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Starting battery SMALLER than Group 24?
Posted: Sat Jan 13, 2007 4:39 pm
by kabauze
I'm about to replace the starting battery in Nevermind and would love to hear from anyone who has successfully used a starting battery smaller than Group 24 with their inboard diesel. Group 24 is actually pretty large - at least in the tight confines of a Triton. If I can find a small enough starting battery, maybe I can stash it under the port galley instead of under the companionway steps. That would free some space for something else.
The engine is a Westerbeke 10-Two - two cylinder, 10HP, 450cc, 20:1 compression. The service manual isn't too helpful - it only specifies a '60 Amp-Hour battery". Huh? At what discharge rate?
I've had a 550 CCA Group 24 in there and it has turned it over OK when charged, but it's been on its last legs for a while.
Thanks in advance for the advice!
battery
Posted: Sat Jan 13, 2007 6:17 pm
by The Good Goose
I have a 1 cylinder yanmar and I use a rolls 1 2490 xj series 3000
it has 520 cca and 90ah and 165 res it is 49 pounds and about the same size as a car battery.
It starts the engine well if it is charged. I tend not to use the engine much so every once in awhile it gets discharged.I don't have two batteries so It's easy to discharge it if I'm not careful. I then have to use the compression release. It's dimensions are 6.5"wide 11 long and 10high to the top of the terminal bolts.
Brock
Posted: Sat Jan 13, 2007 11:01 pm
by bcooke
'60 Amp-Hour battery". Huh? At what discharge rate?
The amp hours rating is supposed to the calculated discharge rate. In theory, 60 amps for one hour or 1 amp for 60 hours... or 15 amps for 4 hours... or some other product of time in hours and amperage that equal 60 in your case.
It doesn't usually work out in practice but it is the standard way of rating batteries.
For a starting battery, amp hours are not too important. What is important is the CCA or cold cranking amps. This is the (again theoretical) maximum discharge rate of the battery. The more amperage, the more power to the starter motor and the better (faster) engine cranking.
-Britton
Posted: Sun Jan 14, 2007 12:20 am
by dasein668
I'm using a Group 57 (I think) with good results. 8.5 inches x 7.5 inches x 12 inches; 520 CCA. It's been more than sufficient for my 2GM20F. I picked it up off the shelf at my local Sears.
My electrical/batteries
Posted: Sun Jan 14, 2007 1:35 am
by Jason K
I'm using a Group 57 (I think)
That sounds more like a Group 27.
Posted: Sun Jan 14, 2007 8:54 am
by dasein668
Could be. I didn't really pay too much attention to the group number. I do know that it's quite a bit smaller, physically, than my house batteries which are the standard Group 24 size.
I went with that size so that I could fit it into the dead space behind/under the galley unit. There is plenty of room in there for a large batter, but the clearance between the bridge deck and the galley shelf, as well as through the existing opening in the counter.
It has worked well for the past two seasons.
Posted: Sun Jan 14, 2007 9:52 am
by Tim
Diesels require some significant cranking amps to turn over. You also want enough excess capacity to help with a somewhat discharged battery--a common thing, of course. Higher amps (CCA rating) is always better for a diesel. Most diesels really like to have their flywheels slung around by an enthusiastic starter motor. The older and heavier the engine, the more cranking amps it probably requires.
You can use any battery that will effectively crank your engine. If you want to go small, this may require trial and error. Either way, for a dedicated starting battery ignore the amp-hour ratings and concentrate only on cold cranking amps.
I am not sure exactly what Nathan's battery is, but it is definitely not a GP 27.
Posted: Sun Jan 14, 2007 11:03 am
by dasein668
As I said, I don't exactly know?nor particularly care, frankly! hehe
I went to Sears with a tape measure, knowing the dimensions I needed the battery to fit in, then bought the most CCA I could in the package that would fit the space.
As an aside,
here is a list of Group Size measurements.
Posted: Mon Jan 15, 2007 3:05 pm
by Ceasar Choppy
I use the Odyssey PC1200 for my Perkins 4-108. It has a smaller footprint than a Grp 24, is lighter, and works a treat for every crank.
Previously, I needed a minimum of a Grp 27 to start the Perkins.
If you are looking for something around a Grp 24, you can probably go a size smaller like the 925. It is an AGM so I can mount it practically anywhere. Oh, and they have a rally nice tray/holddown that you can get for it too.
Specs here:
http://www.odysseybatteries.com/batteries.htm
Posted: Mon Jan 15, 2007 9:31 pm
by Mark.Wilme
I have the space so I am installing2 x Trojan Gp 27's in the spring ($80 each at batteriesplus) and switching them, the goal being that both are always fully charged but one is always off-line so I can't drain it down. This is in addition to the house bank which will be 4 x T105's.
I don't intend to be caught with a flat starting battery :)
Followup...
Posted: Mon Jan 22, 2007 2:45 am
by kabauze
OK, as a followup, I'm posting to describe what I ended up with. I took Nathan's approach and headed to the local Sears. I stood in front of the wall of batteries for a while until I saw a few that were the size I was envisioning, and then I selected one with enough CCA to turn my engine. Simple.
The battery I ended up with was a Group 26, standard lead acid, 450 CCA.
It also has a large "C-8" printed on the front for unknown reasons.
It fired the 'Beke right up this afternoon and I went for a short motor around the harbor in the So. Cal. sunshine.
Thanks, Mark, for helping get these image tags working...

Posted: Mon Jan 22, 2007 11:33 pm
by Mark.Wilme
You should change your links to :
Code: Select all
[img]http://lh6.google.com/image/todd.r.bryan/RbRaI1XC3xI/AAAAAAAAAY0/YBsIFNWEU6Y/DSCN3568.JPG[/img]
[img]http://lh6.google.com/image/todd.r.bryan/RbRaP1XC3yI/AAAAAAAAAY8/fTVMQuzmGE4/DSCN3569.JPG[/img]
Big Brother wrote:Extra-large photos removed for sanity. They were the same photos that are visible at normal size in the post above.
HOWEVER
There is something about those google domains that appear to prevent them being embedded, if you open them in another window first so they are in cache then they will show if you refresh your forum page.
sorry I can't help more
Posted: Tue Jan 23, 2007 7:25 am
by Tim
I'd prefer to limit picture size to under 800 pixels in the largest dimension, since larger ones (even with screen resolution set to 1280 pixels wide) cause a need in this forum software to scroll sideways to view pictures and to read the text. I don't think anyone likes scrolling around to read or view pictures.
I can only imagine how frustrating it must be for those users using 800x600, or the more common 1024 x 768.
I prefer not to edit people's posts, but I did remove two very large photos from the post above, as noted. 800 pixel width is a good compromise here between screen viewability and reasonable size in order to see detail.
Thanks for your consideration!
Posted: Tue Jan 23, 2007 9:58 pm
by Mark.Wilme
Sorry Tim, I am running 1600 x 1200 and I didn't even think about that.
My bad
Tsk, tsk.
I'll consider myself admonished.
I wonder if there is anything you can do server side in php to automatically scale down images ? A call to ImageMagik or some other like software would do the trick and could be done dynamically (I used to use a script called QDig that would do that for you dynamically but I only integrated and adapted it into some html, I never understood how it worked)
Posted: Wed Jan 24, 2007 7:32 am
by Tim
Mark.Wilme wrote:I wonder if there is anything you can do server side in php to automatically scale down images ? A call to ImageMagik or some other like software would do the trick and could be done dynamically (I used to use a script called QDig that would do that for you dynamically but I only integrated and adapted it into some html, I never understood how it worked)
For the others who didn't understand the above, here is my translation:
I think we'll try to get the new post icons working before we think about adding any dynamic scripts to someone else's software code! (Right, Nathan? hehe)
Posted: Wed Jan 24, 2007 9:38 am
by dasein668
If Mark thinks he can decipher WTF is going on with the posts, he should feel free. I'm at wits end. No one at the phpbb support forum seems to have any ideas either. It most assuredly works if you log out every time. But if you stay logged in, all bets are off.
Posted: Wed Jan 24, 2007 9:40 am
by dasein668
As for automatically resizing photos, there may be a MOD available through the phpbb community. A pre-built MOD would likely be easier to implement than building our own.
FWIW, I wouldn't mind having something like that. I now size all my pics for the web at 1024x768 and don't really want to have to upload a specific version for the forum.
Posted: Wed Jan 24, 2007 12:00 pm
by Tim
I agree that auto resizing would be a nice feature. I doubt we'll see it here anytime soon, though.
1024x768 images work OK here as long as one has their screen resolution set at at least 1280x1024. The most common screen resolution used seems to still be 1024x768, which is too small to allow a photo of the same size to display in the text box of this forum; this size photo will force side scrolling for users at 1024x768 and below. This is why I suggest a maximum photo size of 800 pixels wide, which will fit cleanly for most users.
I resize my photos specifically for use here, as my "stock" resizing resolution is typically larger as well. It's a moderately annoying, yet strangely non life-threatening, step that I think is worth it to make things easier for the reader.
I should add that this is all getting unintentionally off topic for this thread, so any further discussion of these sorts of issues should be handled elsewhere on the forum. Sorry for the unplanned hijack, Todd!
Posted: Thu Jan 25, 2007 5:26 am
by Mark.Wilme
I am just about to leave for the airport but when I get the time I'll take a look at that PHP script I referenced and see if there is anything with ti that can be used.
I agree Nathan, we need the mystery of the new posts icon resolving before anyhting new is added, that's very odd.
Posted: Tue Jan 30, 2007 12:33 am
by Mark.Wilme
Nathan, Tim
That script that dynamically resizes images is available via sourceforge - the home page is :
http://qdig.sourceforge.net/Qdig/AboutQdig
Although it's PHP I am unsure as to how to integrate it into PhPbb. However I have a version of PHPBB up and running on Apache and if I ahve time next week whilst travelling on business (hotels and planes) I'll see if I can take a look.