Batteries, again

Hi,

I'm looking at the 3 4d batteries on my boat and the mess-o-wires. The po used one of the 4d's as a starting battery. Is that kosher? What would the collective recommend as a starting battery for a FL130?

Cheers

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I'm using something that's equivalent to a Group 31...forgot the size...but if you have short cable runs...I'm pretty sure anything with at least 800CCA's will do.

I could never get a straight answer so I looked at it...if that size batt could start my 7.3 Powerstroke diesel in my truck...probably will handle the Lehman...

So far no problems after 3 months of cruising (FL 120) and sitting 4 months. Probably always better a dedicated "starting" battery than a mix of deep cycles...but I know if a big enough bank they work OK too.

Do you have a separate house and start batteries? I would have separate banks or at least able to keep the separate.

Are you back in the Seattle area?

Yes, back in Seattle. There is a battery switch and I can isolate the house and start. I have to get a meter on them to check condition, but the start battery barely turns the engine over. The wiring is a mess....I think I'm headed towards a project!

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I have two 4Ds in a starboard bank and one 4D in a port bank and one Group 31 exclusively for my generator. I anchor out once and a while and use the starboard bank as house. My refrigerator is the only real draw and it does a good job of depleting the batteries over night. I have a combine solenoid so I can still start my 160 HP volvo's in the morning. If for some reason this didn't work I could start my generator on its own battery and in short order my 40 amp battery charger would have everything back to normal. I have not yet had to resort to the generator.

I use a 4D for start on all diesels, a pair of propulsion engines and a genset. Has worked well, with long battery life, since I bought this boat in 94, at which time the existing battery was already getting old.
When I redid my house battery system I left the Start system alone as it was outperforming the house system.

If you don't want to muscle around a 4D...many boat manufacturers use a pair of group 27s or 31s in parallel. Every Sea Ray out of the factory was wired that way for many years on the smaller Cat and Cummins diesels...bet they still are.

As I said before...my 850CCA Walmat batt has been field tested now to my satisfaction so I'm satisfied...

If you are really unsure, call American Diesel maybe they can help...but when I called they gave me a amp-hour rating which didn't help me much. I'm sure if I had done more research it might have. So I resorted to the common sense approach of what diesels all around me are started with every day.

dhmeissner said:

Hi,

I'm looking at the 3 4d batteries on my boat and the mess-o-wires. The po used one of the 4d's as a starting battery. Is that kosher? What would the collective recommend as a starting battery for a FL130?

Cheers

Sent from my iPad using Trawler

Click to expand...

We asked Norm Dibble, who was the PNW Lehman guru (now retired), the same question when we rewired the engine room. 4D was his recommendation.

Boat came with 8-D's, but on the recomendation of Pacific Power Batteries, I eventually switched to four 4-D's, lead acid nothing fancy. If you have a generator you don't need massive battery banks.

With a good marine charger the batteries last about 10 years. No generator, then think about deep cycle for the house batteries. If you regularly draw down the house batteries hard, the battery life will drop as well.

Thanks guys, I'm going to keep it simple. But definitely go through and upgrade the 40 year old wiring.

Dave,

I went from an 8D to a group 31 to start the Perkins 6-354 in the old boat. Always started instantly. New boat has a 4D. When that goes the Cummins will get a group 31.

Your back will thank you.

Rob

I went from an 8D to a group 31 to start the Perkins 6-354 in the old boat. Always started instantly.

That is what most folks find if they do not operate in cold weather.

Cranking at 0F may require a pair of #31s to get going.

Well, the start battery is a goner. Also cleaned up some original faulty wiring.

I've wired the boat to have one of the remaining 4d's as the start and one as the house. Darn those things are heavy!

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FF said:

I went from an 8D to a group 31 to start the Perkins 6-354 in the old boat. Always started instantly.

That is what most folks find if they do not operate in cold weather.

Cranking at 0F may require a pair of #31s to get going.

Click to expand...

Fred,

I'm sure that's true but I will never be trying to start a boat in 0 degree weather!

Rob

Using group 31 (1 for port engine, 1 for starboard) with seperate house bank. Starts perkins 4-154s fine. Question: lookimg at moving one of the start batteries to make room for a larger holding tank. Would it be better to combine the two group 31s into one start bank for both engines?

On The Rocks said:

Using group 31 (1 for port engine, 1 for starboard) with seperate house bank. Starts perkins 4-154s fine. Question: lookimg at moving one of the start batteries to make room for a larger holding tank. Would it be better to combine the two group 31s into one start bank for both engines?

Click to expand...

As long as you can jumper or run cross connect to your house batts...you could get away with just one start batt for both engines...hook one alternator up to the start batt and the other to the house bank.

If you combine the 31's and they go dead...there's no advantage to having them together...and once one engine is started....a few seconds and some of those amps have already retuned to the batt from the started engine, plus the alt is helping start the second engine also.