Problem charging batteries

[gstanton]

?95 Sea Ray 230 Sundancer 5.4 single engine.
Has 2 batteries on a switch (off-1-all-2)
Recently I?ve been having a problem with Bat 1 not having enough charge to turn the starter. About 2 months ago I wire brushed the terminals and sprayed with corrosion stuff as an annual maintenance thing. Lately, #1 will initially grind but then just click. I can turn battery switch to ?all? or ?2? and the engine will turn right over and run fine. Last time out I just left the switch on 2 thinking #1 is bad and I would replace #1 with a newer deep cycle from our travel trailer. Went to the boat to do that and #2 is now dead (as well as #1). Won?t even sound the warning beeper. I went ahead and replaced #1 with the newer TT battery and it fired right up. Ran the boat around for about 15-20 mins to charge ?All?. I noticed then that the voltmeter was barely above the 12 volt position? like maybe 12.5. It normally runs at what is approx 13.5 position. Brought #1 up to the house and put it on the charger and it appears to charge OK. Both boat bats are 1 1/2 yrs. old, in use summer (fresh) and winter (salt). TT bat is 1 month old. All are deep cycle marine.
Suggestions? I only have an old beat up analog (needle) volt/ohm meter ? might be a good chance to get a digital. The question in my mind now is where is the voltage regulator? Actually on the alternator? How to tell if it?s the regulator or the alternator itself? I?m thinking the alt or reg is failing? When I left the boat yesterday I switched the batts to ?off?. Haven?t been back and won?t til Monday.
Don?t think anything is left on, but I have recently installed a Lowrance depth sounder, switched. Also a new FM radio (March) that does have a memory. I would think it would take more than a couple of days to pull a (good) battery down. Am I missing something?
Thanks!

 

[wire2]

Re: Problem charging batteries

There's a problem there somewhere, we need a bit more evidence to point a finger.

At ~1500 rpm, switch on batt 1, check volts of batt 1. Should be ~13.5
Switch to batt 2, take a reading. 13.5? If one of them is only 12 or 12.5 I would suspect the battery.

After standing for 24 hours and not connected together, what's the voltage of both?

Is there a a "green eye" on these batteries? When the starter just clicked was it showing good?

 

[Silvertip]

Re: Problem charging batteries

If the voltmeter is not registering above 12.5 with the engine running you have a bad charging system. You charge them up with shore power and things appear fine until the engine draws down either or both batteries. Since neither of them are charging, it is inevitable they will go dead.

 

[gstanton]

Re: Problem charging batteries

No green eye on any of these bateries.
So when I get the new digital meter in the AM and lets assume I find at the terminals that the voltage input is less than 13.5. Do I replace the voltage regulator or the alt? Where might I look for the regulator?
If replacing the alt, how difficult is it to get the correct tension?

 

[Silvertip]

Re: Problem charging batteries

You don't replace either the alternator or regulator until you've proven either one or the other is bad. Shotgunning a problem gets expensive. Make sure every connection (especially both ends of the battery cables) are clean and tight. I have seen a new battery go bad prematurely so just because they are a 1-1/2 years old, doesn't mean one can't be bad. With the switch in the BOTH position, the bad battery will draw down the good one. So get them load tested. When you have the batteries load tested, take the alternator with you and have it tested as well. If bad, have it rebuilt by your local auto electric shop. You don't need to go to a marine dealer for this. Some alternators have the regulator built into it. Some are separate. I suspect yours is built into the alternator however.

 

[cjames]

Re: Problem charging batteries

Dont get too carried away buying a new multimeter, an old analog one is often times a 'better' meter than a new inexpencive digital. If all you need to do is read voltage, save your money. My $300 Fluke wont read anything with a dead battery, and I rarely think to cary a spare 9V. 9V? nothing uses a 9V anymore....