When is my sulphated battery charged?

[jelloir]

Firstly, Hullo to everyone as this is my first post

I recently built my first SSG in the form of a Ihmotep/Bedini fan. After hours spent getting it working and then dancing around the room when I finally did... I am now rejuvenating an old UPS battery as part of my learning.

However I am not sure when to stop charging it. Currently it has been charging for about 1 hour and is fluctuating between 11.8ish to 12.7 volts which if I understand correctly is the battery being de-sulphated.

So what level should I let it reach before stopping it? Will it be damaged if I leave it on there overnight?

Lastly, thanks so much for all the information and videos made available online by everyone with and interest in the Bedini Energizer as it helped me get started. I bought the Bedini SG books and I'm looking forward to building a bike wheel in the near future.

Regards,

James

[Yaro1776]

Welcome to the forum James,

Not explicit as to the size of the old UPS battery - assume that it is 12 volt 7.0 amp hr type. Normal charging voltage within a UPS system will probably take it to the 14.6 volt threshold when it is discharged. The Energizer chargers will go much higher than that voltage using a different type of charging technology, always assuming a battery without dead cells. John Bedini has available the "Battery Bible" on one of his sites - this gives you the down and dirty information on LAB batteries, most excellent.

I am unfamiliar with the Imhotep fan charger so cannot advise on the length of time that it will take to bring back that UPS battery. Be conservative!

Enjoy the adventure!

Yaro

[bigmotherwhale]

I charge my batteries to about 15 - 15.3v the are the flooded type however, i think the gel batteries and agm have to go up higher, but best to check.
the first time i charge broken batteries they go up very high sometimes into the 40v range and then quickly drop down all the way to a voltage lower than when i started, then they will slowly climb back up sometimes this takes ages and ages to do,
once you get up to around the 15volt point once or twice the batteries start to hold charge and they will start to charge much quicker and recover capacity, if they don't respond check if they have any acid and water in them carefully, they should not make a rattle, i think there are a few YouTube vids on this

[John_Koorn]

You shouldn't charge any higher than 14.8v for a gel-cell. If you do you will boil them dry and then they are only good as a door stop.

John K.

[jelloir]

The batteries are LONG WP1236W's 12V 8AH. When I was charging from the energizer, the volts were all over the place ranging from 11v to 17v. The fluctuation continued like that, except they did appear to start steadying around 14.5V-15V after a while but would still fluctuate up and down. Once I read John's response I stopped in case I was about to make them worse. They have been sitting disconnected on my desk for a few hours now, one is 3.30V, the other 3.50V even after all the time they spent on the energizer.

I had previously tested the energizer using some brand new 12v 1.3AH gel cell batteries I bought for the project (and was using to charge the UPS batteries) and those seemed fine. I am currently using one of these little batteries to charge an old NiCd 18V drill battery that could not hold any charge, it just reached 18V as I type this, it started at about 13.8V I think (I really need to start noting this stuff down), so the energizer seems to be working well.

Do you reckon the UPS batteries are stuffed? I am happy to keep cracking at them even if it's time consuming but obviously don't want to make things worse.

Incidentally what about this NiCd, is there a voltage I should stop at with that?

I think I might also buy Peter Lindemann's Battery Secrets book, after having a look over John Bedini's Battery Bible.

Thanks for the responses, so far this has been one of the most fascinating things I have ever done!

[jelloir]

One more question... I have a variable resistor so should I simply try to adjust this to keep it below 14.8V when charging the UPS batteries?

[John_Koorn]

jelloir, yes your batteries are stuffed if they are resting at 3v. If you shake them they will probably rattle, indicating that they have dried out inside.

John K.