# Smallest battery for outboard elec start?



## Dillusion

Whats the smallest and lightest (size as in dimensions, and weight) battery that can be used to start an outboard which has electric start? It would be used on a 15HP merc.

I'm thinking one of those small/half size odyssey batteries? But I dont know what rating would be the smallest. Weight is a concern too...dont want to shove a deep cycle trolling battery back there.


----------



## AfterHours2

A small Odyssey should be perfect for a 15. They are sealed and very lightweight. I use one and it powers my Lenco tabs and electric jack plate plus nav and led lights. I don't have electric start or charge on my motor and it has never been drained in a single session. Here's the one I use: 

http://www.amazon.com/gp/aw/d/B0002ILK6I/ref=mp_s_a_1?qid=1352082070&sr=8-1&pi=SL75

Good price too. Mine was from 07 and I just replaced it a month ago. Bought mine from Batteries plus and payed about $50 more...


----------



## iMacattack

Get the CCA (Cold Cranking Amp) specification from your outboard manufacture for the engine you have and match a battery to it. The "smallest" may not be the best. Yamaha for example requires more amps than some other outboards. You will end up frying the battery.

Capt. Jan


----------



## fultonswimmer

Odyssey 625, weighs in at a stealth 12lbs. Used for electric start, tilt, bilge on 20hp Tohatsu and never once taken it down to less than a need for a minimal "pop" recharge(using Odyssey charger about 10 mins.). Pricey but well worth it. They use these batteries in Alaska to start up airplanes in -50 degree weather so they can be depended on!


----------



## cutrunner

Braille batterys.


----------



## Creek Runner

Just a thought, my flouder gigging boat I run the ele. start off my trolling motor battery, it's a group 27 and I have never ran it down where it would not crank my engine. Also I assume your 15hp has a pull rope so if it did you have a back up. 

Not sure if you have a trolling motor but if you did you could kill 2 birds with one stone.


----------



## Dillusion

> Just a thought, my flouder gigging boat I run the ele. start off my trolling motor battery, it's a group 27 and I have never ran it down where it would not crank my engine. Also I assume your 15hp has a pull rope so if it did you have a back up.
> 
> Not sure if you have a trolling motor but if you did you could kill 2 birds with one stone.


I do not have a TM, I and specifically trying not to use a TM battery because they are so hefty.


----------



## Marshfly

I use an Odyssey 925 as the starting battery for my Yamaha 2stroke 90 so I would assume that you would be more than ok using the 680 which is the next step down.


----------



## cal1320

My AGM battery died at the ramp one morning. Hit the Walmart and bought a $25 mower battery to get me by that day (elec start Yami 15 has no pull rope without disassembly). 275 cca. Weighs 14.8 lbs. Almost 5 years later, it's still in the boat. 
Elec start and trim tabs are no problem.


----------



## ugaflats

> Odyssey 625, weighs in at a stealth 12lbs.  Used for electric start, tilt, bilge


X2 on a Yamaha F25


----------



## Dillusion

The 625 would have been sufficient, but I went with the 680 in case I want to add an automatic bilge later on.

Does anyone know if these can be charged back up with a standard deep cycle charger?


----------



## AfterHours2

I ended up buying a new charger that had the Agm mode along with others. It is still pretty cheap from Walmart. Just remember to allow plenty of time for a trickle slow charge and you will be fine. A standard would work also as long as you do not give it too many amps. Main thing with these batteries, do not use high charge setting and avoid a complete discharge. Follow those steps and you should get 3-5 years maybe more out of it..


----------



## Dillusion

I have this one http://www.westmarine.com/webapp/wcs/stores/servlet/ProductDisplay?productId=29106&catalogId=10001&langId=-1&storeId=11151&storeNum=50523&subdeptNum=50529&classNum=50534#.UKJmZOOe9mg

?


----------



## Guest

I have the original small AGM Dekka battery which starts my motor and runs the navigation lights, cockpit lights and bilge. I have never charged it outside of my outboard.

I also would not buy an auto bilge vs. a manual one.


----------



## AfterHours2

Honestly, it looks like your charger puts out a constant 6 amp charge which would not be considered a "trickle charge." After speaking with a guy at Batts Plus, he highly suggested using either a charger that has an AGM mode or something that would charge very slowly at a low amperage like 2 or at the highest 4 amps. Yours will probably work but in order to get the longest life out of the battery, I would look at Wal Mart. I bought the Schumacher and it was around $40 or less... Better to be safe than sorry and it has all the settings for AGM, deep cycle, etc....


----------



## Dillusion

> Honestly, it looks like your charger puts out a constant 6 amp charge which would not be considered a "trickle charge." After speaking with a guy at Batts Plus, he highly suggested using either a charger that has an AGM mode or something that would charge very slowly at a low amperage like 2 or at the highest 4 amps. Yours will probably work but in order to get the longest life out of the battery, I would look at Wal Mart. I bought the Schumacher and it was around $40 or less... Better to be safe than sorry and it has all the settings for AGM, deep cycle, etc....


This website here lists it as an 'agm' http://dbcmarine.webstorepowered.com/Guest-Portable-Battery-Charger-12-Volt/dp/B000NI38EE


----------



## edmiears

http://www.amazon.com/PERFORMANCE-12-CELL-MOTORCYCLE-BATTERY/dp/B005KLOYHE/ref=sr_1_1?ie=UTF8&qid=1355193242&sr=8-1&keywords=BALLISTIC+PERFORMANCE+LITHIUM+EVO2+12V+12+CELL

I have this and will share some results soon.


----------



## Dillusion

> http://www.amazon.com/PERFORMANCE-12-CELL-MOTORCYCLE-BATTERY/dp/B005KLOYHE/ref=sr_1_1?ie=UTF8&qid=1355193242&sr=8-1&keywords=BALLISTIC+PERFORMANCE+LITHIUM+EVO2+12V+12+CELL
> 
> I have this and will share some results soon.


You get your boat yet?


----------



## Trickyrick

> My AGM battery died at the ramp one morning. Hit the Walmart and bought a $25 mower battery to get me by that day (elec start Yami 15 has no pull rope without disassembly). 275 cca. Weighs 14.8 lbs. Almost 5 years later, it's still in the boat.
> Elec start and trim tabs are no problem.


Same here, Walmart lawn tractor battery, except it was for my 115. Worked great and lasted for 4 or 5 years.


----------



## OneMoreCast

Dillusion said:


> Whats the smallest and lightest (size as in dimensions, and weight) battery that can be used to start an outboard which has electric start? It would be used on a 15HP merc.
> 
> I'm thinking one of those small/half size odyssey batteries? But I dont know what rating would be the smallest. Weight is a concern too...dont want to shove a deep cycle trolling battery back there.


I realize this is old, but I have the same question and I figure battery technology may be a bit different than 10 yers ago. 

I'd like to get rid of my deep cycle trolling motor battery and get something smaller and lighter. The only thing the battery is needed for is starting and tilt/trim on a mercury 25 hp 4 stroke. I've got a small stern and bow light that I almost never use.


----------



## Gogittum

Room is a little limited on my 16 Starcraft tin boat and didn't want a big battery underfoot. Various sites and forums I read up on were conflicting, so used a different thought.

My Suzuki V-Strom 650cc V twin motorcycle calls for a 10 amp battery and it spins that 60 hp motor hard, so I figured it should start a Suzuki 25 hp V twin with no problem. It did, tho' it took a second to get it spinning....but I had added 6 ft of #8 wire to the cables. Then the Suzuki fried and I bought a cheap old Johnson 25 hp 2 smoke to replace it. It had poorly done extensions on the cables, too.

Same problem, so cut the cables back to the original stock Johnson cables and mounted the battery closer to the motor so's they'd reach. Man, it nearly spins that motor off'n the transom. It's just a standard, cheap, no maintenance motorcycle battery.










This makes for a neat, compact installation that's completely out of the way on the back of the seat.


----------



## OneMoreCast

Gogittum said:


> Room is a little limited on my 16 Starcraft tin boat and didn't want a big battery underfoot. Various sites and forums I read up on were conflicting, so used a different thought.
> 
> My Suzuki V-Strom 650cc V twin motorcycle calls for a 10 amp battery and it spins that 60 hp motor hard, so I figured it should start a Suzuki 25 hp V twin with no problem. It did, tho' it took a second to get it spinning....but I had added 6 ft of #8 wire to the cables. Then the Suzuki fried and I bought a cheap old Johnson 25 hp 2 smoke to replace it. It had poorly done extensions on the cables, too.
> 
> Same problem, so cut the cables back to the original stock Johnson cables and mounted the battery closer to the motor so's they'd reach. Man, it nearly spins that motor off'n the transom. It's just a standard, cheap, no maintenance motorcycle battery.
> 
> View attachment 190844
> 
> 
> This makes for a neat, compact installation that's completely out of the way on the back of the seat.


Wow, that install looks great! I'd love to do something like that. What type of battery box is that? I've got two switches on my current one - lights and small pump - so I'd need to find a box with those. Or add them.
So your saying the fist shot didn't work because the wires were too long?


----------



## Gogittum

OneMoreCast said:


> Wow, that install looks great! I'd love to do something like that. What type of battery box is that? I've got two switches on my current one - lights and small pump - so I'd need to find a box with those. Or add them.
> So your saying the fist shot didn't work because the wires were too long?


I think the battery problem on the Suzuki DF25 was that I used 8 gauge wire and the extra 6 ft built up too much resistance. The wires on the Johnson were really a mess, so cut them off. It's only about a 3 ft run now and the stock wires are heavy. No hesitation now - it spins that motor hard.










Battery box is off Amazon - Amazon.com - and was for a smaller battery, like a 4 amp and I couldn't find anything a bit larger - it was all the way up to a Group 24 or nothing, so I cut the back out of it and the 10 amp Mighty Max "just" fit. Squeeze fit. When I tightened the screws down, they clamped that battery in there tightly.










I built a foilding grab bar for the center seat and mounted the chartplotter on a shelf up high, then made a hinged instrument panel for electrical. This is the final stage of proof-of-concept. I have a nice piece of Sandalwood to make the final panel out of.....soon.

I don't like fussing with fuses, so used circuit breakers. The 2 rocker switches on the right are for the bilge pumps and the 5A circuit breakers are to the left of them. Lowest breaker is 3A for the chartplotter. Toggle switch below is master switch for all electrical. Tiny tach upper left; voltmeter lower left. I had to extend the rg174 coax for the TinyTach 4 ft as well, but have done lots of that. so no problem to do it right. Kill switch lanyard hanging from the drink holder.


----------



## OneMoreCast

Gogittum said:


> I think the battery problem on the Suzuki DF25 was that I used 8 gauge wire and the extra 6 ft built up too much resistance. The wires on the Johnson were really a mess, so cut them off. It's only about a 3 ft run now and the stock wires are heavy. No hesitation now - it spins that motor hard.
> 
> View attachment 190871
> 
> 
> Battery box is off Amazon - Amazon.com - and was for a smaller battery, like a 4 amp and I couldn't find anything a bit larger - it was all the way up to a Group 24 or nothing, so I cut the back out of it and the 10 amp Mighty Max "just" fit. Squeeze fit. When I tightened the screws down, they clamped that battery in there tightly.
> 
> View attachment 190872
> 
> 
> I built a foilding grab bar for the center seat and mounted the chartplotter on a shelf up high, then made a hinged instrument panel for electrical. This is the final stage of proof-of-concept. I have a nice piece of Sandalwood to make the final panel out of.....soon.
> 
> I don't like fussing with fuses, so used circuit breakers. The 2 rocker switches on the right are for the bilge pumps and the 5A circuit breakers are to the left of them. Lowest breaker is 3A for the chartplotter. Rocker switch below is master switch for all electrical. Tiny tach upper left; voltmeter lower left. I had to extend the rg174 coax for the TinyTach 4 ft as well, but have done lots of that. so no problem to do it right. Kill switch lanyard hanging from the drink holder.


Great info, thanks. Cool project. What are you mainly fishing for?


----------



## Gogittum

OneMoreCast said:


> Great info, thanks. Cool project. What are you mainly fishing for?


Haha.....if'n I can ever get the damned thing running right, I'd like to go out the Barge Canal and try for Grouper.


----------



## Gogittum

Here's a better pic of the console in action on the Withlacoochee River.










Since then, I've added the 2nd bilge pump and master switch. Started on the new panel yesterday. The grab bar folds down for trailering and covering.


----------



## OneMoreCast

Cool rig and great looking stretch of river!


----------



## Gogittum

Here's the final control panel that I finished up a couple of days ago. 










Wood is a small Sandalwood cutting board, cut to size. I had to remove wood from the back and inlay the breakers because the wood was too thick for the stems. Oscillating saw was a great tool for that. I made the fabric cover and held it on with snaps to protect the wiring from spray and rain.

Both bilge pumps are installed, all wiring is bundled, tied down and complete (wiring is all tinned copper with glue core heat shrink insulated connectors) - the boat is finally done and only working now on getting that balky motor to run.


----------



## OneMoreCast

Gogittum said:


> Here's the final control panel that I finished up a couple of days ago.
> 
> View attachment 191780
> 
> 
> Wood is a small Sandalwood cutting board, cut to size. I had to remove wood from the back and inlay the breakers because the wood was too thick for the stems. Oscillating saw was a great tool for that. I made the fabric cover and held it on with snaps to protect the wiring from spray and rain.
> 
> Both bilge pumps are installed, all wiring is bundled, tied down and complete (wiring is all tinned copper with glue core heat shrink insulated connectors) - the boat is finally done and only working now on getting that balky motor to run.


Cool project now it's time to go catch some fish!


----------

