I think I killed my batteries :(

Good Grief

Good Grief

New Member
Mar 26, 2008
314
Lusby, MD
Boat Info
290 Sundancer 1998
Engines
4.3L V-6's w/ Alpha 1 Gen 2 drives
We have a '98 290 Sundancer w/ twin 4.3L's, Alpha 1 Gen 2 O/D's, a kohler generator and pretty much everything else except for a TV and windlass. We purchased the boat (our first) last spring and still have a lot to learn.

I tried to answer my questions using the boat manuals and am still unsure what to do so I'm posting here.

The boat has 3 batteries (Napa-Stowaway 27DCM), all Group 27 (new in August 2005). 2 are in parallel 1 is not.

I think I killed them :smt021 as I failed to check the water level in them until it was too late (i.e. some cells were dry). The boat is kept in the water w/ shore power and battery charger all season.

It was late last season when I discovered the battery condition after not being able to start. I added water, started the boat and we went out for the last cruise of the season. Once the boat was blocked I turned the battery switches off. Went back last week for this seasons prep and when I measured the voltage on the batteries, the battaries in parallel measured 8 volts and the third battery measured 12 volts.

Since then I pulled the parallel batteries and put them on a battery tender. It took a full day each on the charger to get them to fully charged.

In any case, since it would appear I may have to purchase batteries I am trying to determine what the best option is.

I haven't been able to determine how the DC is aligned for house loads. I have two "Cabin" breakers, one on each main DC panel.

My questions are::smt100
1. how do I determine what each battery really does (starts engine, or generator or house power)

2. what type battery should I look for (typical use is anchored for the day w/ radio and refrigerator on although refrigerator not necessary and occasional head use).

3. how can I determine the condition of the battery? If it is holding a charge is that good?

Thanks.

Scott
'98 290 Sundancer
Sweet Emocean
T4.3L, Aplha 1 Gen 2
Lusby, MD
 
Take the batteries to AutoZone for evaluation. They are probably bad. You should replace them all at the same time with the same type (don't mix and match) since they all run off the same charger (otherwise the ones that charge the fastest will cook while the charger continues to charge the others). To determine what does what, take one side out of the circuit at a time and see what still works. If you have battery switches, switch one side on at a time and see what works.

I went with Optima deep cycle batteries and am VERY happy with them.
 
Only replace the ones that are bad. A battery that holds a charge and reads 12 volts does not need to be replaced. Do have them all load tested to determine which, if any are useable.
 
A battery may check good on a load test but still have significantly reduced capacity. When you allow the plates to get dry, they get coated with scale that insulates them so the dry portion may never function again. THe covered part of the plates may pass a lod test but you may still have 1/2 or less of the reserve capacity you once had.

If you change battery types, then change all at thesame time.

With your history.....neglect? hard to get to? didn't know? etc.....you really should take a look at AGM batteries ..absorbed glass mat.....they are dry and never need water, they are completely sealed so there are no corrosive or explosive fumes. I find that even with proper maintenance AGM's last longer by a factor of 2X. Best of all, once you put them in your boat you never have to look at them again until they need replacement.
 
If money is no object, yes, by all means buy all new batteries. Make sure they are the most expensive and longest lasting too.
 
I would not gamble with the batteries that went when out on the water. Simply not worth the few hundred dollars you save by not replacing the batteries.

Frank suggestion of AGM batts like the Optima's is very sound.... one of the best purchases I made for the boat. I got rid of brand new wet cell batteries for Optimas (friend had good use for the messy batteries) No maint (i.e. water, etc) and better yet no mess.... oh and they last twice as long....
 
Jeremy,

You forgot to add that since money is no object he should pick the most expensive batteries he can find.............never mind that they are safer, cleaner, neater, will not corrode anythying positioned nearby, require significantly less maintenance and last at least twice as long.
 
I'm a big optima fan myself... but also check into Sears DieHard PM-1 (blue case, gray top; AGM)... consumer report rated them just above optima... all others with a good distance from the top two. I've used both and the Diehard has better RC and AH ratings for it's given class (although it's not a monumental amount)... and the diehard has a MUCH longer warranty (But I've not experienced Optima's having a short life either so...). I'd just say do some comparisons and go with whichever you like more. You will not go wrong either way.

Anyway, depending on your battery hold-down system... the diehard might drop right in where the optima may not fit so well.
 
To be frank, I didn't know I would need to periodically add water to the batteries, the learning curve is still pretty steep and sometimes I'm so close to the obvious that I can't see it :smt013... The batteries are not difficult to get to, out and in for all 3 is under 15 minutes. The hardest part there is keeping the hold down (J-bolt) from turning out of the capture device at the base.

As far as the batteries go, they both seem to be holding a charge (12.7 volts) I am going to check the specific gravity tomorrow and take them to autozone (Brilliant!) :thumbsup:

Regardless of incomes, money is always an object. I don't want to fix something that isn't broke, but if I have doubts I'll fail safe and get new batteries, not having to call sea-tow is worth that much.

Is the general school of thought that if you have to replace one you should replace them all?

To be totally honest I have looked at so many differnt views I still don't know what I want to or should do. I know I do not want starting batteries. It would appear that the dual purpose battery (marine) is the best option if I stay at the current size.

The batteries I currently have are dual purpose. I read that to move from a dual purpose battery to a deep cycle battery you should move up in battery size to prevent premature failure of the deep cycle battery due to it's limited starting current ability. I think I could move to a group 31 battery no problem as the sizes are still pretty close. Comments?

Thanks for all your help. I'll post the test results tomorrw.
 
If one battery in a bank is bad you need to change both only if you change battery types.

With 4.3L engines, a deep cycle battery works well as a starting battery.

Check the specs on the battery brand you select then decide on group 31 or 27. Typically the larger battery only adds additional capacity and more cranking amps. Not sure you need either with 4.3's and a 290DA, so this one is a $ choice for you to make.

Don't de defensive about the learning curve......some won't admit it, but we all started at the same place, where you are. Its just that for a few of us it was a real long time ago! It is the interchange with other boaters, either in person or on a forum like CSR and technicians, etc. that speed the curve along, so don't be hesitant to ask questions.
 
Thanks, good info.

It was not my intent to come across as defensive, my apologies.

I appreciate the knowledge you are willing to share so I don't have to learn it all the expensive way :smt038

Small change in plans for today so the battery test result post won't be until this evening. Brother and family coming in to town, we're off to see the Cherry Blossoms after 17 years in MD, we're finally goin to take the plunge...
 
fwebster said:
Jeremy,

You forgot to add that since money is no object he should pick the most expensive batteries he can find.............never mind that they are safer, cleaner, neater, will not corrode anythying positioned nearby, require significantly less maintenance and last at least twice as long.
Click to expand...


:)

I personally think the optima's give me the best value. Your experience Frank in the real world big boat environment has shown 2x battery life that in itself makes this battery economical (read: cheaper). The boat is left on the charger 100% of the time when not in use... in my area of the country (dry) I was in the engine compartment every other week with water distilled water and a turkey baster filling the batteries. Finally removing the batteries to clean all of the "stuff" (the stuff that will burn a hole through your shirt) off the top of the batteries and from the tray every so often.... was common place with wet cell batteries. How much is your time worth?

I installed my Optima's and that is the last time I have had anything to do with them. The tray's are as perfectly clean and there is no scent of sulfur anywhere in the engine compartment. There was no downside to this battery swap.

Good luck on your battery work
 
most true dual purpose batteries will have plenty of cranking amps. You would have a problem where you to start looking at getting into strictly deep cycle batteries.
 
hey homer!
dont have a cow, the best lessons learned are the ones that cost you money!
main_simpson.jpg



i THINK your two parallel batteries are house and start one engine. the other battery is solely for starting the other engine and genny (if you have one). it doesnt run any accessories. if you replace, you should replace the parallel ones at the same time, with the same battery. your on-board charger likely has two banks so it will detect that the solitary battery is different. problem with parallel batts is that if ONE is calling for a charge, the charger will send the voltage, even if the other is OK. this cold fry the good battery. thus, the need to change both on that bank at the same time with the same battery. that being said, i bought two STOW-AWAY deep cycle group 31s from sam's club. they fit in the same tray as the two parallel 27s i replaced. this will be my third season with them - despite the myths, they have absolutely NO problem cranking the big block, even after sitting on the hook for 5 hours with the stereo cranking and the fridge on. and they cost $69 each. my single battery is the marine starting variety and is stamped H-1 (aug 2001). i have never had a lick of trouble from it and right now, going into it's 7th full season of service, it has been sitting in my basement since oct 5th and it is still reading 12.46v!!! go figure (it is an EverStart).

if you do wind up replacing the batteries and you are certain you'll keep an eye on the water levels, i cant see the point of spending hundreds more on Optimas. not sure how long they'll last, but, with proper care, the good old fashioned batteries should give you three seasons. if you're lucky, you'll get seven seasons!
 
Last edited:
DOH!

OK, so I had each battery on my battery tender until equlaized and fully charged.

After being off the charger for about a day, one battery stabalized at 12.7 volts, the other at 12.33 volts.

I took both batteries to auto zone where the machine recommended that each be recharged and tested again. That was pretty much all I needed to push me over the edge for new batteries. Can't see myself being out on the water and enjoying it w/ questionable batteries gnawing away at me.

So, off I went, taking into account:
- the knowledge shared here
- what Sea Ray suggests for this boat
- the vast amount of info avaliable from google
- what worked fine in the boat previously (until I ruined them)

I purchased 2 group 27 dual purpose batteries.

I did notice that of the 10 or 12 group 27 batteris there some had manufacturing dates as old as August of 2007, the newest being January 2008 (which I purchased).

Thanks for all your help :smt038

Regards,
Scott
 
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