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Cummins diesel batteries

Posted: September 17th, 2019, 9:29 am
by rgaidies
My batteries are done.
I disconnected each battery, load tested and all registered as bad.
I am now looking at replacing all 4 batteries but want to make an educated choice.
Reading many articles on battery selection has only left me more confused.
My choice is now down to a MotoMaster Nautilus Ultra Group 31 AGM Deep Cycle Battery
1000 marine crank amps, 105 amp hours, 200 minutes reserve capacity
The price range of batteries leads me to believe that higher price may be better quality but I am skeptical after my research.
Any feedback would be appreciated.

Re: Cummins diesel batteries

Posted: September 17th, 2019, 5:19 pm
by Viper
A couple of things;
- first make sure your current battery charger is designed or has the option to charge AGM batteries.
- don't know what size engines you have but the above batteries are only 800 CCA, you may want to consider something beefier like 1000 CCA
- AGMs are less prone to voltage drops and can handle starting and discharges better than flooded types but you may want to consider Start batteries for the engines and Deep Cycle batteries for house loads

Personally I'm not a fan of that brand but they're definitely a good price point!

Re: Cummins diesel batteries

Posted: September 17th, 2019, 5:35 pm
by bud37
rgaidies wrote:Source of the post My batteries are done.
I disconnected each battery, load tested and all registered as bad.
I am now looking at replacing all 4 batteries but want to make an educated choice.
Reading many articles on battery selection has only left me more confused.
My choice is now down to a MotoMaster Nautilus Ultra Group 31 AGM Deep Cycle Battery
1000 marine crank amps, 105 amp hours, 200 minutes reserve capacity
The price range of batteries leads me to believe that higher price may be better quality but I am skeptical after my research.
Any feedback would be appreciated.


I agree with Viper......for the diesels you want start batteries only.....then you can use deep cycle for the house loads.........check out Total battery in Barrie, they have a few different lines and could maybe help with your choice..

Re: Cummins diesel batteries

Posted: September 17th, 2019, 6:21 pm
by Viper
+1 on Total Battery in Barrie.

Don't get stuck on the AGM type, they're great batteries but I'd rather spend my budget on a really good set of flooded batteries than spend the same budget on a cheap set of AGMs, there's a difference.

Re: Cummins diesel batteries

Posted: September 17th, 2019, 7:10 pm
by Midnightsun
I have gone the AGM route however have gone back to typical wet cell or your standard battery if you prefer. AGM is way over estimated IMHO.
Walmart has group 31 batteries, installed 4 of these to handle thrusters and starting, could not be happier. House bank consists of dual Trojan L16’s for total of 435 ah.
https://www.walmart.ca/en/ip/everstart- ... 0195362471

Re: Cummins diesel batteries

Posted: September 17th, 2019, 7:24 pm
by Viper
Hans, are you using that very battery at 800 MCA for your D6s?

Re: Cummins diesel batteries

Posted: September 17th, 2019, 9:58 pm
by buster53
No question that AGM's are very good batteries, but I still believe that flooded is the best bang for your buck

Re: Cummins diesel batteries

Posted: September 18th, 2019, 5:52 am
by rgaidies
Below are the details on the battery
specs claim 1370 marine crank amps
With a 48 month free replacement I'm thinking these are adequate.
My vessel only has 4 batteries "not" including the generator start battery.
At some point I may isolate house from starter but as I just purchased the vessel i'm not inclined to do that just yet.
With the diesel generator my type of boating should provide me all the power I need.
However good points and advice, especially charger capability for AGM batteries, as I hadn't considered that.
Much thanks to those that offered their input.


MotoMaster Nautilus Ultra XD Group 31 High Performance AGM Deep Cycle Battery's 99.99% pure lead AGM (absorbed glass mat) technology and precision robotic assembly to deliver extreme power, endurance and reliability
Capable of over 400 charge/discharge cycles to 80% depth of discharge and over 900 cycles at 50% depth of discharge - that's more than 2x the cycle life of regular AGM batteries and 4X the cycle life of conventional flooded deep cycle batteries
More Useable Power: Unlike conventional flooded batteries that should never be taken beyond 50% depth of discharge, pure lead AGM technology can withstand deep discharges allowing you to take advantage of more of the battery's rated amp hour
Rapid Recharging: Accepts the maximum amount of amps that an alternator or battery charger can deliver for astonishingly fast recharges
Clean, Safe and Truly Maintenance-free: No messy or dangerous acid spills, can be mounted in virtually any position, no gassing (under normal charging), never requires water to be added and brass terminals that will never build corrosion
Extremely Low Self-Discharge: Stores for up to 2 years on a full charge with no loss of capacity, ideal for off-season storage
Extreme Vibration Resistance: Up to 28X more vibration resistant than a conventional marine battery to handle the roughest waters or terrain
Longest Life: Up to 2x longer service life than regular AGM batteries and 6x longer than conventional flooded batteries
Group size: 31
Pulse crank amps, 1370 marine crank amps, 103 amp hours, 220 minute reserve capacity
Dimensions: 13" L x 6-3/4" W x 9-3/4" H (33 x 17 x 63.5 )

Re: Cummins diesel batteries

Posted: September 18th, 2019, 7:06 am
by Midnightsun
Viper wrote:Source of the post Hans, are you using that very battery at 800 MCA for your D6s?


Yep.

Re: Cummins diesel batteries

Posted: September 21st, 2019, 1:10 pm
by Viper
Probably not that bad since you're running four of them but I'm pretty sure the recommended minimum per VP for a D6 is 2 x 800 CCA. I think the single battery recommendation is around 1100-1200 CCA. 800 MCA will only be about 640 CCA. You're probably fine with 4 of them otherwise one might be taxing the batteries and/or starters, and have the ECU and related systems experience brownouts/voltage drops during startup....FWIW