Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 01-06-2018, 10:02   #1
Registered User

Join Date: Nov 2006
Posts: 18
Outboard Battery size

Hi!

I recently bought an older Honda 15HP four stroke outboard motor for our dinghy to replace an a smaller 6hp.

One of the features of the 15HP is electric start, which would be awesome to take advantage of. I currently have no battery or electrical system aboard the dinghy though.

Reading the manual, they mention to use a battery with a 40AH rating (no CCA given) as minimum. Looking at batteries it seems to me maybe this is a bit overkill? 40Ah you're starting to get at the bigger (and heavier/more expensive) batteries.

I was wondering if a motorcycle type battery would do? Something like 12Ah 200CCA? I mean they start up large motorcycle engines, surely they'd work with a small 15HP?

Thanks!
Thomas
__________________

mxtommy is offline   Reply With Quote
Old 01-06-2018, 12:27   #2
Registered User

Join Date: Jan 2017
Posts: 11,202
Re: Outboard Battery size

Those little lithium "jumpstarter powerpacks" now come powerful enough to crank big diesel engines.

Can recharge off 12V or mains plug overnight.
__________________

john61ct is offline   Reply With Quote
Old 01-06-2018, 13:08   #3
Registered User
 
Colin A's Avatar

Join Date: Mar 2013
Location: East of the river CT
Boat: Oday Mariner 19 , Four Winns Marquis 16 OB, Kingfisher III
Posts: 655
Send a message via Skype™ to Colin A
Re: Outboard Battery size

Small power sport/motorcycle batteries should work fine. Not sure exactly why but the ones marketed to lawn mowers with the same specs on the powersports batteries tend to be cheaper.
__________________
mysite: Colinism.com
Colin A is offline   Reply With Quote
Old 01-06-2018, 13:56   #4
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 25,463
Outboard Battery size

Iíd look hard at a SLAB or sealed lead acid battery, sort of like the ones used in exit signs etc, no vent caps and you canít spill acid etc.
Not sure if they are AGM or Gel?
a64pilot is offline   Reply With Quote
Old 01-06-2018, 17:59   #5
Registered User

Join Date: Jun 2013
Location: MA, USA
Posts: 7
Re: Outboard Battery size

Is there a voltage regulator on the charging circuit of the motor? If not, the battery size could be so you don't cook the battery charging it rather than cranking power needed to start it.
Lrak is offline   Reply With Quote
Old 01-06-2018, 18:08   #6
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 25,463
Outboard Battery size

At least the older outboards that I have experience with had very similar charging systems like older motorcycles. That is rectifiers.
Basically they made all the power they could and wasted the excess as heat, reason rectifiers are finned. Itís not much power either, they sort of trickle charge the battery. Of course they didnít cook motorcycle batteries.
Iíd assume even newer small outboards are similar? I know the bigger ones have automotive type alternators, but doubt the little ones do.
a64pilot is offline   Reply With Quote
Old 02-06-2018, 03:47   #7
Registered User
 
ranger42c's Avatar

Join Date: Aug 2012
Location: Maryland, USA
Boat: 42' Sportfish
Posts: 3,868
Re: Outboard Battery size

Quote:
Originally Posted by mxtommy View Post
Hi!

I recently bought an older Honda 15HP four stroke outboard motor for our dinghy to replace an a smaller 6hp.

One of the features of the 15HP is electric start, which would be awesome to take advantage of. I currently have no battery or electrical system aboard the dinghy though.

Reading the manual, they mention to use a battery with a 40AH rating (no CCA given) as minimum. Looking at batteries it seems to me maybe this is a bit overkill? 40Ah you're starting to get at the bigger (and heavier/more expensive) batteries.

I was wondering if a motorcycle type battery would do? Something like 12Ah 200CCA? I mean they start up large motorcycle engines, surely they'd work with a small 15HP?

Seems odd your manual would specify an amp-hour rating but not CCA/MCA.

Our dinghy battery for a 15-hp Suzuki 4-stroke is a small Deka "Outdoorsman" model , in one of the U1 categories.

Like from here: http://www.eastpennmanufacturing.com...Flyer-0008.pdf

Probably ours is the 11U1L, 350 CCA... since our outboard wants a minimum of 330 CCA (or 450 MCA, or 70 RC) per the Suzuki manual.

I would eventually look to see if there's an Odyssey AGM equivalent (size and cranking specs) just to reduce issues with self-disharge... since we don't run our outboard very often... but haven't gotten to that point yet...

-Chris
__________________
Selby Bay, South River, Chesapeake Bay, USA.
ranger42c is offline   Reply With Quote
Old 02-06-2018, 04:20   #8
Registered User
 
MV Wanderlust's Avatar

Join Date: May 2016
Location: Palmetto, FL
Boat: "Wanderlust" -- 1999 Jefferson Rivanna 52'
Posts: 717
Images: 27
Re: Outboard Battery size

We have a 15 hp Mercury with electric start. The dinghy came with a motorcycle battery in it and has been working fine. If it ever wears out, we'll probably replace it with the same.
MV Wanderlust is offline   Reply With Quote
Old 02-06-2018, 05:38   #9
Registered User
 
flyingfin's Avatar

Join Date: Oct 2016
Location: Cape Haze,FL
Boat: Carver,Cobia,Nacra, Columbia
Posts: 399
Re: Outboard Battery size

Or simply get a lawn tractor battery, usually under forty bucks, motorcycle batteries are more expensive
__________________

flyingfin is offline   Reply With Quote
Reply

Tags
battery, outboard, size

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Honda 15HP Outboard -- Fuse Size Between Battery and Engine? chasm Engines and Propulsion Systems 10 22-02-2018 08:42
Alternator size vs battery bank size benzy Engines and Propulsion Systems 24 24-02-2017 13:06
Engine size for boat size Astro2 Monohull Sailboats 54 20-12-2015 19:26
Elec. start outboard battery size FYI over40pirate Auxiliary Equipment & Dinghy 2 24-04-2015 06:01
Boat Size vs Slip Size Tscott8201 General Sailing Forum 25 23-08-2013 06:32



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 04:04.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.