2016 C-26 Replacement Batteries

[koedding@comcast.net]

I've searched TugNuts regarding battery replacement for our 2016 C-26.  Three of the four AGM batteries are the original.  So I guess I need to consider myself fortunate that we haven't had any battery issues up until this past Fall and that was with the engine battery. We drystack and the solar panels are exposed to the sun for the better part of the day.  So, I've been under the assumption that the batteries are being trickle charged while in the stack. We have a generator and the battery setup is 1: House (Starboard side); 2: Engine and 3: Thruster (Port side).  I had the repair shop check the batteries and they said they needed to be replaced since they weren't holding a charge. What I find odd is the readings on the battery bank voltmeter.  Both 1 & 3 are at 12.31 volts and 2 is at 10.59 volts.  So it's obvious that battery 2, Engine, needs to be swapped out. I'm wondering if I should defer replacing 1 & 3?  What are recommended battery type and sources of supply?  The repair shop is recommending Interstate DCM0100L batteries.  

 

[trailertrawlerkismet]

Just a heads up and you may already be aware of this, if you have agm make sure replacements are agm or if you switch to all flooded wet cell be sure to reset your battery charge/inverter to the proper setting.

Jim F

 

[scross]

Second what Jim said about not mixing AGM and flooded.
I was looking at almost the exact same situation when we bought our 2017 C-28 in November. New engine battery but the other three original batteries were six plus years old. All four batteries were the Universal Power UB121100 deep cycle 110 AH batteries. I bought another UB121100 from Home Depot ($204) and moved the one year old UP engine battery to the house bank.
Now I just need to buy some high CCA dual purpose batteries for the engine and thruster. Leaning towards two X2Power AGM batteries with 1150 CCA. They are made by NorthStar and while described as deep cycle are really dual purpose batteries.
Normally the Universal Power batteries would not be my first choice for the house batteries but it didn’t make sense to me to throw out the one year old UP engine battery.
BTW, just testing the resting voltage is not enough to tell you battery health. They need to be tested under load.

 

[GaylesFaerie]

mmm, a resting voltage of 12.3 doesn't sound good. That's roughly 80% of full. If it were me I'd buy all new batteries. Another issue to be aware of is what happens when old batteries and new batteries are charged together as would happen if you had an ACR. If the ACR closes combining the battery banks, then the old batteries will cause the new ones to degrade faster. Why? The charger will see one big bank and one voltage across all the batteries and charge accordingly going from Bulk to Absorption to Float. The problem occurs as the newer batteries (less internal resistance) will charge faster than the old (more internal resistance) and hit their optimal voltage sooner, but the combined voltage will still be lower than optimal because the bad battery is in the mix. With the ACR closed (i.e. battery banks combined) because a charging voltage is present, the charger will continue charging until the mix reaches the optimal voltage resulting in the new batteries being overcharged. It probably won't hurt anything in the short term but over the long term you will get a shorter battery life out of the new ones. If battery batteries/banks will be charging together as one large bank because an ACR is involved, its best to replace all batteries so they charge equally as one. HTH, Gary

 

[Cutwater28GG]

best place I have found for replacement universal agm's is amazon as shipping was included. they come and go in stock.

the key for easy swap is finding them with the same terminal type.

 

[scross]

Per Gavin’s comment, the terminal type does matter for easy install but other terminal types can be made to work with adapters.
Just installed the X2Power AGM Group 31T 1150 CCA battery as the engine battery yesterday. It has a male threaded 8 mm terminal stud. That required getting an 8mm to 6mm brass terminal adapter for the smaller cables and a new 18” 2/0
AWG yellow cable to connect negative terminals of engine to thruster batteries. The positive terminal didn’t need any adapters and connecting the three cables to it was straightforward.
The four year free replacement warranty on this battery made the extra steps of connecting the negative terminal connections worthwhile to me.

 

[mikey]

Al you just replaced the ending battery? I suppose it is compatible with the other 8A27 batteries. My engine battery is 8A27 580 CCA, 900 MCA which seems a bit small for the D4 260

 

[koedding@comcast.net]

All,
Thank you for your quick replies and sage advice. You've confirmed what I had thought. Like anything else, it's better to get a few second opinions, before making a significant investment. Besides, this is more or less a DIY project, that this retired Army maintenance guy, should be able to handle. I do regular "PMCS", which is critical. But I leave my annual diesel service (Volvo D3) to my former USMC wrench turner. He is very detail oriented.

 

[scross]

Mikey,
The C-28 uses Group 31 sized (13×6.8×9.4 in) batteries. They are only slightly larger in physical dimensions than the smaller Group 27 (12×6.8×8.9 in) batteries. The mail difference is the 1” longer length.
Your 580 CCA seems really low for an engine starting battery. For the VP D4-260, VP recommend the engine battery have 1150 CCA. A lower CCA will probably work but I wanted to go with what VP recommended for my engine.
The X2Power has the same specs and a better 4 year replacement warranty than the similar NorthStar and Odyssey batteries. They are all made at the same plant.

PS: VP recommends a minimum of 760 CCA for the D3-220 in SOLAS operations.
https://pubs.volvopenta.com/publications/47709538

Mikey: I had replaced the two house batteries last month per my post above. Thruster battery replacement is next on my list.