Full River Battery Change

[Cessna172]

Greetings,

I am in process of replacing my UB batteries with 3 Full River DC105 grp 27 and 1 Full Throttle FT965-27) (2 House, 1 Starter, 1 Thruster) in my 2017 Cutwater28.

Given that both the UB's and the Full River/Throttle are AGM, will it be necessary to make changes to my battery charger?

Thanks,
Gary

 

[glider4]

If both the batteries coming out and the batteries going in are AGM and have similar AmpHr ratings then I believe you should be ok with out any changes to the charger or solar controller. That’s assuming the battery charger and solar controller were set up correctly in the first place.
BTW, we have all Group 31 sized batteries in our 2017 C-28. The original factory installed Universal Power UB121100 batteries were also Group 31 sized.
Is there a reason you’re going to the smaller (and lower AmpHr rated) Group 27 size?

 

[Cessna172]

Thanks for the response. The charging numbers are very close between the UB's and the Full River. The biggest difference is with the Charging Voltage. The UB's have a charging voltage of 14.6 - 14.8 volts, while the FullRiver is 14.3 - 14.5 volts.

I chose the group 27s because I truly believed the UB121100 was a grp 27... Did I make a big mistake?

 

[glider4]

The UPG UB12110 batteries that the factory installed in our C-28 measure 12.97 x 6.89 x 9.55 inches which is the typical Group 31 size.
Generally, Group 27 batteries measure 12.0625 x 6.8125 x 8.875 inches. They usually weigh a few pounds less than the Group 31 batteries from the same manufacturer and average a 10% lower AmpHr rating. For UPG, the UB121000 Group 27 battery is 5 pounds lighter and 100 AmpHrs compared to 110 AmpHrs for the Group 31 sized UB121100 battery.
We had the Group 27 sized batteries on our 2009 R-25 Classic. If they will fit, I’d recommend the Group 31 over the Group 27 size just to get the higher AmpHr rating typical to the Group 31.
As far as charging voltage, I have my Victron Energy SmartSolar 100/30 set to 2 which delivers 14.4 volts in Absorption and 13.8 volts in Float. Those middle of the road settings seem to work for most non-spiral AGM 12 volt batteries.

 

[Cessna172]

Thanks again glider4!

I do not know how I came to believe the UB121100 were grp 27. Somehow the idea got in my head and influenced my purchase.

I talked to the Battery Dealer today and they are going exchange the grp 27 Full Rivers for the 31's. I just dread lugging these incredibly heavy things back to the dealer and then back to the boat again... Better now though than after they were installed.

 

[shontm]

Thanks again glider4!

I do not know how I came to believe the UB121100 were grp 27. Somehow the idea got in my head and influenced my purchase.

I talked to the Battery Dealer today and they are going exchange the grp 27 Full Rivers for the 31's. I just dread lugging these incredibly heavy things back to the dealer and then back to the boat again... Better now though than after they were installed.

Are you happy with the Full River batteries? I'm thinking of doing the same on my R-29.