bertram31.com

Crows Nest has DD 8.2s, and I switched from 8D batteries to Sear Diehard Platinum AGM that had 1150 cca. 2 1/2 years later, they both test "bad" at Autozone, and 1 tests bad at Sears and the other tests good, although it also test to 750 cca, which doesn't do me any good. Its Sunday, and the guy at Sears had no idea what to do because they don't sell the AGMs anymore and the biggest battery they had was about 750 cca.

What's the latest recommendation on batteries? I'm thinking of getting regular lead-acid group 31s that have about 950 cca and cost $120. Gonna' wait until tomorrow and see what Sears will do--both batteries have a 3 year replacement warranty and they're both within the warranty period.

John F. wrote:Sears had no idea what to do because they don't sell the AGMs anymore and the biggest battery they had was about 750 cca.

The fact that they don't sell batteries in this size anymore is THEIR problem...

John F. wrote:both batteries have a 3 year replacement warranty and they're both within the warranty period.

Is that a FULL warranty or a pro rated (after the first 12 or 18 months) warranty?!...

Having said that, you really should investigate what caused these batteries to go south... How do you charge them?!... Is your charger fully functional?!... Is your charger compatible with AGM batteries?!...

John

Use two group 31's to start each engine. So you will need 4.

Tony

John,
I ran 3-group 31 batteries in my 31 Express . 1 for each engine and 1 for the house battery. I had big block gassers for years, make sure your alternators are good, battery terminals are clean and tight and your battery charger is working properly. If you have diesels the 8D's are the way to go.
Pete Fallon

Speaking of alternators, is there any way to get them to kick in under 12-1300RPM? When trolling they don't activate.

Joseph Fikentscher wrote:Speaking of alternators, is there any way to get them to kick in under 12-1300RPM? When trolling they don't activate.

We used to run smaller pulleys on the alternators for my dads boat.


Mine...if going real slow for bass. I'm usually on one engine anyway...so I bump the other one up to charge.



I just re-read...12-1300 they should be kicking in before that, no? What it you bump them up a and bring back down...still not charging at that point? On my boat they kick in around 1000-1100 and can usually bring down to about 800-850 before they stop charging, if not I'll go through the connections...I usually find cleaning the ground helps the most. Could be coincidence...
I've had boat so long...I may have changed my pulleys too...so maybe 12-1300 is right. But that's fast for me...I might do that offshore.

If I bump them up they will both charge, but after idling for a while at 1000 or less for bass and blues they stop. Constantly checking the gauges. Last outing the house battery got so low that the electronics cut out. around 9.7 or so. Of course I forgot to check the gauges and trolled about 30 miles. Maybe I'll try to get some smaller pulleys. That's a good idea.

Joe

It's the built in voltage regulator. My father used to call them lazy alternators. Mine do the same thing until I get them warmed up. Then they charge out of gear or in gear at idle no problem.

Only solution is to get them rebuilt or replace them. Or as Pete suggested, a smaller pulley to make it spin faster.

I would cheat and put on a smaller pulley.

Pete

With John,s DD he probably needs two groups. 31's to match one 8d. If you pull the batteries for the winter the 31 is the way to go, much lighter than trying to handle an 8d.

When I bought my 31 it had two AC Delco 4D to crank the 454 Crusaders. Each battery serves one engine and half house. I do not run a generator.

I still use the 4D's which rate as follow:

Cold Cranking Amps (CCA): 1000-1050
Cranking Amp (CA): 1290
Reserve Capacity (Ah): 290-295

My question is if I can install, for example, two Optima Bluetop D31M's which rate at 75 Ah and 900 (CCA) and get away with it. I'm looking for options because those 4D's are heavy as hell and I do not want to hurt my back!

Sorry to intervene, but we call batteries by their amps only; for example 100 amps or 90 or any other number, in amps only.
Could someone please explain what 31's or DD's or 4D's or cca's are?
Also, HOW can you tell by reading your rpm's if your battery charges or not? When I turn my engines on, the volt meter goes to 13+, I'm up at the bridge so how do I tell if they still charge?
Elementary my dear Watson you may say ...

Huesso

Before we put in the Cummins, I was spinning over Mercruiser 454's with a group 31 for each engine. We ditched the 8D's years ago.

Yannis wrote:Sorry to intervene, but we call batteries by their amps only; for example 100 amps or 90 or any other number, in amps only.
Could someone please explain what 31's or DD's or 4D's or cca's are?
Also, HOW can you tell by reading your rpm's if your battery charges or not? When I turn my engines on, the volt meter goes to 13+, I'm up at the bridge so how do I tell if they still charge?
Elementary my dear Watson you may say ...

Yannis

http://www.interstatebatteries.com/m/ca ... e/starting

http://www.interstatebatteries.com/m/ca ... /deepcycle

We group them by size, which means Group 31 batteries have a certain dimension and have cranking amps. The amperage based on the size is also based on their function. Such as starting only or deep cycle which would be used for a House battery. The link above might help you see how they size them.

Now as far as how you know it is charging is a good questions. If you are showing 13+ volts on the volt meter means the alternator is working and the battery should be charging. However, if the battery is bad, it may not accept a charge. What usually happens in that case is you are using the boat, car etc. and you run it for lets say an hour. Shut it off and lets say 30 minutes later you go back to start the vehicle and the battery is dead. You can jump start it but that does not mean it will hold a charge and start the vehicle again.

Now if the volt meter does not show 12.5 to 13.6 volts then the alternator is not working and the batteries are not getting a charge. Or, you may show 13 + volts on the gauge, but you might be running too many electrical items and while it is charging, you are drawing more amps than what the alternator is putting back into the battery and eventually even with the engines running, the battery may go dead.

That is why an Amp meter is also important on a boat. Mine originally came through with an amp meter and not a volt meter. I was able to always determine if the battery was draining this way or if it was building up a charge.

Confusing yes. If this is not clear let me know and I will try again.

CCA means "Cold cranking amps". MCA means "Marine cranking amps".

Thanks for the advice and an update.

After a few days, Sears agreed to give me a Sears gift card for my purchase price of the battery (about $230). That was after turning down their offer to give me a Group 31 rated at 700 CCA about 5 times. I bought new, cheap Deka Group 31 lead acid batteries. See how it goes.

John

Just for a future FYI, if you can get up to the Deka plant, they sell blemish's at a discount. Usually you can't find the blemish.

Thanks Tony and Rawleigh.

I understand the size parameters as per your links.
I would consider the amps more important as a definition term for a battery, though.
As for the amperometer, youre right, it should be very useful; I might (one day) install this multimeter that except for the amps available, it shows a bundle of addl info, such as battery useful time left with current consumption, charging speed from my solar pannels, etc. It will be included in the 2018 long term plan !

I have 2 31 group for my engines
and a 4 d for the house
can back feed from any direction if need be
I have been using interstate they hold up nicely

There was a big discussion on batteries on a farming site I frequent. The consensus is that Cat or Motorcraft batteries are about the best.

Rawleigh

Believe it or not there are only about 4 manufacturers lot batteries. They make them for everyone to individual specs and then just slap on the right label.

Faithful,
I used to use Surrette batteries that were made in Salem Ma, best battery you could find anywhere, one of there group 31 Marine batteries weighed over 70 pounds. Back in the 70's & early 80's I ran 3 group 31's in my 1961 express that at that time were running 440 Chryslers. They lasted for 7 years in the New England atmosphere. The original owner John Surrette died and his grandson took over the business and moved it to Ft. Lauderdale somewhere, he made them under the name Rolls Batteries, I don't know if he is still in business but they were great product. I found that your lucky to get 3 years out of batteries in the Florida heat. My cars both Cadillac's would go exactly 3 years before the OEM Delco's would die. I switched to Interstate and got 5 years out of the last batch. The boat used to get about 4 to 5 years before they started going bad.

Uncle Vic had a magic potion that he got from Judge Trey, something that was used in the aircraft industry, maybe someone can post the name of the stuff that he used.

Another thing is to keep the batteries in your boat as cool and dry as possible, mounting them outboard inside the engine boxes works for some but I found mounting them between the boxes works better, easier to get to for service, but they should be up high as possible so they don't get flooded out if you do a lot of hard backing down on large fish. The original battery boxes were down in the bilge, just in front of the cabin door bulkhead, in a fairly small fiberglass box. I moved them up over 12" to a shelf I built out of FRP that was mounted to the outside of the main stringers, I mounted my 2 Guest rotary battery switches in the same area to keep the wiring run as short as possible. This mounting works for both the old style 2 piece lid engine boxes and newer style single lift back boxes.

The main thing is to keep the batteries no matter what brand or size, as cool and dry as you can they will last longer and you will save a lot of back aches I the future.
Pete Fallon

Pete Fallon wrote:The original owner John Surrette died and his grandson took over the business and moved it to Ft. Lauderdale somewhere, he made them under the name Rolls Batteries, I don't know if he is still in business but they were great product.

Rolls Batteries are still in business... But they're very much the Rolls-Royce of batteries and their prices are commensurate with that position... When I was pricing 8 x 8 volt batteries they were much more then double the cost of Deka equivalents... Almost triple IIRC...

Optima Blue top Marine batteries. A little more $$ up front but got ten years and probably would have gotten more but my excavator severed the power line to the dock and I didn't know it for two months. These batteries served my Cummins 6BTA's without fail.

Pete,
The product you are remembering was VX-6 from J. C. Whitney.
No longer available from them.
Today a product called Battery Equalizer, found at: http://www.batteryequaliser.com is the successor.

Have you tried it yet?

I tried the stuff from JC Whitney on my 1st car years ago when battery started to get weak and I had a bad case of Funds R Low.

I'd give a trickle charge in morning to get car cranked up then it was usually fine the rest of the day. But I still tried to parked at the top of inclines..just in case. Got her rolling and popped the clutch.

Bought the Whitney stuff and poured in battery. A few more mornings needed a charge to get enough cranks to start car. Then I was able to get enough juice to just get car started on its own then after awhile it was like the battery never had a problem. I will say that it was a little 4 cylinder motor that could have cranked over with a hamster wheel. But I never had to buy a battery and kept another year or so. I thought it was a miracle product...bought it for one of my next cars and saw little if any difference. Maybe too far gone, I was patient enough to let the stuff work or motor bigger and needed more...