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I've got an old UPS for which I bought a new battery. The new battery is different in size (longer). Thus it doesn't fit in the structure.

However, if I keep the new battery vertically, I can manage to squeeze it in. But with it tilted, the contacts are not on top anymore (obviously) :)

My question is, if it's safe to keep the battery in this position. We know for example, car batteries shouldn't be used in different angles because of some liquid in it.

So is this ok or are there any threats/dangers?


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if its acid, DON'T! otherwise, have it your way... – tumchaaditya Jun 19 '12 at 6:44
@tumchaaditya Do UPS batteries today have acid in them? – itsols Jun 19 '12 at 9:49
i am not aware of that.....that is why i posted previous comment. – tumchaaditya Jun 19 '12 at 11:59
What's the manufacturer and model number on the replacemnt battery? VRLA, SLA, AGM are terms for various sealed lead acid batteries. AGM and VRLA typically have the acid absorbed in fiberglass. Older UPS systems may use Gel, but given the failure due to overcharge and gas pockets in the gel, this is old technology being phased out. Manufacturer's spec sheet will tell you what construction is used for this battery. – Fiasco Labs Dec 20 '12 at 23:57
up vote 3 down vote accepted

Every UPS I have can be mounted in a rack (horizontal) or kept on the floor in vertical position. So there's really no difference.

UPS batteries have solid (gel) electrolyte and are not sensible to tilting...

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Gel went out the door as a useless method of containing the electrolyte in most modern UPS systems. Develops gas pockets, early death on overcharge. Proper term is SLA Sealed Lead Acid or VRLA Valve Regulated Lead Acid. The electrolyte is held in a fiberglass mat by capillary attraction and they're recombinant, hydrogen and oxygen combine back to water. – Fiasco Labs Dec 20 '12 at 23:47

Both gel and AGM batteries can be mounted/positioned in any direction. As those are the types of batteries in home UPSes it is save to mount the UPS in any direction you which.

This might not hold for large industrial UPSes as they might use flooded batteries, but those units tend to have the UPS as a separate unit from the battery so it should be of no concern.

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As FiascoLabs notes, UPS batteries use a fibreglass mat to store the acid in the battery. As such, tilting them (or placing them horizontal or vertical) won't effect the battery at all.

I don't know if UPS batteries use a liquid acid to store power (like car batteries) but if it does, there should be warnings plastered all over it about tilting the battery the wrong way.

Otherwise you should be alright

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Current common VRLA battery technology puts the acid in a fiberglass mat. You can bust these batteries open and nothing will leak out. It's why we can send them through UPS without hazardous fees now. Flooded cell is Ancient Technology for a growing portion of the industry. – Fiasco Labs Dec 20 '12 at 23:51
@FiascoLabs - good to hear, I've updated my answer to reflect this. I assume by UPS you mean US Postal Service, as opposed to Uninterruptible Power Supply :-) – Robotnik Dec 21 '12 at 0:10
@Robotnik good one :D But FWIW, UPS is United Parcel Service--they're the guys with the brown trucks and brown uniforms. The United States Postal Service goes by the acronym USPS and wears various shades of blue. ;) – rob Dec 21 '12 at 1:30
Sending UPS by UPS, heh! We sell aircraft batteries. When Concorde introduced their RG-VRLA-AGM batteries we were able to ship them via UPS without Hazmat fees or special packaging. They're sealed with a pressure regulator system and no free acid. The microfiber mat that the acid is contained in has the added advantage of not letting any hydrogen and oxygen escape, holding the gas mix in close proximity til it recombines back into water. The other Manufacturer (Gill) was forced to rethink things, they produced Gel Cells for a while, then figured out their own VRLA tech. Gel Cell isn't as good. – Fiasco Labs Dec 21 '12 at 1:32
@rob - oh, my bad. I'm Australian you see, it's a disability like that :P – Robotnik Dec 21 '12 at 1:48

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