storing a ups

FreeBrrd · August 2009

This isn't solar related, but you guys are the most knowledgeable on electrical stuff so:

I have t o put my UPS into storage for an indefinite amount of time. I was gong to just plug it in and plug a couple little things into it to keep it charged and have a bit of draw on it. I changed storage units & now only have lighting, no outlets so no three wire. UPS will not run on 2 wire. Is the best setup to pull the battery and put it on a battery tender like the motorcycle?

Haven't been on the forum for a bit. I haven't bought my solar for my camper yet. I'm still in my condo. I wont be able to buy to solar until I work, but I can park in the shade or go somewhere cooler if I'm not working. Camper isn't quite done. I stopped working on it for a bit. Just now getting back to it.

BB. · August 2009

Re: storing a ups

FreeBrrd,

Welcome back--missed you!

My experience with wall wart maintenance chargers has been poor... Even a 1 amp unit designed for maintenance charging (actually turns on and off the output based on battery voltage) eventually boiled dry 2x100 AH storage batteries (also--was before "I new better or cared" back around 2000). Used 1 amp maintenance chargers on several cars that don't get driven much but have computers, Lojack, GPS, etc. standby loads. Even a "no water needed" maintenance free battery, still need water every couple of months.

My cheap and dirty solution... Get a "cheap" wall wart" charger and a cheap lamp timer. Set the timer to turn on 1 hour per day (or whatever you think you need). Basically works out to 1 day of charging per month. Should be enough to keep the battery "charged" without overcharging. Has worked very well for me (when I tried the plug in for 1 day a month manual method--I was always forgetting to plug it in, or forgetting to pull the plug).

The other issue--smaller UPS battery sets probably only have a 1-3 year useful life anyway. If the age of the battery and/or the length of storage will exceed that time--it may be better just to pop the battery out and store/dispose (if it corrodes or leaks).

-Bill

FreeBrrd · August 2009

Re: storing a ups

I've had good experience with the battery tender on the motorcycle. The racers recommend them. My motorcycle has been on it for the past year & all is good. Why do you call them "Wall Mart"? As a union carpenter, I don't do any business with WalMart so if it is something they carry, I wouldn't know.

The UPS is a APC BACK-UPS 1200VA 120V - Part Number: BR1200. Not sure how old it is. I can probably ask APC what they recommend. I think they have pretty good customer support.

I do come back & read some posts once in a while.

BB. · August 2009

Re: storing a ups

Actually that was wall Wart (the charger brick plugs into the wall).

-Bill

FreeBrrd · August 2009

Re: storing a ups

oh

( I hate that there is a minimum message length. I'll have to make sure my guest book doesn't have that. at least no 'verification image' I tired to edit that on my guest book, and never found a way that worked. - just babble to make message long enough! )

mike95490 · August 2009

Re: storing a ups

FreeBrrd wrote: »

Why do you call them "Wall Mart"?

Wall WART - a bump on a wall.

FreeBrrd · August 2009

Re: storing a ups

where as "Wall Mart" is an irritating bump elsewhere

I should make the text larger
-old woman!!

n3qik · August 2009

Re: storing a ups

Just leave the UPS plugged in for 24 hrs. That will put a nice charge on them. Pop the face open and slid out and disconnect the battery pack. They are gel-cells, so they should be good for a year.

RCinFLA · August 2009

Re: storing a ups

Battery Tender is actually a three stage charger. Bulks to 14.4vdc, then flips to 13.2 vdc float. If you tie two 100 A-Hr batteries in parallel the 1 amp unit will likely never get out of bulk mode. This will eventually kill the batteries.

Kamala · August 2009

Re: storing a ups

Battery Tenders (brand name) have worked well for me with 12V BCI 31 AGMS (~100AH). The Battery Tender comes in 2 "sizes." The smaller is .75A. I bought 2 of the larger, 1.75A, units for each of my 100AH AGMS. Been working well for 3yrs+. I agree that paralleling batteries to one tender might not work well.

Craig

RandomJoe · August 2009

Re: storing a ups

I thought my Battery Tender (750mA model) would drop to float after a fixed period of time even if it otherwise wouldn't meet the charge criteria. Looking over the instructions for it, I don't see that mentioned and I don't remember where I saw that. -- Okay, I found it. In their FAQ on the batterytender.com website, they mention the "Battery Tender Plus" models differ from the original "Battery Tender" models by holding the absorption phase until the current drops to 0.1A but not exceeding 8 hours. Interestingly, a few paragraphs down they mention both models have a 6 hour "safety timer" - so either way, after 6 or 8 hours the units will drop to float regardless of battery charge state.

At any rate, I hooked it up to my solar system bank (660AH of Trojan T105s) when it was brand new before I had the solar panels installed and it even dropped to float on them. It works great to maintain my 100AH AGM that is currently seeing little use.

A Battery Tender doesn't keep a constant current into the battery while floating. It disconnects completely, waits for the voltage to drop a touch (a couple tenths of a volt or so) then pulses it briefly to bring the voltage back up. Lather rinse repeat. On AGMs, it can be a Very Long Time between the pulses! (I put a WattsUp meter in line with it to watch what it is doing on occasion.)

storing a ups

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