Battery? Deep Cycle v Starter?

[AZWIP]

Howdy, I have an 88 Seaswirl... has two batteries... I don't really know the history of one of them (the "Starter" one)... the Marine Deep cycle... is about 3 years old... I am thinking of replacing the "Starter" one... but instead of a another "Starting" battery... simply replacing it with another deep cycle marine... any issues with that that anyone can think of?

So, I'll have two deep cycle marine batteries instead of one deep cycle and one starter... pros/cons?

Lastly... with a car, you look up the motor and match a battery with make model and year.... am assuming I don't need to do that with my boat ??? Or... do I?

I have the OMC 4.3l 6 cyl. GM (Chevy) I think, OMC Cobra.

Any help and/or suggestions appreciated.

Ron

 

[wrench 3]

Two deep cycle batteries would do the job fine. However if your planning to use that battery strictly for starting and not for running accessories with the engine off, you mite as well use a starting battery. They're usually cheaper.
Car batteries are listed for application mainly for physical size so that they will fit into the space that the manufacturer allowed for it. Fitting one into a boat is a lot more universal. Like any battery, the bigger the better. But a small 24 series marine battery would crank that 4.3 no problem.

 

[KD4UPL]

Every engine, marine included has a minimum requirement for cranking amps. Automobiles are typically listed as Cold Cranking Amps which is rated at 0 degrees. Marine are typically listed as Marine Cranking Amps at 32 degrees. I guess they figure people don't start their boats when it's below freezing. Either way, be sure the battery will deliver enough amps to meet the engine's requirements. As small as that engine is I would think that a deep cycle would work just fine but I'm guessing. Many marine batteries are "dual purpose"; kind of a hybrid between a starting and a deep cycle. This is probably fine for your situation.

 

[jimmbo]

My Interstate Marine Battery has a CCA Rating of 800 and some other rating of 1000. It was new last April, replacing the 14 yr old battery that came with my boat. It too was an Interstate Marine Battery and tested as still having 75% capacity. If I had an outboard, I would still be using it, but a 5.7 has no provision for rope starting so...
As for using a Deep Cycle for starting, well we are told that Deep Cycle are engineered for long lower current discharges and be able to recharge fully and that they aren't engineered for short time High discharge rates. I've seen lots of tightwads using the Deep Cycle version for starting. Obviously it will do it, for how long, I've never gambled. Wired in Parallel 2 DCs would certainly provide ample current, but then charging two batteries like that often creates issues. I guess with switches, relays and isolators it can be done properly.

 

[bruceb58]

The marine "deep cycle" like the Interstate Marine are not true deep cycle batteries and will be fine to start your engine.

 

[jimmbo]

Just for clarity, My Marine Interstate Batteries were Starting/Cranking models not the Deep Cycle type

 

[dingbat]

I've seen lots of tightwads using the Deep Cycle version for starting. Obviously it will do it, for how long,

This "tightwad" has been using dual deep cycle (real) batteries (grp. 27) since 2003. "Tightwad" installed an ACR to manage the charging and distribution of said batteries. Very happy with the solution.

To answer your question...Life expectancy ~ 5 years

 

[jimmbo]

If you are using more than one battery, I wouldn't be calling you a "tightwad". If you were only using one Deep Cycle for everything including starting, then I would be calling you a "tightwad"

 

[bruceb58]

I was using the Costco "Marine Deep Discharge" batteries for many years to start my 7.4L carb'd engine. I probably wouldn't if it was EFI. Problem is, the Costo "Marine Deep Discharge" batteries(Made by Interstate) are not True deep discharge. They are a hybrid battery. I now use AGMs.

 

[jimmbo]

I've had AGM(Optima) batteries in two of my cars. Last winter, and this fall, I had an issue where the car wouldn't start. Would crank plenty fast, but wouldn't run. Replaced it with my boats battery and it seems to be fine. The other AGM sat a couple of years, and went totally dead. Never did accept a charge, even when using a second battery in parallel to fool the charger.

 

[bruceb58]

I've had AGM(Optima) batteries in two of my cars. Last winter, and this fall, I had an issue where the car wouldn't start.

Optima batteries are horrible. They used to be good but when the company got sold and they moved production to Mexico, their quality is no where near what they used to be.

 

[jimmbo]

The one totally dead was about 10 yrs old, sat for 6 yrs. The recent one was about 4 yrs old. I am impressed with Interstates wet cell Marine cranking battery. The one that came in my boat was 14 yrs old and tested by Interstate as still having 75% capacity last April. The guys at the local Interstate store kept looking at the battery date code, muttering it couldn't be 14 years old. For the first 8 years I didn't even remove it from the boat for winter storage. I had wires attached to the battery that were routed under the tarp where I could hook up a charger a couple of times during the winter. In hindsite, not the smartest idea in case the battery froze and cracked or out gassed enough hydrogen to risk exploding if there was an internal arc.

 

[dingbat]

Problem is, the Costo "Marine Deep Discharge" batteries(Made by Interstate) are not True deep discharge.

I see that...

I currently have a pair of Interstate Pro ECL (Pro-27M) batteries. Website shows them as discontinued and points you to the Interstate multi-purpose battery. Looks like I'm back to AC Delco Voyager (M27MF) when these give up the ghost.

 

[bruceb58]

I currently have a pair of Interstate Pro ECL (Pro-27M) batteries.

Yep...not a true deep discharge battery.

 

[AZWIP]

Hello again, thank you all for your replies and suggestions, I sure do appreciate it.

Ron

 

[QBhoy]

Depends on how reliable your engine is. Haha.
If she starts well, be no problem.
Probably worth noting that you can get batteries that are classed as starter and leisure capable.

 

[HT32BSX115]

I had an issue where the car wouldn't start. Would crank plenty fast, but wouldn't run.

That seems pretty strange.......I would venture to guess, if your engine cranked "Plenty Fast" but wouldn't start, it wasn't the battery, regardless of the type...........

I am now starting to look at "super" capacitors for starting (only)

You wire up a series network of (6) 3000F (farad) 2.7V capacitors to the "starter-side" of the starter-solenoid. Then charge them to approx 16VDC using a "charger" (even a solar panel if you want to bring your lunch!!)

When it comes time to start, you turn the key, the solenoid (powered by any regular battery, deep-cycle or otherwise) connects the capacitor network to the starter and "spins" the starter. After starting, the capacitors are recharged for the next start by a simple charger powered either by the battery or alternator. (an experiment using caps like this was tried on a 6.0L IHI diesel and the experimenter got 4 successful starts before needing to "re-charge" the capacitor network)

A starting system such as this allows for using gelled type long-life batteries that never have to provide HUGE starting currents. So they end up lasting a LONG time. It also effectively removes the potential for voltage spikes in marine electrical systems from starters and eliminates severe system voltage drop when cranking an engine.

I WANT ONE! (or I want to build one!!) http://www.maxwell.com/esm/

Cheers,

Rick