What Size Starter Battery for D1-20

Spirit (of Glenans)

Spirit (of Glenans)

Well-Known Member
Joined
28 Mar 2017
Messages
3,341
Location
Me; Nth County Dublin, Boat;Malahide
Visit site
My boat came with a 105Ah servoce battery and an 85Ah starter battery for the VP D1-20, both housed in a moulded compartment under the berth in the aft cabin. Charging is controlled by some type of splitter with cooling fins.
My idea is to convert to a bank of two 105Ah service batteries in that compartment and fit a less bulky starter battery in the smaller neighbouring compartment. I would like to know what is the optimum battery, in terms of amp-hours and cranking capacity, that I can use with my engine. I' m hoping that I can get one that will fit in the smaller, triangular space without my having to do any GRP alterations. I would prefer to stick with lead-acid so as not to have the complication of different charging regimes.
 
Last edited:
For what it's worth, our D1-30 starts from a 28Ah AGM. The branding on the battery has pictures of snowmobiles ?

Pete
 
Spirit (of Glenans) said:
I would like to know what is the optimum battery, in terms of amp-hours and cranking capacity, that I can use with my engine. I' m hoping that I can get one that will fit in the smaller, triangular space without my having to do any GRP alterations. I would prefer to stick with lead-acid so as not to have the complication of different charging regimes.
Click to expand...

Not a VP, but for an engine of similar size, a 20hp Beta, the manufacturer suggests a starter battery capacity of 450 CCA minimum.
Ah-rating is IMO mostly a question of how many cranking attempts you will have if you run in to stating difficulties, for instance because of fuel problems.
In my installation I put an AGM starter battery (Red Flash 1100, about 40 Ah) laying on its side in a space that would not have housed a normal sized wet battery. Thereby I was able to increase the house bank from 2 to 3 batteries. For nine years these where standard wet leisure batteries, different charging regimes has not been an issue.
 
Last edited:
If you can afford it a Red Flash 1100 is the way to go, although you can use the smaller 1000 which is a bit smaller physically (but not much cheaper). I Have a 750 (even smaller capacity!) in my Morgan which is the original from 2003 and starts the 1800cc engine with no problems. Apart from long life and small dimensions they can also be mounted in any orientation.

If you don't want to spend that amount of money then a car battery of around 45-50AH capacity such as fitted to small diesel cars will also do. Exact choice will depend on size and shape.
 
Spirit (of Glenans) said:
My boat came with a 105Ah servoce battery and an 85Ah starter battery for the VP D1-20, both housed in a moulded compartment under the berth in the aft cabin. Charging is controlled by some type of splitter with cooling fins.
My idea is to convert to a bank of two 105Ah service batteries in that compartment and fit a less bulky starter battery in the smaller neighbouring compartment. I would like to know what is the optimum battery, in terms of amp-hours and cranking capacity, that I can use with my engine. I' m hoping that I can get one that will fit in the smaller, triangular space without my having to do any GRP alterations. I would prefer to stick with lead-acid so as not to have the complication of different charging regimes.
Click to expand...

The owners manual suggests / specifies a 70Ah battery , but does not mention a CCA rating however a 70 Ah starter battery is likely to have a CCA rating somewhere in the range of 550 to 750 amps

IF you decide to go down the Red Flash route be aware that the CCA ratings quoted by most, if not all, suppliers are in fact the max discharge current. The actual CCA figures can be found on DMS technologies website at http://dmstech.co.uk/downloads/DMS_data_redflash_highrate_web.pdf.

Compare that with the figures for max discharge here: Red Flash High Rate | DMS technologies

Forumites have fallen foul of this discrepancy in the past.
 
The Volvo D1-20 is a tiny engine, only about 750cc, so it doesn't need an enormous battery. Volvo Penta have always adopted a strange policy of quoting Ah capacity for starter batteries, rather than a CCA figure. The D1-20 has about a 2kW starter motor, so assume it'll need 200A or so to start it. Any small car battery should be OK for that - look at 054 or 055 batteries which will be about 35Ah-40Ah and will have a CCA of around 300A. They also typically cost about £40. Spending getting on for £200 on a Red Flash battery seems pointless.
 
pvb said:
Volvo Penta have always adopted a strange policy of quoting Ah capacity for starter batteries, rather than a CCA figure.
Click to expand...
For the 2003, at least it makes a kind of sense. You need a fair few AH to keep it churning long enough to start on a cold day :rolleyes:

I think PVB has it right. No need for a fancy expensive battery. I used a second hand battery out of an ambulance for years on my 2003
 
pvb said:
Spending getting on for £200 on a Red Flash battery seems pointless.
Click to expand...
If a slim AGM battery laying on its side is the only option to make use of the available space, then the exercise is not pointless, only more expensive.
 
Last edited:
Moodys S31s came as standard with one 105 amp in a box big enough for two, an option was a second 105 dedicated to starting, massive overkill.
Engine is a D1-20, now with a pair of 105 amp domestics which fill the original battery space under the bunk in the aft cabin just behind the engine, a more recently added starter battery also drives the windlass, it is an 85 amp Numax selected mainly because it is compact, I had it lying in my garage, it had screw on terminals which suited my crimp terminals, in the handiest position and it fitted comfortably in a well secured box I made next to the original battery box. The two banks are fused separately. Not sold as a dedicated starter battery but more than enough power for starting and lifting the anchor and impressively long life. The Moody circuit has the additional benefit of a switch which allows the domestics to be used for starting but with the D1-20 so far it fires with one touch.
 
Quandary said:
Moodys S31s came as standard with one 105 amp in a box big enough for two, an option was a second 105 dedicated to starting, massive overkill.
Engine is a D1-20, now with a pair of 105 amp domestics which fill the original battery space under the bunk in the aft cabin just behind the engine, a more recently added starter battery also drives the windlass, it is an 85 amp Numax selected mainly because it is compact, I had it lying in my garage, it had screw on terminals which suited my crimp terminals, in the handiest position and it fitted comfortably in a well secured box I made next to the original battery box. The two banks are fused separately. Not sold as a dedicated starter battery but more than enough power for starting and lifting the anchor and impressively long life. The Moody circuit has the additional benefit of a switch which allows the domestics to be used for starting but with the D1-20 so far it fires with one touch.
Click to expand...
Spirit (of Glenans) said:
My boat came with a 105Ah servoce battery and an 85Ah starter battery for the VP D1-20, both housed in a moulded compartment under the berth in the aft cabin. Charging is controlled by some type of splitter with cooling fins.
My idea is to convert to a bank of two 105Ah service batteries in that compartment and fit a less bulky starter battery in the smaller neighbouring compartment. I would like to know what is the optimum battery, in terms of amp-hours and cranking capacity, that I can use with my engine. I' m hoping that I can get one that will fit in the smaller, triangular space without my having to do any GRP alterations. I would prefer to stick with lead-acid so as not to have the complication of different charging regimes.
Click to expand...
The replies so far have reinforced my opinion that I can actually get by with a smaller starting battery, enabling me to double the size of my service bank. I will be visiting the boat shortly and will measure the triangular space so that I can research what size battery will fit in - square, squat rectangular or long and narrow. It will be a first step in the direction of " Operation Upgrade".
Thanks all for your contributions.
 
I have a red flash circa 35 amp for a starter battery due to space limitations. Then I have 2 No 100 amp AGM house batteries. If I have a problem with power from the starter battery I have a switch installed to link all 3 batteries in emergency. Even if they are a bit low the house batteries will give quite a bit more oomph when hooked in tandem
 
You must log in or register to reply here.

Share this page

Top