Battery Changeout

JJGKJG

Member
Joined
Mar 15, 2024
Messages
10
Fluid Motion Model
C-28
What is the recommended replacement batteries for a 2018 C28 with 1-start, 1-thruster and 2-house batteries currently. They all appear to be the Universal Battery UB121100K. No generator. Right now the start battery cranks slow with full charge and all connections are good. Not sure what the cca rating is for the UB121100 but I question its use as a starting battery. I am looking at the Victron line and in particular the super cycle for house batteries. Not sure if they can be used for start and thruster. All current batteries are original. Any input would be appreciated. Thx
 
The CCA of the universals is not the best. When new, they do fine. At 3 years old, on cold mornings after a night at anchor, they can struggle. Nothing an hour of solar (340w) can't solve or bridging to house.

I have replaced mine 3 times in my boat. I evaluate the options every time and I come back to replacing with like for like universals.
I replace them when, on cold mornings, the engine battery doesn't start the engine consistently. This is a good sign that the house is getting old, too.
With my solar setup I don't use much power at all from the batteries and we are low power users on the boat.

some of my thinking.

1. I want to keep the same charging profile across all batteries. So mixing battery make is not an option.
2. Lithium is cost-prohibitive to install at this point and I don't need the functionality
3. the price point of the universals is great and I actually think they are pretty good AGM's compared to some of the retail batteries available. Not many offer 110aH like these.
4. Delivery cost is a major factor with such heavy items. I have purchased the universals from Home Depot and Amazon both with free delivery. This is a great feature. my delivery guy wasn't that happy having hauled them up the porch steps 🙂
5. I'm going to replace them in 3-4 years anyway. The price point is a factor when buying 4 batteries.

There will be people who say well, if the price is the top factor, go with golf cart or other non-AGM batteries. But for me, AGM fits the sweet spot.

Lots of folks like the optima engine start battery for its CCA. but then I have to change all of them to keep the battery charging profile the same. that's like 2X the price point. I can just replace my batteries sooner!
Others have tried firefly but quality and value doesn't seem to be there. Other folks have used lifeline. again expensive compared with the universals.

for reference
universal at Homedepot = $218 delivered
X2 at batteries plus = $576

https://www.homedepot.com/p/UPG-12-Volt ... /203770534
https://www.batteriesplus.com/productde ... li31agmdpm
 
VP recommends a minimum of 950 CCA for starter batteries in Safety of Life at Sea (SOLAS) boats using their D4 series engines. The highest CCA rated battery I could find was the 1150 CCA rated Odyssey Extreme 31M AGM and the X2Power 31M AGM from Batteries Plus with identical specs to the Odyssey. Went with the X2Power (at BatteriesPlus’s frequent 15% off sale) for both starter and thruster batteries. Excellent warranty on both the Odyssey and X2Power. Haven’t had any issues in the first season of use.
For the house batteries, I like the 125 Amp/Hr VE Super Cycle AGMs but at $350+ each they are a bit pricey.
 
PS: I bought the X2Power 31T AGM which lists for $433 vs the 31M which is $66 more. Only difference between the M and T versions is the battery terminals. The single terminal on the 31T worked fine for me. At the frequent sale price of 15% off the price for the 31T would be $368 each.
I like the X2Power non-prorated 48 month replacement warranty too.
 
Those of you that have swapped to the x2 and similar higher cranking amp batteries but left the house batteries the dual purpose type have you noticed any problems with the different charging profiles? I am going to be upgrading my starting battery soon Iv already had the dual purpose battery struggle this summer and want to swap it out before fall hits and I’m trying to cranks it when it’s 10 degrees out.
 
I’m no battery expert, my 2021 r29 came with true starting batteries for the engine and thrusters and universal for the house so I figured (perhaps incorrectly) that the charging profile wasn’t a big deal when I replaced them.
 
For battery charging what matters most is the basic battery type. (AGM, vs Flooded…Lithium is another animal!). While the details may vary slightly, as long as all the batteries are the same basic type (E.g. AGM, or Flooded) using the same charging profile should be generally acceptable. Whether they are starting batts, or deep discharge, as long as they are all AGM’s, using the same charging profile should be fine. For AGMs, for the most part, Deep Discharge (house) vs. Starting (engine) are the same chemistry but have more or less lead and can use the same charging profile. Never put Lithium and Lead Acid (AGM, Flooded, or Gel) batteries on the same charging profile.
 
For battery charging what matters most is the basic battery type. (AGM, vs Flooded…Lithium is another animal!). While the details may vary slightly, as long as all the batteries are the same basic type (E.g. AGM, or Flooded) using the same charging profile should be generally acceptable. Whether they are starting batts, or deep discharge, as long as they are all AGM’s, using the same charging profile should be fine. For AGMs, for the most part, Deep Discharge (house) vs. Starting (engine) are the same chemistry but have more or less lead and can use the same charging profile. Never put Lithium and Lead Acid (AGM, Flooded, or Gel) batteries on the same charging profile.
This was my understanding. Might as well run the correct type of AGM for at least the starting and possibly the thruster battery too.
 
This was my understanding. Might as well run the correct type of AGM for at least the starting and possibly the thruster battery too.
I think you can get away with some variance. The insights I gathered were from the solar battery field talking about getting batteries to their full SOC. In that if you don’t charge the batteries with the right profile you can leave a lot of the capacity unused. Seeing as we only have 100ah of capacity I wanted to have as much available and give my batteries the best chance of lasting a long time.
 
Okay, I have changed my mind on this topic. After installing another brand new set of universals, at anchor in the morning, I get a slow crank, and the engine battery voltage drops to about 11v, which then slowly recovers—as if the batteries are discharged (they are not - they were sitting at 12.85v ).

after a little research about battery surface charging and surface discharge, I suspect whats going in the universal AGM design (and why they have low CCA) is they just don't have a design that allows for sufficient amps to be pulled off the battery quickly in volume at the point of cranking. Such a high amp cranking moment can only use surface charge to quickly provide power and the universal design with its low CCA isn't up to the task. These are classic house batteries only, with reasonable battery storage but not high CCA.
I'm sorry if my posts on this matter suggested people should replace their engine battery with new Universals.
I installed an X2 1150CCA AGM today. Next week, I will test it at anchor and report back.

 
Okay, I have changed my mind on this topic. After installing another brand new set of universals, at anchor in the morning, I get a slow crank, and the engine battery voltage drops to about 11v, which then slowly recovers—as if the batteries are discharged (they are not - they were sitting at 12.85v ).

after a little research about battery surface charging and surface discharge, I suspect whats going in the universal AGM design (and why they have low CCA) is they just don't have a design that allows for sufficient amps to be pulled off the battery quickly in volume at the point of cranking. Such a high amp cranking moment can only use surface charge to quickly provide power and the universal design with its low CCA isn't up to the task. These are classic house batteries only, with reasonable battery storage but not high CCA.
I'm sorry if my posts on this matter suggested people should replace their engine battery with new Universals.
I installed an X2 1150CCA AGM today. Next week, I will test it at anchor and report back.

Good update. This goes in line with my thinking I’m going to pick up the same x2 probably this week. I launched my boat last Wednesday and the engine battery didn’t want to start the boat this was after 3 week of sitting on the charger while I was away at work. The dual purpose batteries just don’t have the CCA/MCA that is needed for a diesel I’d imagine it would be easier to get away with this on a gas outboard.
 
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