Battery questions- Deep, Starting, Dual Purpose?

[rodbolt17]

I was in Mobile AL.
my mom is not well.

anyway I have seen several dry cell batteries burn hole in them with older bigblock 2 strokes.
myself I have used the dual purpose batteries over 20 years and never had an issue.

but that is why we undrdrove altenators in HP cars.
outboards tend to run at close to max RPM.
this generates a lot of current.
this can lead to boiling out the electrolyte.
that is why maint free batteries and not recommended.
Yamaha put out a list of engines that can use the AGM style batteries.

[boscoe99]

Sorry to hear about your mom. We wish her well.

[TownsendsFJR1300]

Plus 1, ^^, hope your mom is doing better....

[rodbolt17]

thanks
but it is end stage kidney failure and stage 4 liver cancer that is spreading.
I see another 19 hr road trip in the near future.
I left mobile Friday about 7 am,pulled into my drive about 1 am.
my eyes feel like a windshield,bug marks and all.

[Jason2tpa]

Man, so sorry to read the tough news RB.

[rodbolt17]

most marine manufactures specifically state not to use maint free batteries.

my batteries in my seapro are about 9yrs old and still going.
they are mounted in the CC.
I do pull them and top off the water with distilled water.
I do get in trouble sometimes if I use the water from my wife's C-pap thing .

yea I know they are on borrowed time but they function and load test fine.

[TownsendsFJR1300]

My current, Duralast, group 27, STARTING battery was installed 4-24-10(104 hours on engine) and still passes a load test. (didn't realize it was so old)... Cranks up just fine with minimal voltage drop...

Just that battery on-board, aft.

I do use this C-tek charger maybe once a week:
Battery Chargers - CTEK Battery Chargers Multi US 4.3, that IME (seven years) works quite well.

[99yam40]

as long as you keep at least one good battery on board, you should be good.

Use to you had a rope in case of emergencies,
sure would hate to try to pull start on of the big motors now a days

[oldmako69]

I routinely get at least 4 years from my batts. But, I keep after them. I keep the terminals spotless, pull them in the dead of winter and keep them charged. They're too expensive to neglect. I also buy the biggest ones I can cram into their spot.

[TownsendsFJR1300]

If you want to be out on the ocean with 7 year old batteries, that's up to you. But, if you hear a "click, click, click" one time on your 7 year old battery, and have to get towed home or worse, you are playing with fire IMO.

If it fails, it'd likely be on a cold start up, IE on my lift, in the water(in the back yard-when the oil is thick, takes slightly longer to start cold).

Worse case scenario, it doesn't start. It's NOT a fire or any other potential dangerous issue...

Besides load testing it, I watch the cranking voltage and it's right up there...

When the voltage starts to drop, it'd be replaced. That's why I started this thread, what's best as a replacement battery.. (seems what I already have)

Got 7 years out of my OEM Toyota battery. Slow crank one day, it's time...

And I do carry top of the line jumper cables on board along with tools, shop manual, spare primer bulbs, fuel filter, etc...

Never been stranded on my boat (or past other boats) due to any failure-preventive maintenance and simply keeping up on it..

[99yam40]

I often wondered if one of those new jump packs that fit in you hand would be something to carry in tool box on boat and truck . just in case

[TownsendsFJR1300]

I often wondered if one of those new jump packs that fit in you hand would be something to carry in tool box on boat and truck . just in case

It would probably work...

I don't really want the extra weight, nor have the space.. As noted, between knowing the health of my battery, paying attention to your voltage in the dash. It shouldn't be an issue.

I may run 15 miles off shore once in a great while, but mostly "inland". IE jumper cables would work fine... And even if offshore, there's a very popular reef out there (Edison Bridge Reef) for fishing and scuba diving so there's almost always another boat (or several) out there...

Not noted earlier, the smaller group battery will just barely meet spec's. I have a group 27 which is LARGE for this engine..(it's not borderline-power wise)

[99yam40]

It would probably work...

I don't really want the extra weight, nor have the space.. As noted, between knowing the health of my battery, paying attention to your voltage in the dash. It shouldn't be an issue.

I may run 15 miles off shore once in a great while, but mostly "inland". IE jumper cables would work fine... And even if offshore, there's a very popular reef out there (Edison Bridge Reef) for fishing and scuba diving so there's almost always another boat (or several) out there...

Not noted earlier, the smaller group battery will just barely meet spec's. I have a group 27 which is LARGE for this engine..(it's not borderline-power wise)

those li-on ones do not weigh much at all, the lead acid packs are heavy