New outboard battery

[60DRB]

Hi all, been away a good while. Issues.
Bought a new 2024 Tohatsu 20 horse electric start outboard and am asking advice for a compatible battery. (I have temporarily parked the 1973 9.8 Mercury)
Requirements are 36Ah/5Hr or 40Ah/20Hr and 330CCA. I'm in south AL, so not often brutal cold.
What might be some good recommendations?

Thanks, Greg

 

[flatheadsteve]

Will you only be using it to start the outboard or will it also power other things?

 

[60DRB]

Will you only be using it to start the outboard or will it also power other things?

I’ve tried to answer twice and posts don’t appear.
This battery is only for engine starting.

 

[Ray Clark]

I have a 2021 Merc 20 HP electric start. Very similar to yours, if not exactly the same mechanically.

I have a Group 24 AGM battery; bought it at a local home improvement big box store. The battery has been service for three years now and is doing great. Not knowing better at the time, I bought a deep cycle marine battery and use it for starting. It looks like this:



The small Mercs/Tohatsus like the 20HP are very easy to start; I don't think you really need a high dollar battery. Enjoy the new motor!

 

[airshot]

Just be sure it is fully charged when your done with it. Leaving them partially discharged is what hurts them. If your only using it for a quick start, your motor probably charges it back up. Check it at the end of the day to be sure the charge is full...

 

[flatheadsteve]

I’ve tried to answer twice and posts don’t appear.
This battery is only for engine starting.

The requirements are pretty small a deka lawn mower/ atv battery would save money and weight. They make many different sizes I just installed one in a polaris atv that is slightly above those specs and was $60 at lowes.

 

[60DRB]

Ray, yes identical except badging and maybe handle/tiller bits.
Steve, OK.
So pretty much an auto type that meets spec is fine.
Thanks!

I’ll get a box for it too.

 

[LaqueRatt]

Just be sure it is fully charged when your done with it. Leaving them partially discharged is what hurts them. If your only using it for a quick start, your motor probably charges it back up. Check it at the end of the day to be sure the charge is full...

Not to be argumentative, but in my experience this is not true. Guess some people have a lot worse luck with batteries than I have.

 

[airshot]

Not to be argumentative, but in my experience this is not true. Guess some people have a lot worse luck with batteries than I have.

This is for deep cycle type batteries, every battery mfgr's instructions I have ever read say the same thing. Worked for a local battery mfgr company for about 10 years they preached about keeping batteries charged up for longest life. That is when I started using maintainers and my battery issues went away.

 

[moedelawn]

I bought a 35 ah harbor freight battery for my F25 and it is more than enough and I can use it for the trolling motor if I want to. I don’t remember what the cranking amps were exactly but it was around 450. I brought my tester because there is no rating on it being it’s a deep cycle.

It’s the offseason for that boat right now and I haven’t used it in months but the battery holds over 13 volts. Out of the 6 batteries I have on equipment it’s the only one I have not had to top off. It was $ 60.00 after a coupon. The negatives are it has a very short warranty and at two stores the batteries were already a year old. The guy swore that they had very little returns so I tried it. It’s an AGM battery and it’s strange to me that it holds such a high voltage.

I just put solar panels on 2 other batteries but I don’t have the need yet on this one

 

[60DRB]

Hi all, been away a good while. Issues.
Bought a new 2024 Tohatsu 20 horse electric start outboard and am asking advice for a compatible battery. (I have temporarily parked the 1973 9.8 Mercury)
Requirements are 36Ah/5Hr or 40Ah/20Hr and 330CCA. I'm in south AL, so not often brutal cold.
What might be some good recommendations?

Thanks, Greg

I bought a 35 ah harbor freight battery for my F25 and it is more than enough and I can use it for the trolling motor if I want to. I don’t remember what the cranking amps were exactly but it was around 450. I brought my tester because there is no rating on it being it’s a deep cycle.

It’s the offseason for that boat right now and I haven’t used it in months but the battery holds over 13 volts. Out of the 6 batteries I have on equipment it’s the only one I have not had to top off. It was $ 60.00 after a coupon. The negatives are it has a very short warranty and at two stores the batteries were already a year old. The guy swore that they had very little returns so I tried it. It’s an AGM battery and it’s strange to me that it holds such a high voltage.

I just put solar panels on 2 other batteries but I don’t have the need yet on this one

Hi all, been away a good while. Issues.
Bought a new 2024 Tohatsu 20 horse electric start outboard and am asking advice for a compatible battery. (I have temporarily parked the 1973 9.8 Mercury)
Requirements are 36Ah/5Hr or 40Ah/20Hr and 330CCA. I'm in south AL, so not often brutal cold.
What might be some good recommendations?

Thanks, Greg

I bought a 35 ah harbor freight battery for my F25 and it is more than enough and I can use it for the trolling motor if I want to. I don’t remember what the cranking amps were exactly but it was around 450. I brought my tester because there is no rating on it being it’s a deep cycle.

It’s the offseason for that boat right now and I haven’t used it in months but the battery holds over 13 volts. Out of the 6 batteries I have on equipment it’s the only one I have not had to top off. It was $ 60.00 after a coupon. The negatives are it has a very short warranty and at two stores the batteries were already a year old. The guy swore that they had very little returns so I tried it. It’s an AGM battery and it’s strange to me that it holds such a high voltage.

I just put solar panels on 2 other batteries but I don’t have the need yet on this one

I ended up getting a sealed auto battery for about $100, more CCA than needed but auto place couldn't find the one I bought online so upgraded for same $. Works fine-did first 5 hours of engine break in a couple days ago. I do use battery tenders on all my batteries for boat, lawn equipment, MC, etc.

 

[MrGiggles]

Not to be argumentative, but in my experience this is not true. Guess some people have a lot worse luck with batteries than I have.

A lead acid battery won't stay charged 100% for long, as long as it stays somewhere above half charged they should be fine. Letting them sit dead is what causes them to sulfate, and leaves them susceptible to freezing.

 

[airshot]

A lead acid battery won't stay charged 100% for long, as long as it stays somewhere above half charged they should be fine. Letting them sit dead is what causes them to sulfate, and leaves them susceptible to freezing.

Hmmm....mine stay charged for a month, above 90% anyway. During long storage over winter I monitor them and when they drop down to 12.5 I put them on a maintainer for a couple weeks.. If I have one that drips more, I leave it on a maintainer for a month or more and brings them back to life. My two deep cycle trolling batteries just dropped to 12.45 today, after sitting since Nov 15th. Topped up they usually read 12.8. My start battery has held 13.1 volts without any drop since Nov.
Batteries were all new in 2019....still goin strong