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My old batteries are 24MS. Any reason not to use 24DC?

I'd go,larger (27) if my battery box would support it.

MS is a starting battery and DC is a deep cycle. Both are optimized for different uses (if you are buying quality batteries). Many of the discount batteries such as Wal Mart or auto parts stores don’t seem to be much different no matter what the label says

The "24" indicates it is a group 24 battery so they are both approximately the same size.

In this context the "MS" usually means "marine starting" and "DC" usually means "deep cycle". Both terms are primarily marketing terms and don't mean much else. It is not unusual for the only difference to be the sticker. The only other number that matters is the cranking capacity.

Car batteries usually list Cold Cranking Amps (CCA) and boat batteries usually reference Marine Cranking Amps. They both indicate the number of amps that can be delivered at a specified temperature for 30 seconds without dropping below 7.2 volts. For CCA the temperature is 0 degrees F and for MCA it is 32 degrees F.

The 24MS and 24DC batteries should be interchangeable as a start battery as long as whichever flavor cranking amps (CCA or MCA) matches the requirements of your outboard.

To avoid potentially unpleasant surprises, make sure that the posts are the same type and orientation as the original battery.

And these are Wal-Mart batteries

Maraquita wrote: ↑Thu May 29, 2025 5:03 pm MS is a starting battery and DC is a deep cycle. Both are optimized for different uses (if you are buying quality batteries). Many of the discount batteries such as Wal Mart or auto parts stores don’t seem to be much different no matter what the label says

Since our outboards can be started with a lawnmower battery, I have Deep Cycle batteries for both.

Thx, good to hear this.

Russ wrote: ↑Fri May 30, 2025 5:51 am Since our outboards can be started with a lawnmower battery, I have Deep Cycle batteries for both.

I carry a small jumper pack for emergencies.

I once jump started my truck with one of these when it was 5F degrees outside. Amazing how much power they can deliver.

I have 2 deep cycle batteries that I switch every year. The start battery is only connected to the motor and doesn't get much stress.

https://www.amazon.com/Nusican-Battery- ... KSVX5?th=1

Update: installed new 24DC batteries yesterday and splashed Soggy Paws. Merc 50HP started with no problem.

dlandersson wrote: ↑Fri May 30, 2025 6:53 am Thx, good to hear this.

Russ wrote: ↑Fri May 30, 2025 5:51 am Since our outboards can be started with a lawnmower battery, I have Deep Cycle batteries for both.

One thing to note.. is that MARINE GRADE batteries, have WELDED plates inside them.
This is so they withstand all the bounce/pounding.

If you go get generic batteries.. say.. from Princess Auto... or some low end brand, most are not welded plates inside them, and thus do not last long.


AD

Nice point. I did not know that.

adudinsk wrote: ↑Mon Jun 16, 2025 6:27 am One thing to note.. is that MARINE GRADE batteries, have WELDED plates inside them.
This is so they withstand all the bounce/pounding.

If you go get generic batteries.. say.. from Princess Auto... or some low end brand, most are not welded plates inside them, and thus do not last long.


AD

Russ wrote: ↑Fri May 30, 2025 8:40 am I carry a small jumper pack for emergencies.

I once jump started my truck with one of these when it was 5F degrees outside. Amazing how much power they can deliver.

I have 2 deep cycle batteries that I switch every year. The start battery is only connected to the motor and doesn't get much stress.

https://www.amazon.com/Nusican-Battery- ... KSVX5?th=1

I did the same this weekend. Those packs will save you!
KB

Hi All!

Those ‘Start Packs’ are great!
I got one for my daughter who has been in Montana the past couple of winters as a ski instructor.
(Boy does it get cold in those mountains!)
It has come in handy for her and her friends on several occasions in below zero weather (as long as she keeps it charged up and handy )

I really should get one for Over Easy and our van travels (before the tariffs Jack up prices )….next time I’m in Harbor Freight or Auto Zone.

We currently have a pair of marine “dual purpose” batteries from West Marine that have been working well for us.
One is about 4 yrs old and the other is about 2 yrs old.
I did have to top off the fluid levels with distilled water this year for the first time.
I check them annually but this is the first time I found it necessary to add fluid.
I think it’s because the off-season maintenance charger I used has a higher automatic current capability than the one used previously.
That sorta makes sense…..

We also have our batteries firmly strapped down and in individual battery ‘buckets’ to help contain them and any potential leaks should they become damaged. We currently have ours mounted on the port side in the seat aft of the galley on our Mac26X. It’s tight but still serviceable.

(With the galley and the A/C unit along with the batteries all on the port side we have a slight list to port. If/when we get the opportunity I’d like to either add additional batteries or move these batteries to the starboard side … wondering if anyone else has done this on their Mac26X?)

Best Regards,
Over Easy

OverEasy wrote: ↑Tue Jun 17, 2025 11:14 am Those ‘Start Packs’ are great!
I got one for my daughter who has been in Montana the past couple of winters as a ski instructor.
(Boy does it get cold in those mountains!)
It has come in handy for her and her friends on several occasions in below zero weather (as long as she keeps it charged up and handy )

Where is your daughter skiing? We live between 2 big Ski resorts. Big Sky is the millionaires' playground and Bridger Bowl for locals.

The jumper packs are cheap enough to keep on the boat and vehicles. Had to jump start a friend's car this winter with one. It was COLD but the thing worked like a champ.