Equivalent Battey (VAH) value as compared with SUA24XLBP battery pack

[Anonymous user]

Hello All,

I am using SmartUPS SUA1500i with network management card 9617 connected to the network. It was running with stock APC 12V 7AH internal batteries which went dry recently.

I have now hooked up two new LEOCH 12V 38AH external batteries to it, using the power connecter extender cable. Have changed the last battery change date in the web interface of UPS. I also have to set the number of the external battery packs to get the correct run time. I have already auto fixed the battery constant using the serial cable.

I came to know that if I attach one OEM APC SUA24XLBP (which are speced at 816 vol-amp-hours) battery pack then I have to mention "1" in the external battery pack field in then web interface.

Now since I have attached non-batteries with a different rating can anyone tell me what is the equivalent value of of vol-amp-hours of the Leoch DJM1238(12V 38AH) battery as compared with the standard APC SUA24XLBP battery pack, based on it I would be able correctly give a value or 1 or 2 in the external battery field, which apparently is the key to optimize the actual backup runtime.

My UPS has a constant load of 30% of the wattage.

Thanks for your input.

[BillP · Accepted solution]

12v 8.5Ah battery ?

generally you would use the standard spec 12v 7.2Ah. most batt manufacturers do have a 8.5-9.0Ah battery, for example HR1234W.

[Anonymous user]

Thanks for the answer.

Whether or not APC does any testing for external batteries is maybe not intended to be known.

I just wanted to know what exactly is the unit definition of Volt-Amp-Hours. If we hookup "1" unit standard APC external SUA24XLBP , then we have to mention "1" in the external battery pack field . The specifications of SUA24XLBP ONLY mention that it is 816 Volt-Amp-Hours battery.

If I am using non OEM batterys I dont know the Volt-Amp-Hours value for it. I do however know that these are 12Volt and 38 Ampere Hour batteries.

If I can convert or form a reference formula for knowing the Volt-Amp-Hours for the non-OEM battery then maybe I can know what is the equivalent size of non OEM batteries when compared to standard SUA24XLBP battery pack.

In this way I can come to more close to accurate value of external battery pack which are to mentioned in the APC web interface and hence can get a more optimized run time.

Hope I am able to make myself more clear now.

Thanks.

[Anonymous user]

I hope it is as simple as a simple multiplication. (which becomes obvious from the unit VAh ).

Since I am not electrically inclined, the search around the internet yielded much detailed and technical definitions of the same.

Taking it to be true if the original battery pack is 812 VAh and custom battery pack is 912 VAh, then the latter is only 1.11 times greater than the former. Which makes sense to enter just 1 in the external battery field. Hope it gives the me the needed backup in the deep dark hours of despair ;-).

Thanks.

[BillP]

hehe!

Your case is a happy one. At least you can change the battery pack counter 🙂

I can't. I have the new LCD model SMX series, and these new units automatically detect externall batteries.
Anyway, what I want to say is that, I did a pack from 2 arrays connected in parallel (one array consists from 4pcs 12V 9.5AH connected in series) so I bassically have 19AH at 48V ( wich is 912 Volt-Amp-Hour), and the orriginal pack, SMX48RMBP2U is 864 Volt-Amp-Hour.
My pack, at 425W load is running 100 minutes (and the SMX48RMBP2U runs 94.1m, at least that's what APC says on the site)
So the point is that, the difference is not that big 5-6 min, nothing to worry about.

Practically I don't know how come that APC externall battery packs are rated at those Volt-Amp-Hour, because basically, to obtain such a value, in my case, a single battery must have exactly 9AH. I didn't find a battery with that specs.
Your case is even more strange, You have 816 Volt-Amp-Hour at 24V, meaning a total of 34AH. So, the possibility to have this value is to build 4 arrays in parallel ( 1 array consists from 2 pcs 12V, 8.5Ah battery in series). So, 12V, 8.5AH battery is not something that you will find in stores 🙂

Cheers!
Adrian.

[Anonymous user]

Well the batteries I am using are Leoch DJM 1238. I have connected two of them in parallel and my Smart UPS 1500 with a load of around 30% is now giving a backup time of around 2 Hr 30m, somewhat close to what I was expecting in case of extended power outage.

Search around you and maybe you can find similar other good brands like PowerSonic and Avon Plus.