Replacement battery for UPS

[Power Me Up]

Battery chargers built into UPS units do not have to comply with this requirement because the battery is intended to be enclosed within the equipment and not accessible to touch.

That may be true in general, but as far as I recall, the APC units are designed for the end user to be able to replace the battery - while the unit is still connected to the mains and supplying power to the load. I'd be very surprised if the battery terminals in the APC units weren't well isolated from the mains.

Obviously, the unit isn't going to act as a UPS whilst there are no batteries connected, but it does save having to power down the load to be able to swap out the batteries.

 

[Timothybil]

I am not suggesting that the battery is directly connected across the line voltage input, that would indeed fry the battery as the line supply is both AC and the wrong voltage.
What is entirely possible though is for one side of the battery to be connected to one side of the line supply, the battery would still receive the correct DC charging voltage, but would ALSO be live at line voltage and therefore dangerous to touch.

Battery chargers sold for charging vehicle batteries etc have the output carefully isolated from the line voltage input to avoid danger if the battery or connecting clips be touched in use. This is a legal requirement in all developed countries.
Battery chargers built into UPS units do not have to comply with this requirement because the battery is intended to be enclosed within the equipment and not accessible to touch.

I agree that in cheaper equipment it is entirely possible that one terminal on the battery could be connected to the Chassis GROUND, which in turn would be connected to Earth GROUND through the main panel, and to Earth GROUND directly through the third wire system GROUND pin. Any UPC that does not have a three-wire cord and plug to connect to a GROUNDed outlet is not safe and should not be used. It is the same rational as polarized plugs on lamps, radios, clocks, etc. It helps to ensure that any area where a user may be exposed to live contacts will be touching the ground side of the line, and not the hot.

 

[CuriousOne]

One side of battery is connected to live mains, so always unplug and take care when handling.
In most APC UPS's (at least relatively older models) charging is controlled via LM2577 IC, and since it has short current/overload protection, larger battery won't be a problem when charging, but it should be noted that UPS inverter is might not be rated for longer runtimes, so you have to add additional cooling, or use it at 1/10 power rating or smaller. Personally, I've connected PowerCom BNT-600A UPS to car 12V 65Ah battery, and it works like charm for last 5 years. It should be noted that I'm loading it very lightly - back ups my torrent box and router.

 

[lightseeker2009]

Is it safe to use a car battery indoors? Don't they give off gasses while charging?

 

[CuriousOne]

Mine is located on balcony.

Also, a lot of APC Smart UPS series have "turn off timer", which needed to be turned off via service software.

 

[purduephotog]

When I googled the part number, I found a page of illustrations that included the batteries. It appears it uses four 12v, 8or9Ah batteries in a series parallel arrangement, for a total of 24v & 16/18Ahs, or around 400WH. The UB 1280 battery shown is an AGM SLA with nut and bolt terminals. The next step up to the size you are talking about would be the 35/55 AH batteries, at about $120 + shipping each.

Bahhhhh.

Ebay.

Every 3 years I buy 3 sets of batteries for the UPSs from typically the cheapest vendors (to the US). They've run just fine.

Just a thought- I think I pay about 40$? (can't get to ebay from work)

 

[purduephotog]

Is it safe to use a car battery indoors? Don't they give off gasses while charging?

Yes, they do, and they have to be maintained with water.

Also they have a different charging profile than most batteries in UPS (wet, SLA, AGM). You *can* get away with a deep cycle marine and changing the top off voltage if the unit allows you to, but...

 

[Timothybil]

Bahhhhh.

Ebay.

Every 3 years I buy 3 sets of batteries for the UPSs from typically the cheapest vendors (to the US). They've run just fine.

Just a thought- I think I pay about 40$? (can't get to ebay from work)

If you are buying UPS batteries, you are not buying 35/55AH batteries, either. Even if you could get them for half price, they would still be over $50 each + shipping.

 

[broadgage]

Is it safe to use a car battery indoors? Don't they give off gasses while charging?

Yes, with a bit of common sense it is safe to use a car or similar battery indoors. Provided that significant over charging is avoided by use of a fully automatic battery charger then the amount of gas evolved is harmless in a normal size room except very close to the battery.
It would be well not to smoke or allow a naked flame close to the battery, but in the same room should be fine.

Many disabled people use powered wheelchairs, these are normally used, stored and charged indoors without this being considered dangerous. Until very recently electric wheelchairs used vented lead acid batteries, and some probably still do.
Many domestic garages are used as stores workshops or utility rooms and no one worries about the battery in the car.

 

[NoNotAgain]

IMO, the only time that charging a wet acid battery indoors would present a danger is if you are rapidly charging the battery. Rapid charging generates higher quantities of hydrogen gas. A slow, 1-2 amp charge rate emits minimal gas. Hard charging where you bring the sulfuric acid to a boiling point is where the maximum gas is generated.

 

[Anna Nobles]

Is it safe to use a car battery indoors? Don't they give off gasses while charging?

As long as you use a sealed marine type battery, as opposed to an auto battery, it's fine.

Auto batteries are NOT deep cycle type anyway, each time you fully discharge one, you damage it.

 

[N8N]

FYI most of the time the batteries in these UPS units are standard 12V 7 Ah units with F2 terminals. These are also used in fire alarm NAC panels, emergency lights, etc. So if you have an electrician friend he may be able to get these for you at a discount. If not I would try an electrical supply house rather than Batteries Plus or something like that. The markup on these things is insane.