I had a Genius 2 bank when I aquired the boat so I installed it to charge the 2 tm batteries. I bought a single 4 amp noco to charge the starter battery.
The two bank works awesome and maintain 13-14 volts depends in it's cycle but keeps batteries in great shape.
The single noco never shows above 12.8 volts.

Is this charger defective? I've swapped batteries around to different chargers and the results stay the same.
I've been holding off sending it in hoping it was okay.
It's warranty is no issue but just hated having to box up and send it off.

Looking for others that might to have a similar noco and get their thoughts.

Thanks

[CatFan]

What does the battery measure 8 hours or more after unplugging the charger?

[Blackwoodz]

I haven't measured any of them. I just know the single bank is not showing the higher voltage as the dual bank is.
And I've swapped the batteries through all three leads and any battery on the single noco only shows 12.8 after it's been charged for a few days.

[Casslaw]

My Noco states in the manual that it charges to 13.8 volts before it turns green and enters a “maintenance” mode. I would check your voltage at the battery while charging to see what voltage it is charging at, then after the light turns green (does it turn green?) check voltage then, and after 24 hours to see if it’s a charger or battery issue.

[Blackwoodz]

I've seen 13.4 when it's unplugged a few moments and plugged in...but when it turns green it's at 12.8v

[billnorman1]

I'd expect the charger to start at approximately 14.2 VDC and taper off to about 13.8. 4 amps isn't very much to recover a discharged battery.

[Lou r Pitcher]

I haven't measured any of them. I just know the single bank is not showing the higher voltage as the dual bank is.
And I've swapped the batteries through all three leads and any battery on the single noco only shows 12.8 after it's been charged for a few days.

The newer charger after reaching maintenance mode does not apply any voltage until the battery voltage falls below the threshold value.

So your single bank charged battery showing always after a few days a value of at least 12.8V suggests it is a fully charged battery. If after being disconnected overnite as CATFAN inquired, it still shows a similar voltage, your battery is indeed fully charged.

Seems the question is on why the two bank charger constantly is applying a float voltage and not shutting off....perhaps it is simply because that particular older charger's charging algorithm is to finish applying a continuous float voltage? If so, no harm......it just is not very energy efficient as many of our newest chargers are today.