UPS Testing 1

[rips042]

Hi,

I purchased a batch of UPS from a liqudation sale recetly. (mainly APC brand). I believe some of the batteries might be dead since the items has been sitting in the warehouse for a while. Is there a general procedure on how to test these units. A lot of these units wouldn't power on when plugged into the outlet. Does that mean the battery is dead? or the unit is completed dead? TIA!

Dave

 

[mdwittler]

Hi there,

I'm in practically the same situation as you!

Except all my UPS's are APC, and I've only got 1 out of 10 to work!

From what I've noticed during my 'experiments' with them - is that they only turn on (with the power plugged in) if they have a GOOD FULLY WORKING BATTERY IN THEM!

So until I manage to aquire some batteries then I can't test the rest.

My question is, IS IT SAFE TO CHARGE A COMPLETELY/ALMOST COMPLETLY FLAT UPS BATTERY WITH A CAR'S 12V BATTERY CHARGER? (If yes then what to I have to check -the Amps?)

We'd really appreciate any help!

Thanks a lot in advance.

 

[toolman18]

Some of the UPS' I messed with you had to hold the power button down a few seconds to power it up.
You really need a user guide. You might have got stuck with a bunch of old units that need the batteries replaced.

Don't waste your time monkeyin' with the 12vdc charger. the batteries are charged W/ 110vac

Ground yourself!

 

[mdwittler]

Thanks for that,

when you say 110vac---how can a 12v 7ah or 17ah battery be charged with such a large current 'alternating current'? <--That question may sound rather dumb ?????! For example I've seen a 12v 'leasure/GEL battery charger' which appeals (to me at least) as sutiable for charging the UPS's sealed lead acid batteries (of which I THINK some brands of battery are GEL batteries). However I DONT want to produce large amounts of hydrogen.......and bang!

Any further info?

Thanks a LOT for the help.

 

[toolman18]

http;//

http://www.pcguide.com/ref/power/ext/ups/parts.htm

Check this out mdwittler maybe it'll help.

 

[netmanrick]

The larger APC units(1400) use lead-acid units. Take a couple of units to your local battery center. Sometimes they will test for free(in hope of a sale).

Rick Harris
SC Dept of Motor Vehicles
Network Operations

 

[mdwittler]

Thanks toolman18 for the link. It was actually a link on that site which has helped me a bit. Firstly though, I don't comprehend why the batteries are charged at 110vac? This is a quote from a website about lead-acid batteries (although not specifically UPS ones).

"Chargers: Most garage and consumer (automotive) type battery chargers are bulk charge only, and have little (if any) voltage regulation. They are fine for a quick boost to low batteries, but not to leave on for long periods. "

Does this mean that a standard 12v charger IS OK?

By the way, the UPS's I'm referring to are a SMART UPS 700 (SU700INET) which is working (i.e. has good batteries). The rest are BACK-UP PRO'S 1400 and have dead batteries (at about 4v currently - seems pretty badly discharged). All I need to do is determine if the UPS's work at all, I don't need to fully re-condition the batteries yet. Incidentally the 1400's have 12v 17ah batteries. The 700 models have 12v 7ah batteries.

Thanks again, I really appreciate the input!

 

[netmanrick]

There is a charger out there that will condition the battery.It rapidly switches input to break the gas bubbles surrounding the electrodes.
Needless to say,it's not cheap. That's why I suggested a battery shop.

Rick Harris
SC Dept of Motor Vehicles
Network Operations

 

[kurttheurer]

I have just done the same with tripp lite ups.

The battery is normally the problem, you can use any 12 volt charger, only ypu have to be carefull with the time you have the battery connected to the charger. The normal battery is 12V 7A, and if the charger is 12V 2A, that means that the battery should be connected 7 / 2 = 3.5 hours.

After the voltage of the batery, with the charger off, should be 13.5 volts. Let the voltimeter connected for a minute or 2 and see if the voltaje drops.

I have to change all of the batteries of the 8 ups I checked.

I put new water with acid to the battery but it didn?t recharged correctly.

 

[mdwittler]

Thanks a lot Kurtheurer, it has been some time since I posted the question and in the absence of a final answer I haven't yet performed any testing on the UPS's - your answer sorts that out!

Just a quick (long) question!- My car battery charger (which I would use to charge the UPS's batteries) says it's 4 AMP, the UPS batteries I need to charge are one with TWO 12v 7Ah batteries and the rest have TWO 12v 17Ah batteries. AS the batteries are connected in parallel do I need to add the two Ah's up of the two batteries and then divide that by the amps of the charger i.e. 4? So that would make it (for the UPS with 17Ah batteries) 2*17=34 then 34 / 4 = 8.5 hours?

Thanks every so much!

 

[kurttheurer]

You should take the batteries out of the ups, first, then you have to be sure how they are connected one to the other. Normally there are two cables that come out from the UPS electronics to the batteries, one black (negative pole) and the other red (positive pole). Parallel: the same cables go to both poles, positive and negative. Serial: the black cable goes to the negative pole of one battery, then a short cable connects both batteries and the red cable goes to the positive pole of the second battery.
If they are connected in parallel, yes you have to add the amps of the two batteries, that is, 28 A, and the totall time to be connected is 28 / 4 = 7 hours aprox.
If they are connected in serial, you have to separated them and charge one at a time or put them in parallel.

 

[mdwittler]

Hi there,

thanks for that. Just wondered how you get 28A? if the two batteries are 17Ah, then you 'add' them as you say 17+17= 34A not 28A ?

Anyway that more or less sorts out my question- many thanks for your assistance.