What kind of battery should I be using?

[brewern]

Last year, I purchased an older Chaparral run about, with an 80 HP outboard on it. I can get the exact year when I get back home, for now assume mid 80's. I've attached a picture if that helps.

Let me also preface this with the fact I'm still a noob when it comes to boats.

I had a friend give me 2 deep cycle marine batteries. I thought, well, I'll just use one of these on the boat. They are marine, so they should be fine! Well, this weekend, I charged up the battery, and went to the dock. After putting the boat in the water, I turned the key, and there wasn't much cranking power and I couldn't get the motor running. So, we pulled the boat out, went back to camp and charged the battery some more. After about an hour, I hooked up the muffs, turned the key and VROOOM! Woo hoo! We went back to the launch, launched it, turned the key and VROOOM! After cruising around, we beached it for a while while we swam. After about 1.5 hours, I turned the key again, and whir whir whir. It wouldn't start. While we were swimming, I didn't have the radio or anything else on, but either something is draining the battery, or it's not holding a charge.

After futher research, it now makes sense to me I should have two batteries. One for the engine, and one for the accesories.

My question is, what battery should I buy for starting the engine? Should it be a starting battery, or a marine deep cycle? I assume it should be a starting battery. If so, what is the proper battery to use for starting? The accessories can run off of the deep cycle battery. And if it goes dead, who cares!?!

Thanks!
brewern

 

[brewern]

No Title

It's a 1986 BTW.

 

[procraftguy]

Well what year outboard ? If its unregulated charging system u want a maintance battery with 650 plus cranking amps if its regulated charging system any maintance free battery of same cranking amps deep cycles are for trolling motors and rarlly work for cranking

 

[procraftguy]

Also if sure charging system is working well 1 battery is fine unless u have a radio that I like sepperat on my boat I'd rather have no radio then no start and wife loves playing the radio

 

[brewern]

I'm not sure of the motor year, but like I said, the boat is 1986. I assume the motor would be 1985 or 1986. I'll run the serial number tonight and find out for sure.

I'll also start the motor and see if it's producing enough voltage to charge the battery. How will I know if it's regulated or unregulated?

 

[procraftguy]

Look up or rectifier and look at parts diagram or in service manule im not sure when they started using regulaters I'm preety sure urs is not but someone else may know for sure

 

[procraftguy]

Also reason It matters is older unregulated charging systems use battery as regulator and volts can raise as high as 18 volts at wot so sealed doesn't tack to that very well

 

[brewern]

In case it helps anyone, here is a picture of the boat and engine. I'm unable to upload a pic to the forums right now, so here's a link:

http://tinypic.com/r/35885ft/8

 

[wired247]

Dont get a maintenance free or deep cycle. You want a flooded cell battery for that motor. You can use a maintenance free battery IF you install a 20 amp V6 style $40 voltage regulator.