Cranking Battery for a Volvo MD11c. Advice please.

[FairweatherDave]

The tech. data for the engine states max battery capacity 150Ah,starter motor rating 1.5kW or (2Ah) and an alternator rating(W) of 35. There is no mention of the Cold Cranking requirements in the manual. The battery that has a dead cell was a Squadron Sealed For Life 100 Ah Dual purpose (ie deep cycle marine/recreation battery). My house battery is a wet leisure battery 85 Ah. Charging is off the 1 2 both switch and a single alternator.
My sailing is fortnightly for day sails and the occasional weekend off a swinging mooring for the summer (?!) season. Old boat, no intention of spending much on new stuff, and power consumption on the boat generally minimal. (Basic camping). But I do require her to start. My brain is fried with the many posts here and Nigel Calder. What should I chose? Easily I could get another 85 Ah leisure battery (no worries about battery type and size) but this stuff about cranking power?......
Thanks for any replies.

 

[sailorman]

The tech. data for the engine states max battery capacity 150Ah,starter motor rating 1.5kW or (2Ah) and an alternator rating(W) of 35. There is no mention of the Cold Cranking requirements in the manual. The battery that has a dead cell was a Squadron Sealed For Life 100 Ah Dual purpose (ie deep cycle marine/recreation battery). My house battery is a wet leisure battery 85 Ah. Charging is off the 1 2 both switch and a single alternator.
My sailing is fortnightly for day sails and the occasional weekend off a swinging mooring for the summer (?!) season. Old boat, no intention of spending much on new stuff, and power consumption on the boat generally minimal. (Basic camping). But I do require her to start. My brain is fried with the many posts here and Nigel Calder. What should I chose? Easily I could get another 85 Ah leisure battery (no worries about battery type and size) but this stuff about cranking power?......
Thanks for any replies.

any one of these to fit your battery box
http://www.batterymegastore.co.uk/products/group/?c=Battery&a=Boat

http://www.alpha-batteries.co.uk/125-ah-xplorerleisure-battery/

 

[Tranona]

Any battery for a small diesel engine car will do if you use it solely for engine start and recharge it immediately after using. An automatic split charge with a VSR is good but controlled use of 1/2 switch will do. Alternatively use your leisure battery and get a bigger capacity house battery.

 

[VicS]

The tech. data for the engine states max battery capacity 150Ah,starter motor rating 1.5kW or (2Ah) and an alternator rating(W) of 35. There is no mention of the Cold Cranking requirements in the manual. The battery that has a dead cell was a Squadron Sealed For Life 100 Ah Dual purpose (ie deep cycle marine/recreation battery). My house battery is a wet leisure battery 85 Ah. Charging is off the 1 2 both switch and a single alternator.
My sailing is fortnightly for day sails and the occasional weekend off a swinging mooring for the summer (?!) season. Old boat, no intention of spending much on new stuff, and power consumption on the boat generally minimal. (Basic camping). But I do require her to start. My brain is fried with the many posts here and Nigel Calder. What should I chose? Easily I could get another 85 Ah leisure battery (no worries about battery type and size) but this stuff about cranking power?......
Thanks for any replies.

They have revised the size recommendation... the manual I have downloaded says max 70Ah.
Looks as though they have changed the starter motor spec as well ( used to be 1.1kW) .. not increased the alternator rating though!

Any automotive starter battery in the range will have an adequate CCA . If you have the 1.5 kW starter motor opt for something a larger than the old 70Ah recommendation I would suggest.
Some reservations about using a leisure battery for starting. Some quote CCA implying Ok for occasional starting use . Some do not quote a CCA. For that reason Id go with the leisure battery for domestics and occasional starting but opt for a pure starter battery for normal starting duties.

No body has been able to explain why Volvo quote max Ah ratings!

 

[FairweatherDave]

Thanks for the replies. Each is useful, but stll some questions....

Any battery for a small diesel engine car will do if you use it solely for engine start and recharge it immediately after using. An automatic split charge with a VSR is good but controlled use of 1/2 switch will do. Alternatively use your leisure battery and get a bigger capacity house battery.

This is where I get a bit stuck, (apologies if it is a bit basic) Using the 1/2 switch and engine running I know you prioritise the cranking battery first by setting it on both or just the cranking battery. But when do you switch over to just the house battery setting? Is that ONLY for when you have the engine off for sailing or at anchor? (ie consuming batterypower but not generating). Assuming I don't have the automatic split charge with VSR how should I know when to stop charging the cranking battery? (I do know never to switch to OFF while the engine is running )

Secondly should I be worried about the two different types of battery charging at the same time, probably slightly different capacities? If I got another Sealed For Life Deep cycling wet battery such as that recommended by sailorman can I charge it on the BOTH setting alongside my Leisure Deep cycling wet battery (they are both "wet") or do I just use the Battery 1 and then Battery 2 options on the switch. (Is that what you are implying by "controlled use" Tranona?) Sorry if it comes accross I am being pedantic but I understand the theory to a point and want to maximise my battery life etc without upgrading the charging system (other priorities).

I guess another way of posing the question is how should a pure starter battery co-exist with a leisure battery using the 1/2/both switch?

 

[Tranona]

A start battery needs very little charging particularly if the engine starts easily. Personally I would ditch the current switch and fit a BEP Marine switch cluster which has a VSR to split the charge, separate isolation switches for each bank and a parallel switch to use the house battery for starting. Not a lot of money (relatively) and easy to fit.

 

[sailorman]

Thanks for the replies. Each is useful, but stll some questions....


This is where I get a bit stuck, (apologies if it is a bit basic) Using the 1/2 switch and engine running I know you prioritise the cranking battery first by setting it on both or just the cranking battery. But when do you switch over to just the house battery setting? Is that ONLY for when you have the engine off for sailing or at anchor? (ie consuming batterypower but not generating). Assuming I don't have the automatic split charge with VSR how should I know when to stop charging the cranking battery? (I do know never to switch to OFF while the engine is running )

Secondly should I be worried about the two different types of battery charging at the same time, probably slightly different capacities? If I got another Sealed For Life Deep cycling wet battery such as that recommended by sailorman can I charge it on the BOTH setting alongside my Leisure Deep cycling wet battery (they are both "wet") or do I just use the Battery 1 and then Battery 2 options on the switch. (Is that what you are implying by "controlled use" Tranona?) Sorry if it comes accross I am being pedantic but I understand the theory to a point and want to maximise my battery life etc without upgrading the charging system (other priorities).

I guess another way of posing the question is how should a pure starter battery co-exist with a leisure battery using the 1/2/both switch?

i have 2 battery banks, all are the same battery
1 x 115 Ah engine
3 x 115 Ah domestic (345Ah total)

in your case i would swap their uses now & again, so that they all get some use rather than an a dedicated engine battery, that is only there for occasional use.
as for the differing batteries, a wet cell is a wet cell no matter what its called on a label. all are the same except in thickness of the cell plates to better cope with the expected type of use

 

[VicS]

Thanks for the replies. Each is useful, but stll some questions....


This is where I get a bit stuck, (apologies if it is a bit basic) Using the 1/2 switch and engine running I know you prioritise the cranking battery first by setting it on both or just the cranking battery. But when do you switch over to just the house battery setting? Is that ONLY for when you have the engine off for sailing or at anchor? (ie consuming batterypower but not generating). Assuming I don't have the automatic split charge with VSR how should I know when to stop charging the cranking battery? (I do know never to switch to OFF while the engine is running )

Secondly should I be worried about the two different types of battery charging at the same time, probably slightly different capacities? If I got another Sealed For Life Deep cycling wet battery such as that recommended by sailorman can I charge it on the BOTH setting alongside my Leisure Deep cycling wet battery (they are both "wet") or do I just use the Battery 1 and then Battery 2 options on the switch. (Is that what you are implying by "controlled use" Tranona?) Sorry if it comes accross I am being pedantic but I understand the theory to a point and want to maximise my battery life etc without upgrading the charging system (other priorities).

I guess another way of posing the question is how should a pure starter battery co-exist with a leisure battery using the 1/2/both switch?

A leisure battery is similar to a starter battery... but has different thickness plates I beleive .. so the two should happily co-exist .

What what the person I sailed with did and what I would do is.

1. Select the starter battery
2. Start the engine
3. Alllow the engine to re-charge the starter battery...... useful if you have a voltmeter and/ or ammeter to judge when its charged
4. Switch via "both" to the house battery..... keep the engine running until that is also charged.
5. Keep the house battery selected until you switch off all the electrics or want to start the engine again.

You could keep the batteries paralleled in 4 above while the engine is running if you wish

When the engine is not running you can change batteries via the "off" position ( in fact we normally did that) but you must not switch to "off" while it is running or you risk damaging the alternator diodes

 

[KellysEye]

We had a 100 CCA (Cold Cranking Amps) battery for a MD17C. House batteries are completely different to an engine start battery and should be deep-cycle golf cart batteries, Trojan T108 is an example.

 

[VicS]

We had a 100 CCA (Cold Cranking Amps) battery for a MD17C. House batteries are completely different to an engine start battery and should be deep-cycle golf cart batteries, Trojan T108 is an example.

You dont mean 100CCA do you ?? That's very small as starter batteries go.

 

[FairweatherDave]

Once again thanks all. Tranona your proposal would be my next step and I am sure I could do the electrics if I put my mind to it, but just not yet. My sailing and electric demands are not there yet. VicS thanks for your description, that confirms what I did last season (or what I usually did ). So it is back to battery choice. My house battery was new at the start of last season and is a Diamond Leisure XEL85 battery (semi traction/suitable for caravanning and marine leisure use etc etc). I am tempted to go sailorman's way and match it with a second Diamond Leisure XEL85 and treat the same, ie rotating which one is preserved as the cranking battery. It sounds from the initial responses that it is likely to have the adequate CCA. It does have printed on it in small writing (LM 26 - 50 @20HR/1) not sure what that means.

 

[pvb]

We had a 100 CCA (Cold Cranking Amps) battery for a MD17C. House batteries are completely different to an engine start battery and should be deep-cycle golf cart batteries, Trojan T108 is an example.

As VicS has said, 100CCA is tiny - my mower battery has more power than that! Also, I think you'll find that there's no such thing as a Trojan T108.

 

[sailorman]

Once again thanks all. Tranona your proposal would be my next step and I am sure I could do the electrics if I put my mind to it, but just not yet. My sailing and electric demands are not there yet. VicS thanks for your description, that confirms what I did last season (or what I usually did ). So it is back to battery choice. My house battery was new at the start of last season and is a Diamond Leisure XEL85 battery (semi traction/suitable for caravanning and marine leisure use etc etc). I am tempted to go sailorman's way and match it with a second Diamond Leisure XEL85 and treat the same, ie rotating which one is preserved as the cranking battery. It sounds from the initial responses that it is likely to have the adequate CCA. It does have printed on it in small writing (LM 26 - 50 @20HR/1) not sure what that means.

http://www.alpha-batteries.co.uk/125-ah-xplorerleisure-battery/
Product Description


Xplorer- The new range of leisure batteries. This battery is part of the new range of Xplorer leisure batteries designed for long life and deep discharging. Safe, Clean and portable this battery is fully sealed for life and comes with a massive FOUR year warranty. Unlike standard leisure batteries which may do between 100-150 recharge cycles the new Xplorer range will do 500! yes 500! with a massive 4 year warranty
Product Specification
Brand: Xplorer
Voltage: 12V
Capacity (Ah): 125
Usage Rating: High
CCA / EN: 900
CCA / SAE: 1000
Terminal Type: Dual Terminals (Both)
Terminal Layout: Positive on Left (Layout 1)
Height (mm): 242
Width (mm): 175
Length (mm): 330
Construction: Lead Acid
Maintenance Free: Yes
Warranty (Years): 4
Recommended Golf Holes: No
T-BAR Connection Supplied: No
Deep Cycle: Yes
Calcium Technology: Yes
Recharge Cycles: 500
Sealed: Yes
Hard Rubber Construction: No
Made in the UK: No


or from batterymega store
http://www.batterymegastore.co.uk/product/DC31/

 

[FairweatherDave]

as for the differing batteries, a wet cell is a wet cell no matter what its called on a label. all are the same except in thickness of the cell plates to better cope with the expected type of use

Okay. I shall match my Diamond Leisure with one of the Alpha's. Many thanks.

 

[KellysEye]

>100CCA

Yes we did have that for a 35 HP engine and also for a 4KVa generator, they both worked fine.

> there's no such thing as a Trojan T108.

Sorry I meant T105

 

[FairweatherDave]

should I be worried about the two different types of battery charging at the same time, probably slightly different capacities? If I got another Sealed For Life Deep cycling wet battery such as that recommended by sailorman can I charge it on the BOTH setting alongside my Leisure Deep cycling wet battery (they are both "wet") or do I just use the Battery 1 and then Battery 2 options on the switch. (Is that what you are implying by "controlled use" Tranona?) Sorry if it comes accross I am being pedantic but I understand the theory to a point and want to maximise my battery life etc without upgrading the charging system (other priorities).

I guess another way of posing the question is how should a pure starter battery co-exist with a leisure battery using the 1/2/both switch?

Final double check..... I have ordered the new battery, and gone with the bigger capacity but similar type. Re-reading the advice seems to be there is not much difference between charging on the "Both" setting and "fully" charging on Battery 1 and then going direct to Battery 2 to avoid simultaneously charging two different capacity batteries.