Refilled batteries not holding charge.

[mestrezat]

I just refilled my 6 six volt Trojan 105s and they seem to loose their charge much faster now that they are topped up with distilled water. It's happened before and after a couple of days of some extra charging, they are back to normal, lasting a good day with out needing recharged. Don't think this is normal but it's been going on for quite some time so I thought I'd toss it out for some feedback. The batteries are almost four years old so while not old, they aren't new either.

[StuM]

Not uncommon if you allow your battery electrolyte to become heavily depleted before you top them up. When you top them up, the distilled water and battery acid will form layers initially. The heavy acid concentration at the bottom and lighter concentration at the top will affect the "open circuit voltage" and make it appear that the battery is fully charged when it is not. It will take a couple of charge cycles to mix them thoroughly. (The technical term is "acid stratification").

The best solution is to monitor them and top them up with smaller amounts of distilled water more frequently. If they do get really low, only add enough water to just cover the plates and fully charge them in that condition. Then top them up once they are fully charged.

[john61ct]

Also make sure really fully charged, then do a "equalizing" cycle as per Trojan's specs.

You should be able to do this manually, watch declining Amps.

Ideally repeat monthly, and try not to let fluid get too low.

[a64pilot]

Th equalizing charge will cause them to gas off some, and when that happens it has a tendency to mix the electrolyte, a little like boiling, except of course it's not boiling, just H2 bubbles coming off the plates

[Wotname]

Originally Posted by a64pilot

Th equalizing charge will cause them to gas off some, and when that happens it has a tendency to mix the electrolyte, a little like boiling, except of course it's not boiling, just H2 bubbles coming off the plates

The H might be boiling being as its boiling point is around -423F but yeah ff topic: (by me, not you)

[mestrezat]

Originally Posted by Wotname

The H might be boiling being as its boiling point is around -423F but yeah ff topic: (by me, not you)

If I was tied up to a marina, I could do the equalization but I'm always out on anchor with a Yamaha 2400 generator and there is no way to run it long enough to do an equalization. Believe me, is love to do it but I just don't think it's possible. At least I know that in a few days at most, I'll be back with the normal usage of my batteries.
If someone knows how to equalize them from a generator and not shore power, I'd love to hear from you. Left the US in 2009 and spend as few days in marinas as I can. If I could do an equalization, should I take the caps off while the cells are bubbling away?
Thanks everyone for your help. This is the site I count on for guidance and assistance.

[john61ct]

Well the time spent equalizing is one issue, but really just getting them to 100% full then putting the high **voltage** on as long as you can will do some good.

Long as they were truly full the day before, no load overnight, then start with a genny charge early morning at 16.2V for one or two hours, doing other things as well is OK, amps are low.

Then a full solar day at the same voltage, should be good enough.

Likely want to isolate from any devices might be harmed by such high voltage.

Do that once a month your bank will last a lot longer.

[mestrezat]

As I said, I''m not at a marina where I could get the batteries up to 100%. Out here on anchor it's impossible unless I ran my charger for hours on end. No solar panels to assist. As for having no load overnight, well that's just not going to happen since I have fridges to run plus anchor lights, etc.
It's why I haven't done an equalize in a long time. If you know a way to do it when out on anchor with just a small generator charging the banks, I'd really love to hear it as I don't have a clue.
Thanks everyone for the input. The generator is running on the stern as I'm typing this message. Figure a couple more throughout the day should do the trick and if not, well there is always tomorrow(God willing).

[witzgall]

There is no magic bullet, you just need to run that genny and charger for a long time. The big downside to lead acid batteries, including AGMS, is that they need to be topped off regularly. If they have been treated poorly (not ever topping off) for a long time, perhaps a few years, you may be looking at batteries that are already at/near the end of their life.

Chris

[rwidman]

"The batteries are almost four years old so while not old, they aren't new either. "


Well, they are old. Four years is a good run. You may get a couple more years out of them, you may not, especially if you let them get fully or mostly discharged once or twice.

[Sailmonkey]

If you've not had a good full charge in four years your batteries are most likely shot.

You can try to equalize, and it will take a while, no two ways about it, and it may help your batteries.....but I'd bet that they're actually ready to put a fork in done.

[Cadence]

Originally Posted by StuM

Not uncommon if you allow your battery electrolyte to become heavily depleted before you top them up. When you top them up, the distilled water and battery acid will form layers initially. The heavy acid concentration at the bottom and lighter concentration at the top will affect the "open circuit voltage" and make it appear that the battery is fully charged when it is not. It will take a couple of charge cycles to mix them thoroughly. (The technical term is "acid stratification").

The best solution is to monitor them and top them up with smaller amounts of distilled water more frequently. If they do get really low, only add enough water to just cover the plates and fully charge them in that condition. Then top them up once they are fully charged.

Oh hell just pick them up and shake them. Couldn't help myself. Your advise was sound.

[mestrezat]

I try and check and top them up the first of each month(sometimes yes and sometimes no)as I've seen what ignoring batteries on other boat can cause. My last set got trashed while we were in the Philippines as their wiring system didn't want to play nice with mine.
We were in Trinidad last year and did have shore power as we were on the hard getting repaired. Everything got a nice full charge as it did in Grenada when we were in a marina avoiding the hurricanes so they do every once in a while get a nice tummy full of volts. With marinas in the US Virgins hitting over $200 a night, I willingly passed on them(duh!).
I finished my second charge of the day a couple of hours ago and they seem to be playing much nicer than they did yesterday. Keeping a charge much longer now. Figure one more day of this and all should be fine again. Batteries run well over $300 a piece here so no matter what, I think it can wait till maybe Panama or Mexico.

[john61ct]

Wow, sorry didn't realize you have no solar?

Why not?

Yes your bank is likely in need of replacement, surprised still limping along after 4 years of PSOC abuse, likely very sulfated.

Not that you'd want to be a pioneer, but have a look for the hybrid LFP bank idea, this would actually be a valid use case.

If you don't get even a small solar setup, don't buy expensive batteries, the cheap 6v golf cart ones are best when you can't avoid murdering them.

[mestrezat]

We wanted to add solar before we left the US but a boat yard at Point Hudson(Sea Marine- now under new management thank God) ate up all our funds. To replace our transmission, well, that was $6200 in labor plus $3500 for a rebuilt transmission. It's a long and painful experience for two newbies but they pretty well cleaned us out by the time they were done. Close to $40,000! We used to have money and then we bought a boat. Now we have a boat and no more money. It's why we haven't traded up on batteries and added solar. Cruising isn't cheap and over nine years on the move had taken its toll. Once we get back to Mexico, it will finish our circumnavigation. Then home and maybe make some money. Heaven knows the bank account could use it. Any kind of extras or upgrades aren't in the future but if you want to know what it's really like out here, just send me an email. Happy to talk.