Deka battery uses water fast

Oct 9, 2008
1,739
Bristol 29.9 Dana Point
Basic 1/2/both setup with 2x Group 27 batts. Rotate the switching every few weeks.
The Intersate (Costco) batt doesn't lose much water/acid.
The Deka seems to blast it out, since new.
I've refilled it multiple times while very little required by the Interstate.
Yesterday after neglecting for over a year (oops) I had to put in 1/2 gallon of distilled. Was below the plates. Interstate needed but a few drops.
Why does the Deka burn up water?
Charles 2-bank 3 stage charger. I turn it off when away from the boat. I am at the boat weekly.
 
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Jan 24, 2017
666
Hunter 34 Toms River Nj
not an expert,
Sounds like your charger system is not sensing that the deca batteries are done being charged and is cooking them.
I had a pro nautic charging system that apeared to do the same thing.
Deca Batteries 1 and 2 always need substantially more water then battery 3 eventually cooking 1 & 2. I had always thought that the temp sensor and charging sensors were not working properly. After the first batch of batteries got cooked and numerous letters to the company that I bought the system from they replaced everything under warrantee. So far knock wood no more issues.

I would have the deca batteries tested and make sure that they have not been damaged by allowing the water get below the plates. Your most likely ok if the sides of the batteries are not swollen. Mine had lost almost half the water over the plates and swelled up.

That's why I suspect it's your charger.

Hope this helps
 
Feb 26, 2004
22,759
Catalina 34 224 Maple Bay, BC, Canada
There is [almost] NO charger that "knows when to stop charging based on the batteries..." 99% of chargers are dumb based on time only.

Much info left out of the OP-

charging voltage
battery voltage
resting voltages

Burning water off could be signs of a dead battery. And dried up plates are dertainly signs of that, too.

Many checks to make, systemically, but it sounds like the dried up battery is toast. Check the voltages.
 
Oct 9, 2008
1,739
Bristol 29.9 Dana Point
not an expert,
Sounds like your charger system is not sensing that the deca batteries are done being charged and is cooking them.
I had a pro nautic charging system that apeared to do the same thing.
Deca Batteries 1 and 2 always need substantially more water then battery 3 eventually cooking 1 & 2. I had always thought that the temp sensor and charging sensors were not working properly. After the first batch of batteries got cooked and numerous letters to the company that I bought the system from they replaced everything under warrantee. So far knock wood no more issues.

I would have the deca batteries tested and make sure that they have not been damaged by allowing the water get below the plates. Your most likely ok if the sides of the batteries are not swollen. Mine had lost almost half the water over the plates and swelled up.

That's why I suspect it's your charger.

Hope this helps
Interesting.
The battery is ok as it turned out. Plates were still moist so I must have caught it just in time.
Maybe I'll switch the leads from the charger to see if anything changes.
 
Oct 9, 2008
1,739
Bristol 29.9 Dana Point
There is [almost] NO charger that "knows when to stop charging based on the batteries..." 99% of chargers are dumb based on time only.

Much info left out of the OP-

charging voltage
battery voltage
resting voltages

Burning water off could be signs of a dead battery. And dried up plates are dertainly signs of that, too.

Many checks to make, systemically, but it sounds like the dried up battery is toast. Check the voltages.
the issue has been apparent "since new", therefore a dead battery isn't the problem.
The voltages question is valid. Especially if the Deka side isn't floating. But I checked just now and they're both floating at 13.6.
 
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Jul 23, 2009
857
Beneteau 31 Oceanis Grand Lake, Oklahoma
What is the temperature?
Is the charger temp. compensated? Where is the temp. sensor?

High water usage can be a sign of high temperatures and overcharging.
The design of the venting caps also have an impact on the water usage.

You may try reducing the float voltage 0.2 volts if possible.
 
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dLj

.
Mar 23, 2017
3,372
Belliure 41 Sailing back to the Chesapeake
If you rbatteries have a float voltage on them, then this measurement isn't telling you anything. The voltage needs to be measured after the battery has been sitting for 24 hours without any load or use.

dj
 
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Sep 3, 2013
38
Beneteau 331 Brewer's Warwick
One of them might have been a dud from the start. How do the battery's compare as far how long you can run on battery power?*. Is one of them in a hotter area than the other? In which case you could physically switch locations and determine if it is the battery or the location.

* A simple test which I read about and have tried is to disconnect everything from the charged battery then attach a clamp on inverter to it. Plug a load (such as an electric light) and an electric clock into the inverter and see how long each battery lasts. If you want to measure amp hours just put an amp meter on the battery side. Multiply hours of clock run by the amps. Don't put a bigger load on the inverter than it is rated for. Most inverters will shut down on low voltage so it shouldn't completely discharge the battery.
 
Apr 8, 2010
1,942
Ericson Yachts Olson 34 28400 Portland OR
If the 'bad' battery has been malfunctioning since new, Mr Occam would first take it back for warranty replacement.
( I know a mechanic that always references Occam. My mechanic sez he is just 'lazy' and always looks for the least complicated and least expensive fix...) :)
The idea to change the charge cables from one to the other to rule out (or in) charger problems seems intuitive, as well.
 
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Sep 17, 2012
99
Morgan 383 Fairhaven, NY
Could be a bad cell in the Deka. After a full charge, let rest off charger for 24 hours. Accurately measure voltage to to hundreth volt. Refer to state of charge charts.

I put at least 1/2 gallon of water per (short lake Ontario) season. Had two lead acid 6V golf car batteries as my house batteries. Xantrex Truecharge 20 three stage charger. On shorepower during the week. Checked battery water like oil in the diesel. Every time used. Batts lasted 8 years. FWIW.
 
Oct 9, 2008
1,739
Bristol 29.9 Dana Point
Thanks all.
The batteries are both in the same box side by side. The box is built-in to the interior of the boat. It's at or just below the waterline, so it's cool in there.
The Deka actually delivers more amp hours now than the same-rated Interstate, which I had bought at the same time.
I had replaced a previous Deka with the new one, and had not had this issue with the previous one, so I'm thinking the posters who said it might just be a defective battery may be correct. It's 4 years old now and still running so I'll just keep it full. The previous one lasted 7 years and was still going but I replaced it anyway.
 
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