Using Alarm Batteries In a UPS

upstatemike

Senior Member
Apart from terminal size, does anybody know the difference between an 8Ah security battery from ELK and a an 8Ah UPS replacement battery with the same physical dimensions? There sure is a big cost difference!
 
upstatemike said:
Apart from terminal size, does anybody know the difference between an 8Ah security battery from ELK and a an 8Ah UPS replacement battery with the same physical dimensions? There sure is a big cost difference!
Label and mark-up. ;)
 
May void the UPS Warantee if still in effect or the Protection Guarantee if it has one.
I use third party ones in mine all the time. Same battery from a battery dealer on the web is half the cost of a real APC one. Though the recycling of the dud is with a free UPS tag with the APC.
 
Warranty is long past so that's not an issue. You can drop batteries off at the battery bin at the local dump at no charge so I don't need the recycle exchange.
 
how big can you go . . . are there any major issues with using a automotive battery wired into either of these (ups or alaram panel) . . .

I realize there may be UL and warranty issues, but are there (real) fire hazard or other issues that would cause it to not work or fail in short order . . .

Pete C
 
The danger you run in to going too big is overloading the charging circuit. I think the M1 is rated up to an 18ah battery. I expect you'd have a hard time getting any such information on a typical cheap UPS beyond "it can handle the size battery that it's designed to use". Some larger enterprise sized UPS's can handle more, as some of them are designed to accomodate add-on battery packs.
 
With a UPS, the physical dimensions are the first concern. My Belkin UPS units use a 7Ah battery that is physically identical to the ELK 8Ah unit. Only difference is ELK batteries have .187 inch tabs and UPS batteries use .25 inch tabs.
 
With a UPS, the physical dimensions are the first concern
I was thinking of locating the battery outside of the physical unit and wiring it to the UPS / Security Panel . . .

The danger you run in to going too big is overloading the charging circuit.

it would be easy enough to wire in a charger that can handle the load . . . and/or use a different charger after an extended blackout to bring the battery back to full charge . . .


Pete C
 
pete said:
it would be easy enough to wire in a charger that can handle the load . . . and/or use a different charger after an extended blackout to bring the battery back to full charge . . .
Yes, that would be easy to do, the difficult thing would be predicting what the UPS is going to do when an external charger is essentially wired in parallel to it's internal charger. You only have one set of leads going from the UPS circuit board to the batter, so unless it's obvious and easy to disconnect it's internal charging circuit, you may have issues. If you were wanting to go just a little over the standard size batter, I'd just risk it and see what happens (UPSs are pretty cheap if you catch the right deal). But if you wanted to connect a huge bank of batteries up to a UPS, I'd probably keep the UPS's standard battery intact, y-connect the leads of the battery to the large external bank THROUGH a 120v powered NO relay, with a separate charger for the bank. That way, as soon as power died, all the batteries would be powering the UPS, but as soon as it returned, the bank would be disconnected from the UPS, and the UPS would only be charging it's own battery, while a separate charger took care of the bank.
 
If you put a diode on each leg of the charger and on each leg of the feed to the UPS you should not have an issue. (Need BIG diodes on the UPS side).

At this point though you are just using the UPS as an inverter and transfer switch. If your going to roll your own you probably should ditch the UPS and buy an inverter and relay to eleiminate the unused charging circuitry in the UPS.
 
Don't even think of using an automobile battery. They are designed to deliver a high current for a short period of time (ie starting the car).

If you decide to go with bigger capacity batteries, you need a "deep discharge" type. Think of an electric golf cart, or an electric trolling (fishing) motor.

They are designed to deliver a steady current over a long period of time, perfect for a UPS.
 
I, too, would err on the side of caution and only use the rated battery for the UPS. Adding additional batteries in parallel add current, and if the circuit components aren't designed to handle the additonal current, you could be melting or welding without even trying.

You can find discount battery dealers all over. Shipping is a big cost, so find one local or short shipping distance from your home. I had great success with BatteryWeb.com, which were located in my former town in FL, but now that I'm in Maine, I'll probably look for a closer source. I have a couple UPS that are jsut about in need of battery swaps again.
 
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