volvo D4 320 start battery requirements

[sailor1man]

what is CCA requirement for D4 320 start battery as recommended by Volvo? (Volvo manual does not have, volvo dealer says call FM, search of tugnugs has some generic info, volvo penta website only has manuals).
In addition, what are FM recommendations for house battery bank and thruster battery in terms of C20 amp hours; my 2020 R31 CB boat had new batteries added.

 

[glider4]

I searched for this as well last summer for my D4-260. The only VP documents I found were for D4s put in service on fast rescue boats (SOLAS rated) where the engine needs to start every time.
https://www.dieselservicesofamerica.com ... -SOLAS.pdf
On that document they say the starting battery for a D4 should have 1150 CCAs. The only AGM batteries I know of that have that in a Group 31 size were the X2Power from BatteriesPlus and the Odyssey ODX-AGM31M Extreme Marine Battery. I think these two batteries are the same just different branding. I went with the X2Power for my D4-260 for both engine and thruster.

PS: The Universal Power UB121100 deep cycle battery used by FM has only a 535 CCA rating according to this website so anything better than 535 CCAs would be an improvement.
https://www.1000bulbs.com/product/56373 ... 00FL1.html
I understand a number of folks with D4s have used the Optima BCI Group 31M 75AH 900CCA AGM Deep Cycle Marine & RV Battery with good results.

 

[sailor1man]

Finally got my local boatyard mechanic to penetrate through to Volvo Penta to get official recommendations:
down to 41F, min is 750 CCA and 75 Ah
down to 23F, min is 800 CCA and 75 Ah