Free batteries

[mowind]

Hi , a  friend that works at a data storage facility is changing the batteries from their UPS systems and he said that i can have some of the batteries.I don't know how old they are. He will test them and pick out the best ones for me .I would like to know if  they can be used for solar or wind charging purposes. I think i can get about 30 or more.If i take them i will not be using them right away but plan to use them eventually in a 48 v system.How long can i leave them with out charging ? i also have a 24 v battery charger. Can i hook them up to it to keep their charge up ? Below is the link to a webpage with the batteries .

http://dev.powerbattery.com/pdf/1222-2-0805%20PRC-12150C.pdf

Thanks in advance for any advice you can give.

Mowind

[dnix71]

The pdf says they can be left with a full chatge up to 6 months, but I would top them off once month, since they are used.

They are agm, so you need a charger that is designed for sealed batteries. You can't add water.

[Chuck]

I have been using a set of used AGM batteries on my solar system for the past 7 years. Most data center and telecom environments don't stress batteries much (if at all) unless the charger used is improperly matched with the battery or there is really crappy power supplied to the facility.

So far I have had no problems with them. They have withstood temperatures of over 100 deg. F and -20 deg F without noticeable issues other than decreased capacity at low temps (this is normal). I keep them in an unheated barn connected to pv panels using Trace (Xantrex) C type charge controllers.

There are a few things to keep in mind when using these type of batteries. For the longest life span do not drain the batteries and keep the depth of discharge to a minimum. If it's possible to keep them on a (temperature compensated) float charge during storage, do it. They will self discharge, although it takes a while to do so.

Never equalize AGM batteries. Make sure you set your charger to the proper float and bulk charge settings for your specific battery. DO use a temperature sensor and make sure the charger is set to the proper adjustment per degree.

Assuming at some point you actually set these up for use in a solar/wind system, make sure you size your power source to your load so that you can get the batteries back up to full charge as often as possible (every day ?)

[Airstream]

On my 10-year AGM's they call for bulk charge at slightly above normal float ONLY if there is another expected discharge cycle that would drop battery charge levels beyond an optimal point (20-30% Depth of Discharge.

Their complete voltage limited float requires a high charge current of C/4, 25% of listed amp hour rating to use the high current to better mix the thick electrolyte in the glass mats.

[cylindar]

Most AGM types are junk when they are discarded. Yes, you can get some use out of them but don't expect much. They also have to be charged with care and precision and good electronics. Not worth the effort. For second hand batteries stick to flooded lead acid.