Did I kill my house bank? Electrolyte was low.

[Mike Banks]

I would hazard a guess here--maybe it was a boat in the US Submarine service--buggered it I can remember the name though. Some Roman god I think?

Anyway--thanks for your service gentlemen. So greatly appreciated--

[Popcorn]

Thanks
I love to sail. When I see the sky, water and stars, I really appreciate having to do so. If I had to do it all over again, I would in a heart beat. Stressful and dangerous yes, but what isn't.

[CassidyNZ]

Originally Posted by Adelie

Kill them? Probably not.
Shorten their life some? Probably.

Put some water in them and cycle them normally for 10 or so cycle. Equalize. Then do a capacity test.

Due to my proximity to my boat at one point I was unable to visit the boat for protracted periods. I twice went to the boat to find the tops of the plates on my Trojan T105s fully exposed and dry. Both times I topped up the electrolyte with demineralised water and charged the batteries.

What I found after was that they consumed water faster after each time and had to be serviced more regularly. But they still successfully did ten years before I replaced them

[Apollo366]

Originally Posted by Popcorn

Apollo, what was the name of your sub. Blenny and Sailfish here.

I was actually on 4 different subs in my brief 7 yr Navy time. Two diesel electric boats and two Nuc powered boats.

The two diesel boast were in Pearl Harbor, HI, I was just an ordinary non-rated sailor then, DBF!
Got to be on the sinking crew of the WWII Barbero, great fun going out to sea for 2 months while the Nuc boat tried to sink her with the newest electric torpedo. They finally sank her with WWII Mk 14 torpedoes after the "New" electric ones only damaged her.

Those boats had over 100 "cells" in each battery (2) and as I said were lovingly cared for.

After Nuc school I was on Scorpion & Shark in Norfolk VA as an electrical system operator. They only had one battery as emergency backup power.

Blenny was a Guppy conversion, right? Sailfish was??

Had a great time in the Canoe Club, hope you did too.

Capt Wayne

[BillKny]

So now we have established that according to the internet wizards the answer is YES or NO or MAYBE.

I'd suggest that you do your own research.

I bet you'll come to the conclusion your batteries are toast, but my opinion is worth what you paid for it.

Or you can just pick the answer you like.

[Popcorn]

Yes, it was converted to, 'Guppy'.
The Sailfish was part of Squadron 8, in Groton Conn. and went to Hawaii for several years, only to return to the PNW, Washington, I think Bremerton at first, then used for target practice and sunk off the coast of Washington also. the Sailfish was built at the time of the Nautilus but financial constrains made it a diesel boat. I didn't mind that, the nuc's were still having their operational problems and the diesels made ports more often. Usually break downs, but engineering I think made it happen more often than one could imagine, lol.
I had a couple of my years on subs and also with the SeaBee 17 group on the west coast afterwards. Also 7 years total like you.
I was assigned to de-commission a group of three subs in Philadelphia, the Blenny, Tench and a third, in which I completed my tour there, and went home.
Yes, I did have a wonderful time, we knew how to party for sure. Great talking to you.

[MarkSF]

Originally Posted by BillKny

So now we have established that according to the internet wizards the answer is YES or NO or MAYBE.

I'd suggest that you do your own research.

I bet you'll come to the conclusion your batteries are toast, but my opinion is worth what you paid for it.

Or you can just pick the answer you like.

Thanks for the replies everyone. At 6 years old, there wouldn't be much life remaining, even if I could get them working again.

However, I would like to understand what the failure mode is. What is it that is wrong with the batteries, internally, now?

I've had batteries suffer the same failure mode in the past : in absorption mode, the current does not drop, leading to overheating and outgassing.

I don't believe it is the charger - that is doing its job, holding absorption mode voltage at 14.8V. The current should be dropping, but it is not.

Maybe micro internal shorts due to grid deterioration? I have read that grid corrosion and ultimate failure is behind 60-70% of battery failures.

The charger is a Pro Nautic 1220P. I went for the remote which is in the cabin, very handy as that's how I noticed the higher current.

[boatpoker]

Originally Posted by MarkSF

Thanks for the replies everyone. At 6 years old, there wouldn't be much life remaining, even if I could get them working again.

However, I would like to understand what the failure mode is. What is it that is wrong with the batteries, internally, now?

I've had batteries suffer the same failure mode in the past : in absorption mode, the current does not drop, leading to overheating and outgassing.

I don't believe it is the charger - that is doing its job, holding absorption mode voltage at 14.8V. The current should be dropping, but it is not.

Maybe micro internal shorts due to grid deterioration? I have read that grid corrosion and ultimate failure is behind 60-70% of battery failures.

Excess sulfation on the plates and internal shorting.
Excess sulfation will happen with age but will occur faster with repeated episodes of low electrolyte
Electrolyte should be checked weekly (friday afternoon is my day for seacock excercise and electrolyte checks among other things)

[MarkSF]

Thanks, yes sounds like it.

I looked at the instructions for my charger. There are two programs for flooded :

1) Absorption 14.8, float 13.6V.
2) Absorption 14.7, float 13.4V.

I am wondering if switching to program 2 would be a little easier on the batteries.

[Mike Banks]

The electrolyte level drops because of electrolysis of the water. Some gassing during charging always occurs--so electrolyte levels must be kept topped up. Some modern batteries have catalytic recombination, so the the oxygen and hydrogen gasses produced are recombined and trickle back as water into the cells. Not all batteries have this.

As the electrolyte level falls, the acid becomes more concentrated--and the internal resistance of the battery changes--allowing even more current to flow.

That is why charging current is not a great indicator of battery condition. Use a hydrometer to test the specific gravity of the electrolyte, and keep electrolyte levels topped up. One reason for having GOOD UNOBSTRUCTED ACCESS (no italics) to the battery banks.


And--I do think that a charging voltage of 14.8 volts seems too high. More than I have ever used on a charging system. BUT--I have sometimes used much higher voltages with a tiny current to equalize cells--maybe once a month or so. The unregulated output from a solar panel for instance--for one day's sunlight.

[Popcorn]

Hi Capt Wayne, I hope you got the latest thread I sent.
You were on the Scorpion, and it did bite the dust in 1968, just before I signed up.
They had a new, although not tested thoroughly, type of hull and shape. That was never again used and the new safety program started just after the Thresher for 'Safesub' construction. Lucky for you, you didn't go on that test.
Nicholas

[Fuss]

You killed the top bit that ran dry but the covered part is still ok. You can work out how much capacity you lost.

[Pete7]

Originally Posted by MarkSF

Thanks, yes sounds like it.

I looked at the instructions for my charger. There are two programs for flooded :

1) Absorption 14.8, float 13.6V.
2) Absorption 14.7, float 13.4V.

I am wondering if switching to program 2 would be a little easier on the batteries.

I have the Trojan TMX24 equivalent (unless I am mistaken then do correct me) batteries which are now 2 years old. I have also dropped the charge voltage on both the MPPT and the mains Sterling 40A Digital battery charger. The main reason was during the winter we don't use the boat as much but the batteries sit fully charged from the solar.

Pete

[MarkSF]

Interesting, what voltages did you lower to?

[Pete7]

Ha, if I could get to the boat I could tell you

The Sterling mains charger was dropped to AGM settings I think, as that is just a quick change of the dip switches.

The Victron MPPT was lowered on the voltage by a bit so that even with the cold temperature the battery sense widget doesn't take the voltage above 14.8v. Same with the float charge, also lowered.

They have been as high as 15.1v in cold weather but since I am not on board much at the moment, a lower voltage was a bit safer and less likely to need watering as often.

I will bump the MPPT back up in the Spring homefully.

Pete