Really Dead Battery

eddiezuskin

New Member
Oct 6, 2006
141
Chesapeake Bay
Boat Info
1987 250DA
Engines
5.7L Alpha 1
My starting battery was totally dead today as a result of the kids leaving on the aft cabin light and me forgetting to turn the battery switch off 2 weeks ago.

I started with the house battery and took a 30 minute cruise to charge the dead starting battery. No improvement after charging, still under 10volts, I even checked the battery when alternator was charging, 13.5volts. This was a new battery in April of this year. Got it replaced free under warranty.

Is this common to trash a starting battery after only one full discharge.

Eddie
 
I don't think you will be able to bring the battery up to full charge by just using the engine alternator. You need to use a battery charger. Make sure the battery has water in it and as long as this is a newer deep cycle battery, it should recharge OK that way.
 
No battery likes to be fully discharged and left there, especially stating batteries. Peace of mind for reliable starts would merit a replacement or, at the very least, a thorough, multi-stage charge and then a load test.
 
It is not a deep cycle. I took it back to Boaters World and they replaced it under warranty. If it was out of warranty I probably would have tried to give it a thorough charge using the 3 stage charger on shore power.
Eddie
 
eddiezuskin said:
It is not a deep cycle. I took it back to Boaters World and they replaced it under warranty. If it was out of warranty I probably would have tried to give it a thorough charge using the 3 stage charger on shore power.
Eddie
Well that's not too bad but I bet you won't do that again....and I'm sure your kids know too.
With twin 5year olds I relate.
 
Stuff happens! We did a similar thing. Got to the marina and couldn't start the boat! Drug the vehicle battery out and jump started it. Still had problems so we disconnect and rearranged the batteries. Got it running, but when I switched from "1" to "2" the engine would die. Ran fine on "1" and "both" but I couldn't figure out what was going on. Then I noticed the battery was really hot. I had wired it BACKWARDS! DOH! Swapped it and the engine would now run when switching to charge it. I was just surprised I didn't blow a fuse, torch an alternator or some other circuit in the process. Anyway, the same battery is still providing service two months later, but I think a replacement will occur if we keep the boat! We'll probably move the good battery to the travel trailer and replace both next season. Of course, we may upgrade in the meantime!! We'll see! :grin:
 
Big Whooops!

Sundancer, if you reverse poled one of two batteries on a switch and then put both batteries main switches in the BOTH position, you created a 24V battery. Some things really don't like voatage above a defined level. All manne rof truble can be lurking under your hood.

Really need to check out your electronics etc as well.

The converter , ah hell who knows!

Just curious ... what did you think when you were jamming the small battery clamp onto that big post?
 
As Pirate says, starting batteries don't like to be discharged at all. Most likely you sulfated the battery. You can read about that here.

The high voltage charging that the link above mentions is what Dave S. was talking about. Of course, getting a free new one is the best if you can do it is, as you did.

A week is a long time for any battery to be fully discharged. I did accidentally discharge half my house battery bank of golf cart batteries for less than a day. I don't see any signs of ill effects on them, but I have not done a load test to know exactly.
 
Re: Big Whooops!

Asureyez said:
Sundancer, if you reverse poled one of two batteries on a switch and then put both batteries main switches in the BOTH position, you created a 24V battery. Some things really don't like voltage above a defined level. All manner of trouble can be lurking under your hood.
I think when you hook two 12V batteries in parallel, which the switch does in BOTH, then if you have one of them with the wrong polarity, you get close to a zero volt battery, possibly a very large amount of current flowing in a tight loop between the batteries, lots of heat, and the possibility of a battery explosion. I don't see any way you can parallel two 12V batteries and get 24V.

Putting reverse polarity on some electronics might kill them, but I would expect most good stuff to be reverse polarity protected.

The biggest problem I see here is that when you connect two batteries in parallel and one is backwards, one can blow up in your face. My wife, working as a nurse in an opthamologist's office, has had to deal with a person who did that trying to jump start a car. She won't ever help jump start a car again.
 
I was definitely lucky. As soon as I figured out what was wrong, we switched it to the off position quickly! It was only in that position for a few seconds each time, but I realize I was lucky physically and that I didn't have to fix it with a credit card. Last year I put water in a battery and AFTER I did it discovered it was the distilled water with salt added for a pet crab! That generates a nice and deadly chlorine gas that could have killed me as well! That bottled is now labeled as such. Secretly, I've been wondering why these things keep happening and why my wife insists on upping my life insurance! :smt017

As far as wiring the battery goes, all fit on with ring terminals and a wing nut, so there was no big post/little post to deal with. There is always a first time and let's hope LAST time I make that mistake. I think Dave M. is right, it was generating a lot of heat. The terminal was extremely hot for the few seconds (Probably longer than I think!) they were switched to both. As I mentioned previously, everything seems fine now. Everything works!
 
Re: Big Whooops!

Sundancer, if you reverse poled one of two batteries on a switch and then put both batteries main switches in the BOTH position, you created a 24V battery.

Just curious ... what did you think when you were jamming the small battery clamp onto that big post?

Only connecting two 12V batteries in series will give you 24 volts...and connecting them the right way. :)

On the batteries I have, one has the studs for ring terminals, both of the same size. The other has both studs for ring terminals and car-type top-post style, again both of same size...
 

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