Battery questions- Deep, Starting, Dual Purpose?

[TownsendsFJR1300]

I currently have a Duralast, group 27, starting battery (no issues).
(One battery on board so top of the line is preferred)

Spec's for my F150:


There is now a "Dual Purpose" battery available(see link below).

Of course there's also the Deep cycle battery.

The question, for regular operation (no *****ing electric motor), which battery style is the BEST (longest lasting, most dependable, of course within spec's)?

"Dual Purpose"
Duralast Marine battery - 12 months free replacement 24MD-DL - Read 4 Reviews on Duralast #24MD-DL

Actually, this, ^^, a group 24 appears to meet spec's required...


Thanks ahead of time.

Found this which explains a bunch: https://www.batterysystems.net/deep-...rting-battery/
but doesn't address the "dual purpose".


.

[scofflaw]

Duel purpose has been around for quite some time. My 2006 280 DA sundancer with twin v8's uses 3 of them. I get about 5 years of service from them. Don't do a lot of overnights and have a genny on board. Suits my needs for that boat. Not really sure what your question is about them

[oldmako69]

https://www.amazon.com/Boatowners-Me...s=nigel+calder


Nigel Calder has a few things to say about batteries in his book. If I recall correctly, he says that there are only two types of batteries - Crankers and Deep Cycle. He goes into detail explaining why this is true (the batteries internal construction) and why choosing the right battery is essential to guarantee long life and getting the most amperage out of a battery when you need it.

He then goes on to say why a dual purpose battery is nothing more than a marketing gimmick and that a dual purpose battery is good at neither function, starting or deep cycle. It makes a lousy cranker, and it makes a lousy deep cycle if used for either purpose exclusively and repeatedly.

Now, a caveat to the above is that *** this is fairly old information*** as my copy of the book is old. And, that batteries have changed over the years. Today's batteries may contain special juju or simethicone and can do both equally well. I do not know.

I think a lot of it really depends on determining what you want to do with the battery. My last boat had a single engine and was loud as hell while at idle. As a consequence I used a Cranker and a Deep Cycle. I started on the cranker and then switched to Both. On the hook while fishing, I switched to the deep cycle only, to save the cranker for getting home.

This boat however idles so quietly, that an argument can be made to keep one running while on the hook in order to keep the voltage flowing into, rather than out of the batteries. So that negates the need for a deep cycle.

From what I recall, the best way to kill a cranker (aside from sulfation) is to run it dead (repeatedly). And the best way to kill a deep cycle, is to ask it to start an engine (repeatedly).

Batteries, like motor oil are a great topic for vigorous and acrimonious debate. Have at it lads.

[scofflaw]

As many years with boats that I have had, I've never had a problem with using a deep cycle as a starting battery

[TownsendsFJR1300]

The link I posted at the bottom of my first post pretty much says the same ^^.

Starting batteries have more initial "ump", deep cycle for your *****ing motor. Lower cranking power(but longer) vs the "starter".

My question about Dual Purpose is I've never heard of one and looking on the net, not much info about them..

***There was also discussion (I think RB brought up), certain batteries (Optima maybe?), should NOT be used with certain Yamaha engines. That it can cause issues to your engines charging system.***

[oldmako69]

As many years with boats that I have had, I've never had a problem with using a deep cycle as a starting battery

One day you might have an engine that is a bit recalcitrant and requires multiple start attempts. That might be the day your deep cycle batt lets you down. I think that might be Calder's point. My post did not do his chapter on batteries any justice at all, its merely my recollection of what he wrote.

[Jason2tpa]

Choosing between the dual purpose or the standard deep cycle or gel comes down to the accessories you want to power and how long you normally supply power to them.

I could see the value of having the dual purpose battery as the vessels sole power supply IF you rarely boat at night, do not have a *****ing motor, or baitwell, and your boat is not equipped with numerous digital gauges. In essence, you're a simple boater, joy rides.

Otherwise, I believe it goes without saying you should have 1 deep cycle/gel strictly for cranking. My other 2 batteries power my 24v *****ing motor, baitwell pump, nav lights, acc lights, gauges. If I spent a day on the water fishing, these 2 batteries get put on the charger. My cranking battery has never been charged, over 3 years it continues to hold peak charge.

My 2 accessory batteries are Interstate SM24. No problems so far.

Interstate Batteries | Marine Battery | Deep-Cycle Batteries | Watercraft Batteries | Marine AGM

[fairdeal]

From what I recall, the best way to kill a cranker (aside from sulfation) is to run it dead (repeatedly). And the best way to kill a deep cycle, is to ask it to start an engine (repeatedly).

Here's some things that Calder actually wrote:

[oldmako69]

I read that 20 years ago. Clearly my reading comprehension and retention suck.

[fairdeal]

Clearly my reading comprehension and retention suck.

nah, just the subliminal effect of seeing countless internet forum posts claiming
"you can't use a deep cycle for starting, it will damage it"

[boscoe99]

nah, just the subliminal effect of seeing countless internet forum posts claiming
"you can't use a deep cycle for starting, it will damage it"

Are you referring to TOS? The Other Site being The Hull Truth?

Have you ever read so much crap from so many in so short a period of time?

Not only will a deep cycle be damaged if used for starting but I have read that if it is charged at the same time as a starting battery then both are likely to seriously damage themselves and the charging system.

Oh, God forbid that a terminal be soldered to a battery cable. That is the kiss of death.

[TownsendsFJR1300]

Ok, as asked earlier as well, what battery was it that RB (think it was RB) mentioned was NOT good to be used on a certain Yamaha engine?


I believe it was for one or two type systems...

RB seems to be on vacation, anyone?

[99yam40]

already drank a couple of beers and can not come up with the name of battery, but it was one of the newer, expensive, spiral wound ones. I think

[TownsendsFJR1300]

already drank a couple of beers and can not come up with the name of battery, but it was one of the newer, expensive, spiral wound ones. I think

Optima?...............

[99yam40]

I believe that was the one.