starting battery

[tugbruno]

Just bought a Nordic Tug 32 and need to replace the 4D starting battery. Has a 220 hp Cummins 6BT. Any suggestions

Tug Bruno

 

[Airstream345]

Welcome! Are you considering alternatives to the 4D or looking for feedback on 4D brands?

 

[DavidM]

A good Group 31 has close to 1,000 CCA and will start the Cummins just fine. About half the weight of a 4D. If you use a 4D you will have to lift that beast out one day. Do it once and get rid of your 4D.

David

 

[tugbruno]

Welcome! Are you considering alternatives to the 4D or looking for feedback on 4D brands?

Looking at all my options. Would like to go with a group 31 AGM, but not sure if my charger can charge 2 different battery types since my house batteries are flooded. The size and weight of the 4D make it difficult to access.

 

[RCook]

I don't think I'd worry about charging a starting AGM with flooded battery voltage settings. I and friends have used AGM's in trucks for many years with great results. Lots of folks use them with outboards. Seems to me exactly perfect AGM charging voltages are more of an issue with house banks.

 

[aboatman]

The charging settings for AGM and flooded cell are close enough that it won't matter.

A single group 31 AGM will probably start your engine just fine but if it doesn't, you can wire two in parallel for twice the starting power.

 

[Larry M]

The charging settings for AGM and flooded cell are close enough that it won't matter....

Yup. We’ve been using Optima batteries for our start bank and Trojan T-105s for the house bank for 20 plus years. We usually switch out the Optimas after 8-10 years because of the age only and don’t want to get stuck. The house bank about every 5 years. You can set your charting parameters to match your house bank, wet cells, and the Optimas will be charged within their recommended settings as per the manufacturer. This is for the Optima Yellow Tops.

Recommended charging information:

Alternator:
13.65 to 15.0 volts, no amperage limit.
Battery Charger:
13.8 to 15.0 volts, 10 amps maximum, approximately for six to twelve hours.
Cyclic Applications:
14.7 volts, no current limit as long as battery temperature remains below 125°F (51.7°C). When current falls below one amp, finish with two-amp constant current for one hour.
Rapid Recharge:
Maximum voltage 15.6 volts (regulated), no current limit as long as battery temperature remains below 125°F (51.7°C). Charge until current drops below one amp.
Float Charge:
13.2 to 13.8 volts, one amp maximum current, time indefinite (at lower voltage)

https://www.optimabatteries.com/en-us/support/charging/charging-tips