UPS and Power Consumption

[BarraCuda™]

I can make .. but noone wants to buy over the project leh

isn't that cheaper to get a small size UPS and extand the battery connection to the external battery, e.g. those car battery ?

The only problem is the small size UPS can't charge the external battery so you will need a external battery charger to charge the external battery.

[BarraCuda™]

Originally Posted by cwloo

isn't that cheaper to get a small size UPS and extand the battery connection to the external battery, e.g. those car battery ?

The only problem is the small size UPS can't charge the external battery so you will need a external battery charger to charge the external battery.

yap .. they cannot be used for such big capacity batteries. Every charger will have its max capacity rating.

Wah. Sounds like a big project. Have you estimated the cost involved?

[BarraCuda™]

Originally Posted by jc85

Wah. Sounds like a big project. Have you estimated the cost involved?

at least $500-700.

I know APC have a cheaper model call ES-500 .. about 500VA, selling for about $69.
Add a car battery (those dry one) about $100++ , and a external charger for the car battery, say $50 ... should be about $200++ ..

Just connect one main pump to the powerbackup should last you a couple of hrs ..

[BarraCuda™]

Originally Posted by cwloo

I know APC have a cheaper model call ES-500 .. about 500VA, selling for about $69.
Add a car battery (those dry one) about $100++ , and a external charger for the car battery, say $50 ... should be about $200++ ..

Just connect one main pump to the powerbackup should last you a couple of hrs ..

Alot of things to consider,

Is the UPS AC output true sinusoidal wave? some UPS have staggered sine waves and maybe damaging to pumps.

Car battery is not suitable .. its meant for short bursts of high ampere usage. Charging will also release hydrogen gas and can cause explosions!. You will need a sealed deep cycle battery, its meant for backup power and can hold more power.

Charger also cannot use normal battery charger as you cannot switch on the charger 24hrs. You will need a float charger where the charger automatically charges the battery when its less than 90%.

hee hee ..
then you will need the APC Smart series .. which are pure sine wave.
Sim Lim sq are selling the 1000VA version which is S$673, which should be enough for 3 hrs if you draw about 50Watts.

Lower capacity model will be cheaper... need to go back office to check the dealer price if you need it.

[BarraCuda™]

Originally Posted by cwloo

hee hee ..
then you will need the APC Smart series .. which are pure sine wave.
Sim Lim sq are selling the 1000VA version which is S$673, which should be enough for 3 hrs if you draw about 50Watts.

Lower capacity model will be cheaper... need to go back office to check the dealer price if you need it.

then its not worth it anymore .. using a 270Ah battery will yield abt 3000VA .. much much more than 1000VA

Bro,

I JUST knew it was too good to be true.

So, in general is the PF of 0.7 a conservative enough figure to work with, or is this limited to most pumps? And is 10% a reasonable power loss for an inverter?

Originally Posted by BarraCuda™

So if you got a 80watts pump with a power factor of 0.7

Another thing is the power inverter .. they are not 100% efficient so they may lose power by 10% or more by converting 12V to 230V. You will also need to factor this in.