Battery to Start 69 Evinrude 25903B 25HP

[Colorado4Wheeler]

In the past I've used a motorcycle battery, I'm wondering if there's a closed cell battery that will effectively start this. Also, right now, I have a really crummy way of starting it in that I have two large gauge + and - leads from the engine, I clamp the negative onto the battery and then touch the positive to the + side to start it and I would like to do this much better. I think I probably need to get a starter relay so I can run 12v to the relay and use an ignition key to actually crank it instead of this terrible way of starting it up - am I on the right track there?

 

[oldboat1]

Yes. Right track. Be sure to get an outboard solenoid.

You can probably rig a simple harness -- push button start is the easiest.

 

[Colorado4Wheeler]

oldboat1 Thank you! Any suggestions on the battery? I got a small battery box for a trolling motor that's enclosed and I was thinking of mounting my key (or push button) system on that but am not sure what battery to get. I could go the motorcycle route again but then dealing with acid and all that jazz.

 

[ondarvr]

Just match it up with the battery the currently works for you, or upsize if you want, most will cost more, sometimes shockingly more, than what you use now.

 

[Colorado4Wheeler]

ondarvr thank you for responding. My question is I'm not sure which battery to get because how many cranking amps do I need to start a small 25hp outboard like this? I'm thinking a trolling motor battery won't work because it doesn't have cranking amps.

 

[ondarvr]

The motor cycle battery worked, so just about any battery will, a deep cycle trolling motor battery will work fine, but if all you're doing I starting it, then get a starting battery.