Low rest voltage on GNB absolyte IIP cells

[Dapdan]

Hi all,

I am brand new to your site. I am not totally new to RE. I have recently acquired some GNB absolyte IIP agm cells ((100A-19). i have charged them up and max cell voltage at full charge (according to CC) was 2.10v. the tech info i have download suggest that it should be max 2.16v. Has anyone other there has any experience or heard anything about these agm's. (apparently they have sat idle for a number of years after delivery from manufacturer and were never installed into the telecom site i got them from, the techs gave them a charge for the first time a few months ago). I have read some where that catalyst caps, and watering the cells may help. anyone got an ideas or comments. your assistance will be gratefully accepted.

sunny, breezy, beautiful barbados.

Dapdan

ps. the link to the article i found online is

http://www.battcon.com/PapersFinal20...008PROOF_7.pdf


I have found some additional info online for the catalyst cap if anyone is interested in them as well

http://www.batteryresearch.com/catalyst_products.htm

GO POWER 1500 24V, 14 KYOCERA TM&GT130, XANTREX C60 & C40, 1280AH HAWKER IND WET CELLS, 900AH GNB ABSOLYTE IIP AGM. RUNNING ENTIRE HSE SINCE SEP 08

[rplarry]

Dapdan
The Absolyte batteries are some of the best batteries you can get. I had a set that were 9 years old when I sold them 3 years ago and they are still working fine for the people I sold them to. The Absolytes are sealed and never need watering. Do not try to open them or you will ruin them. As I remember I had them in a 12v bank and I set my controller go into absorb at 14.2v. (temp compensated) That is 2.36v per cell. Resting voltage on a fully charged Absolyte llp battery is approximately 2.12v per cell. When you charge them, let the amps going into the bank drop to 1% of the capacity of the bank and at that point you can consider them fully charged. For example if you have a bank rated at 1500 amp hours and you start chargeing it, it will take all the amps your charger can deliver, but as the bank reaches full charge your controller will start tapering off the amps going into the bank, when it tapers down to 15 amps (1% in this example) then the batteries are fully charged.
Hope this helps
Larry

[crewzer]

Link to Exide / GNB / Absolyte info: http://industrialenergy.exide.com/su...n&cl=np_brands

HTH,
Jim / crewzer

[Dapdan]

Thanks crewzer,

that is the info i have and have been using to set voltage points, but the charged rest voltage was max 2.1v and min 2.06v. i have read the links that i posted about the IOVR process and using catalyst replacement caps from Philadelphia scientific.

tell me what you think if you are fimilar with their work or have read the link that i sent.

Damani

[BB.]

The paper is very interesting... I always wondered if the AGM's were failing because of loss of water--because of failing catalysts.

The major issue may be the equipment needed to measure the cell's ohmic value so you know how much water to put back in...

If you can "recover" capacity in an AGM for only 1/10 the price of new--does not sound like a bad idea. But the company is dealing with large cells--not sure how much help (replacement caps, tools, ability to measure water loss in a multi-cell battery) one could get on the smaller cells/battery sets we usually see around here.

-Bill

[Dapdan]

Hi BB,

well for me if i could buy 12 of these catalyst caps and install onto my free gnb agms it would work out for me. i found a site that indicates the price was $35 for one cap within one of the links i posted. i read on another forum where i guy opened a vrla 12battery and inserted 20cc of distilled water and it revived the battery the was otherwise not starting his mower and some months onward it was still working ok. It is an area some one should investigate and put a new product out there like how the hydrocap work for wet cells.

Damani


This is another interesting paper from the developers of the same catalyst caps.

http://www.battcon.com/PapersFinal20...rFINAL2003.pdf

Here is another link to a Sealed VRLA Solar Monobloc
http://www.amberjac-projects.co.uk/S...LLYTE20TSG.pdf

http://www.secbattery.com/content/im...12TSG-2006.pdf

[Dapdan]

Hey Larry,

i am glad to see someone else have some real world experience with these type of cells. fyi i set float at 2.23vpc and bulk at 2.36vpc taking in to consideration temp compesation and after two cycles of charge and discharge resting voltage for one cell was 2.05v and the remainder was either 2.10 or 2.09vpc. i was just wondering whether anyone knew of any attempts by others to improve capacity of these vrla. as i have noted in my links i have found some info relating to this (IOVR method) attempt to improve capacity. Have you tried or know of anyone who tried to desulfate these batteries with say a Solar Converters Bd-2 Battery Desulfator and got any positive results?

Damani

[crewzer]

Dapdan,

The VRLA caps are a new one on me...

A long period without recharging and/or voltage differences between cells suggests your batteries may require an "equalizing charge". The old IIP manual says 2.35 V per cell ref 77 F (25 C) for 12 hours.

HTH,
Jim / crewzer

[Dapdan]

Hey all,

I though i would give an update on my progress.

I have made some progress so far.

I have been able to raise the rest voltage of all of the batteries with exception of the one cell that had a very low rest voltage in the beginning. Whereas all of the healthier cells were 2.09/2.10 now those cells are all at 2.13v (10#) and and one is still at 2.09v (this one was always on the low side as well and started at 2.07v.

I have added a total of about 10oz of water to 11 cells and about 18oz to the very low cell. I also equalized them and they all gases profusely (it was not recommended but i was adding water anyway and therefore was not worried about losing water)

Therefore to date the resting voltage of the entire bank is 25.41v (after a rest of 24hr) as opposed to the initial resting voltage of 25.20v so i have had a useful increase of voltage. I put them on load from about 6 pm yesterday and ran the entire house. I checked the voltage the following morning to be 25.04v after 12hrs under load and 2kw of energy used (as measured by my Killameter). I will allow them to cycle on my house for about 4wk and then do the same thing again (add water and equalize) to see if i get another increase in rest voltage. Apparentlly the rest voltage of these cells when new is 2.15-2.17vpc so not bad for 10yr batteries sitting idle until i got them September 08 for free.

I plan to carry out a capacity test but i need to get a clamp on DC ammeter first so I can accurately measure current discharge. I already have the current discharge tables.

Cheers...
Damani

[westbranch]

Hi Dapdan, you have not mentioned if the battery bank was mounted on its side, though not critical it gave my GNB AGM a small boost in output. the electrolyte will not wick all the way to the top of the cell if vertical.
Also a temp sensor is a critical piece especially that you are in the tropics.. I don't see it mentioned.
lastly test cell condition under load to identify any weak cells.

keep us up to date.
thanks
Eric