Smallest possible starter battery for 3GM30?

skyflyer

skyflyer

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I plan to add a dedicated starter battery for my Yanmar 3GM30 but have two opposing issues:-

Firstly my house bank is flooded lead acid so all charging (mains, solar, advanced charger) is set up for that regime.

Secondly I am tight on space for the starter battery unless I get into a lot of expensive cabling and fettling to site it remotely, which tends to imply use of AGM or even LiIon

So can anyone recommend a physically small flooded lead acid with adequate CCA for starting what is after all a fairly small engine, by car standards!
 
I use an optima redtop as my starter battery, alongside my Trojan lead acid house battery, using a lead acid charging regime, with no problems at all for about 4 years. If you take a look at the charging specs for the redtop they are pretty similar to lead acid, so you' don't necessarily have to go down the lead acid route. Only downside is the cost...........
 
I used a Red Flash on a 3GM30 for 3 years before I sold the boat in conjunction, my house batteries were AGM but I don't think you will have a problem with normal lead acid batteries. If I remember correctly it was the smallest one and was physically the smallest I could find.
 
I installed a Red Flash alongside the gearbox of my 3GM30F. I believe the battery I installed is no longer available, a 900 https://www.tayna.co.uk/car-batteries/red-flash/900/, photo below. It was the smallest I could buy, only 13Ah, with CCA above the requirement for my starter motor, 200 A. It was OK at first but within less than a season would only start the engine when warm and after charging.

I replaced it with a Red Flash 1100, which has been perfectly OK. I know someone who has the same battery starting a 4 cylinder Yanmar, in his case the battery lies on its side under the engine.
 
vyv_cox said:
I installed a Red Flash alongside the gearbox of my 3GM30F. I believe the battery I installed is no longer available, a 900 https://www.tayna.co.uk/car-batteries/red-flash/900/, photo below. It was the smallest I could buy, only 13Ah, with CCA above the requirement for my starter motor, 200 A. It was OK at first but within less than a season would only start the engine when warm and after charging.
Click to expand...

It's interesting that Red Flash (or Tayna) seem to have given up on small, low-capacity batteries. 26Ah is the smallest now, and an 1100 is 37Ah - same as a bog-standard 038, though two inches thinner and four times the price. Twice the current, but who needs that on a wee boat engine?

Perhaps, in view of your experience, reliability of the very small batteries has been an issue. Whatever the reason, I'm sorry they're gone as I was planning to fit one when my current engine battery, an 063 pinched from my Herald, gives up.
 
According to manual, a 70ah Group 24 is specified. Manufacturers seem to range CCA of between 600a and 800a depending how brave you are!

Assuming the engine is a reliable starter, the Cold Cranking Amps are what to look for. It is possible to get batteries designed for jump start packs that are small and will put out 600CCA, BUT they are around 25ah, so clearly you will be time restricted.
 
The 3GM30 is less than a litre, so why not look for a small diesel car battery? Surely you can fit one in somewhere, and it'll be conventional lead-acid so won't need special charging settings. It'd only cost about £50, compared with £200 or so for a RedFlash, so even if you have to buy a bit of wire you'd still be quids in.
 
JumbleDuck said:
It's interesting that Red Flash (or Tayna) seem to have given up on small, low-capacity batteries. 26Ah is the smallest now, and an 1100 is 37Ah - same as a bog-standard 038, though two inches thinner and four times the price. Twice the current, but who needs that on a wee boat engine?

Perhaps, in view of your experience, reliability of the very small batteries has been an issue. Whatever the reason, I'm sorry they're gone as I was planning to fit one when my current engine battery, an 063 pinched from my Herald, gives up.
Click to expand...

DMS (Red Flash) still list all sizes from 900 (15ah) upwards. Price is justified by the long life. The 750 (26ah) in my Morgan is still fine after nearly 15 years. Duty cycle is much like a boat engine. Long periods of inactivity interspersed with intensive use. Plug into the trickle charger in the winter, but don't usually bother in the summer.

The 1000 seems a good compromise for a boat.
 
vyv_cox said:
I installed a Red Flash alongside the gearbox of my 3GM30F. I believe the battery I installed is no longer available, a 900 https://www.tayna.co.uk/car-batteries/red-flash/900/, photo below. It was the smallest I could buy, only 13Ah, with CCA above the requirement for my starter motor, 200 A. It was OK at first but within less than a season would only start the engine when warm and after charging.

I replaced it with a Red Flash 1100, which has been perfectly OK. I know someone who has the same battery starting a 4 cylinder Yanmar, in his case the battery lies on its side under the engine.
Click to expand...

DMS still list the 900 but it's CCA is only 156A. It's cranking current at +20 Deg is 190. Be careful with claims made by Tayna and BM they frequently differ from manufacturers figures.
The 1100 is 500A CCA.
 
vyv_cox said:
I installed a Red Flash alongside the gearbox of my 3GM30F. I believe the battery I installed is no longer available, a 900 https://www.tayna.co.uk/car-batteries/red-flash/900/, photo below. It was the smallest I could buy, only 13Ah, with CCA above the requirement for my starter motor, 200 A. It was OK at first but within less than a season would only start the engine when warm and after charging.

I replaced it with a Red Flash 1100, which has been perfectly OK. I know someone who has the same battery starting a 4 cylinder Yanmar, in his case the battery lies on its side under the engine.
Click to expand...

Your trouble may have been that the RedFlash 900 in fact has a CCA of only 156 amps ! See this table from DMS Technologies : .... http://www.dmstech.co.uk/downloads/DMS_data_redflash_highrate_web.pdf

Confusingly in another table, .... http://www.dmstech.co.uk/red-flash/red-flash-high-rate/ , they quote maximum discharge currents, (190amps for a RedFlash 900)

I dont know where Tayna are getting their figure from. I though they were quoting the max current figure but it seems not , at least not for the RedFlash 900.



Your RedFlash 1100 has a CCA of 500amps, and a maximum discharge current of 775 amps . Tayna quote the maximum discahrge current of 775 amps as the CCA !


Moral is beware of the CCA figures battery suppliers quote for Red Flash batteries !


Rats........ beaten by Plevier !
 
So this spec would do the job, (under £50)?

Brand Exide
Range Exide Premium
Voltage 12 Volts
Technology Wet
Capacity (C20) 45 Ah
CCA (EN) 390 A
Length 237 mm
Width 132 mm
Height inc. terms 227 mm
Guarantee 4 Years

My existing batteries have cross section 223 x 223mm so this could be squeezed in one end, or even in between the two. 5 inches width - should be do-able!
 
skyflyer said:
So this spec would do the job, (under £50)?

Brand Exide
Range Exide Premium
Voltage 12 Volts
Technology Wet
Capacity (C20) 45 Ah
CCA (EN) 390 A
Length 237 mm
Width 132 mm
Height inc. terms 227 mm
Guarantee 4 Years

My existing batteries have cross section 223 x 223mm so this could be squeezed in one end, or even in between the two. 5 inches width - should be do-able!
Click to expand...

Reckon that would cope easily with your 3GM30.
 
skyflyer said:
So this spec would do the job, (under £50)?

Brand Exide
Range Exide Premium
Voltage 12 Volts
Technology Wet
Capacity (C20) 45 Ah
CCA (EN) 390 A
Length 237 mm
Width 132 mm
Height inc. terms 227 mm
Guarantee 4 Years

My existing batteries have cross section 223 x 223mm so this could be squeezed in one end, or even in between the two. 5 inches width - should be do-able!
Click to expand...

My VP MD2020D is smaller but I have no problem starting it with this small Varta which has a similar spec to the Exide; now into its 4th season. When considering CCA I took comfort in the fact that the figures are for operation at -18C and I have no intention needing that!

https://www.tayna.co.uk/car-batteri...lkm3nEaO_Ug39HfDzMKdZRa9JEQQ73UEaAgnaEALw_wcB

John
 
I changed the battery in my car a little while back.
The old one would start the car, provided it was fully charged, but I felt I wanted a bit more margin.
I measured the capacity of the old battery, about 10Ah to 10V. On a high current test it managed about 150A for 5 seconds, at about 9V, at about 8 degreesC. Not an ISO or SAE or what have you test, just mucking about with what was to hand.
It was supposedly a 90Ah 600CCA battery. It's a 1900cc diesel.
I think it was nine years old!
The point is, engine manuafacturer's spec's have a lot of margin for the battery being older and so forth.
I reckon my motorbike battery would start a 3GM easily, but it would not last many years.

I would guess that Optimas are less available, because people have gone over to Lithium. Particularly in motorsports.
I have seen a Lithium jump pack, about the size of a VHS cassette, start a 2 litre car easily.
 
Tranona said:
DMS (Red Flash) still list all sizes from 900 (15ah) upwards. Price is justified by the long life. The 750 (26ah) in my Morgan is still fine after nearly 15 years.
Click to expand...

Thanks. I have a friend whose Herald survived on the same battery from when his mother bought it in 1966 until he laid it up for a rebuild (currently still under way ...) in 1986. Of course daily use helps enormously.
 
Despite the technological advances it probably a case of the bigger the better. Starting currents peak very high, I've measured 250A on a 3GM30 without the benefit of a 'scope. Remember you have cold temperatures to contend with at times, possible long intervals between charging plus the consequences of the engine not starting! A small automotive battery of about 300+A will probably do the job.
 
savageseadog said:
Despite the technological advances it probably a case of the bigger the better. Starting currents peak very high, I've measured 250A on a 3GM30 without the benefit of a 'scope. Remember you have cold temperatures to contend with at times, possible long intervals between charging plus the consequences of the engine not starting! A small automotive battery of about 300+A will probably do the job.
Click to expand...

err?

Thats why I was proposing

Brand Exide
Range Exide Premium
Voltage 12 Volts
Technology Wet
Capacity (C20) 45 Ah
CCA (EN) 390 A
Length 237 mm
Width 132 mm
Height inc. terms 227 mm

Also there is always the domestic bank that can be switched in, in emergency. Thats 360Ah never discharged below 50%.
 
skyflyer said:
I plan to add a dedicated starter battery for my Yanmar 3GM30 but have two opposing issues:-

Firstly my house bank is flooded lead acid so all charging (mains, solar, advanced charger) is set up for that regime.

Secondly I am tight on space for the starter battery unless I get into a lot of expensive cabling and fettling to site it remotely, which tends to imply use of AGM or even LiIon

So can anyone recommend a physically small flooded lead acid with adequate CCA for starting what is after all a fairly small engine, by car standards!
Click to expand...

Smallest possible, which is what you asked for, but looking specifically at Exide batteries,
possibly https://www.tayna.co.uk/car-batteries/exide/eb356/

but if 220mm is too tall then a slightly lager footprint but only 175mm tall
https://www.tayna.co.uk/car-batteries/exide/ec412/


But what are you specifying as the minimum CCA ?

I beleive the Operation manual recommends a 70Ah battery , without specifying the CCA. That means one of these:

https://www.tayna.co.uk/car-batteries/exide/?ordering=&A-22=70,71
 
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