Different Battery

[Anonymous user]

Hello,

I have a Back-UPS CS 350. I'm currently working on a project that has limited space and would like to know if i can change the size of the battery that is compatible with above mentioned UPS.

DEFAULT BATTTERY: CSB; GP 1272 F2; 12V; 7.2Ah

BATTERY IN QUESTION: YUASA; NP1.2-12: 12V; 1.2Ah

Any help would be greatly appreciated. Thank you.

OverklocK

[TheNotoriousKMP_apc]

Hello,

While YUASA is a brand that's sometimes used for APC products, the VA/hr. is going to throw off your runtime, and probably not even provide the necessary charge for the UPS. I'm sure if KVar is around these boards he can shed more light since it seems he has to have more of a plethora of knowledge of the use of non-APC batteries in APC systems.

[Anonymous user · Accepted solution]

overklock wrote:
Hello,

I have a Back-UPS CS 350. I'm currently working on a project that has limited space and would like to know if i can change the size of the battery that is compatible with above mentioned UPS.

DEFAULT BATTTERY: CSB; GP 1272 F2; 12V; 7.2Ah

BATTERY IN QUESTION: YUASA; NP1.2-12: 12V; 1.2Ah

Any help would be greatly appreciated. Thank you.

OverklocK

The difference is huge. It's probably a bad idea. The UPS itself draws some power under no load while running on battery and that alone is quite a bit of burden for a 1.2Ah battery. Add some load and expect the runtime to be significantly less than simple (1.2/7.2). Battery's capacity is variable depending on relative load unlike a tank of gas.

The UPS is designed with charging current for a 7.2Ah cell in mind, so the charging current maybe excessive and cause a 1.2Ah pack to vent/overheat. Even if it doesn't get this bad, SLA batteries don't like to be fast charged and if the charging current exceeds the permissible current as written on the battery case, don't expect your batteries to live long.

Message was edited by: KVAr

[Anonymous user]

sorry it's been so long since i've logged on but none-the-less, thank you so much for your response KVAr...it's precisely the answer i was looking for...you've saved me from blowing up my dog who loves laying near the apc because of it's warmth, lol...so if that's out of the question, any recomendations you can give me on the smallest APC unit that can still keep a car alarm running, and 120V air pump, a few flourescent 15" tube lights (12V), and a bunch of 5v LED's?

[Anonymous user]

The size would be a matter of how long you want to "keep running"

[Anonymous user]

essentially, it would only need to run about 10min...any more than that would be a bonus-=]

[Anonymous user]

new question

[Anonymous user]

overklock wrote:
new question

It might, it might not. Depends on the characteristic of the battery and your loads.

If we assume your total load is 48W and draws, 4A, a 4Ah battery would be loaded at 4A, which would be represented as "1C rate". If it's a 2Ah battery, it would be 2C rate.

The higher the relative load, the lesser the capacity that can be used. Name plate capacity is rated at 1/20C. So, for a 1.2Ah battery pack, it's 0.06A. At 4A or ~3.5C you wouldn't get anywhere near the rated capacity of 1.2Ah. You'll have to study the characteristics of the battery pack and the actual combined power draw.