Battery choice for 135 merc OB 1990 sea ray

[tsennett]

I have done some searches and read some threads - just enough to realize how little I know, so I am resorting to asking a question.
Background - I have a 1990 Sea Ray 180 with a 135 Black Max OB. I don't know how old the battery is, but it doesn't turn the engine over real fast - sort of labors a little and then the engine will turn faster and finally start. I have not had it load tested. The battery sits for one or two weeks at a time - the bilge pump is not on automatic, so there is no draw on the battery (that I know of - if there was I don't think I would have any juice after a week of sitting). The battery behaves the same whether it is turning the engine after a week of sitting, or if I am fresh from an hour of boating (and presumably charging, my gauge seems to indicate the charging system is working.) I have not put any meters on the battery or anything else yet.
My point is that I think I would rather have the peace of mind of a new battery, but I am not sure what to buy. I don't do any trolling, don't sit around with accessories running - I don't even have a radio- so essentially, if anything is turned on, I am underway and engine running.
The boat is new to me this year, but manuals have long disappeared.
I will probably wind up at Bass Pro or Walmart, but before I buy, I thought I would tap the wisdom here for a recommendation on what battery I should get - size, type, etc. Thanks.

 

[Silvertip]

Re: Battery choice for 135 merc OB 1990 sea ray

You are looking for battery information yet you have not proven to us or yourself that you really need one. To prove one way or the other if the battery is an issue, why not try the one out of your car or truck. If the problem goes away you need a battery, and if not, you now know there are other issues. What's not to say the now 10 year old starter isn't drawing too much power, or that the engine has an issue (such as needing a tune-up), or that the battery itself is just not capable of delivering the starting current required (as in the battery is too small for the task), or that there indeed is something causing a slight drain (such as the station memory and clock in the stereo system), or that there is a light being left on to name just a few causes. As for battery choices, you can only go wrong if you buy too small a battery (as in too little CCA capacity). Buy the biggest marine starting battery you have room for with a group size 27 being the smallest I would consider. If you happen to have a farm store in your area start looking there. Then try the discount stores like WalMart. A marine dealer is the last place I would check battery prices only because they will very likely be the most expensive for the same battery you would get at a farm store.

 

[tsennett]

Re: Battery choice for 135 merc OB 1990 sea ray

Thanks for the advice. I have another boat with a 1996 50 hp Force (Merc) and that engine spins fast on starting (I know it is not equivalent) and I was indeed going to try that battery in place of the one on the Sea Ray to see if the problem went away. I had not thought of going to the farm store - there is a Tractor Supply nearby and I will check their prices - I found info from Mercury that says that the minimum battery for the 135 hp OB engine is supposed to be 350 CCA - with 100 min of reserve - so if I get a new battery I will go well above that recommendation -I like the idea of getting the marine battery so that it has the built in terminals that take the ring-eye cable connectors, so I don't have to rely on the add-on terminals for use with a regular automotive starting battery.