Battery Advice for 20hp OB

[mvweebles]

Good Day Peter, are you still having good luck with the battery choice you made?

No issues whatsoever so far. The re-purposed electrical all-weather box I mounted to my transom has gotten very wet a couple times due to comical beach landings and has kept the battery dry. Big test will be this coming October when we re-launch after sitting on the hard in Chiapas MX for 7-months. Wish I'd thought to disconnect the battery - will know more then.

But as of right now, I'd definitely buy the same battery. Small, light, no detectable self-discharge.

Peter

 

[Hippocampus]

Most of my past dinghies were 15-20hp. Current one is 40hp. But for all been told alternator output does vary some with load and rpm. Have no idea how important that is for LiFePO4.
Currently for most applications my battery decisions are based on cost and how many cycles you can get out of it. Although Li may make great great sense for a house bank where weight and total amount of usable stored energy per unit volume is worth extra expense continue to believe for most of us Pb still gives the best bang for a buck.
I’m an idiot and have filled the dingy with water more times than I like to admit. Being waked or taking a wave moored off a beach or not pulled up enough. I’ve even flipped one once. A fully sealed battery properly installed shrugs that off. I fully disconnect the dinghy battery for storage and leave it fully charged so haven’t had one freeze nor fully discharge. Might briefly trickle charge on a bimonthly visit on the hard but some storage places don’t allow any electricity brought to the boat. So even if it dies don’t see a big downside to buying a cheap new one replacing a cheap old one. So through the years will buy a AGM starter battery. I don’t equalize them so don’t care about brand. If I was only in protected waters that were speed restricted would think about going with flooded. The dinghy is our daily driver much of the time. Like to leave the big boat where is and explore with the dinghy so don’t view spending short money to drop in a new battery every few years. Will even load test and replace early.

 

[JustPlaneCrazy]

No issues whatsoever so far. The re-purposed electrical all-weather box I mounted to my transom has gotten very wet a couple times due to comical beach landings and has kept the battery dry. Big test will be this coming October when we re-launch after sitting on the hard in Chiapas MX for 7-months. Wish I'd thought to disconnect the battery - will know more then.

But as of right now, I'd definitely buy the same battery. Small, light, no detectable self-discharge.

Peter

That’s great to hear. I just purchased a brand new 20hp Suzuki with electric start for my 310 dinghy and I can’t find a good answer anywhere on if the lithium battery will work with the motors charging system and I don’t want to make a rookie mistake and fry something.

 

[Dougcole]

Good Day, I am curious what battery you ended up going with and what the outcome has been because I just purchased a 20hp Suzuki electric start motor for my 310 dinghy and would love to go lithium if possible due to weight.

I ended u going with the noco 900 (?) that I referenced above. It’s been a little over a year now and the battery has been flawless. Fires the motor off on the first push of the start button. Never seems to lose a charge.

Interestingly, I saw recently that Mercury recently purchased a lion battery company and sent out a shop manual addendum allowing use of lithium start batteries under warranty. Take that for what it is worth, I just saw it on YouTube somewhere. I can tell you for certain though that the noco works great on our 20 hp mercury.

 

[sealandsky]

I made a similar change last summer with a 25hp Yamaha electric start / power trim and also have a swim platform davit system. I selected an AGM garden tractor battery and so gar its worked great. I think I have 330 CCA.

 

[sealandsky]

I bought an AGM garden tractor sized battery (forgot the designation) for my 25 HP Yamaha with electric tilt. It works great and have never had issues starting the motor even after a couple of tilt cycles. It weighs next to nothing.