Checking Smart-UPS ability to charge

[Anonymous user]

Greetings.

I picked up a used Smart-UPS 1500 Tower (SMT1500 - Feb 2011) for next to nothing at a thrift store.  As I expected, the LCD panel indicates that the battery pack is the original and that they need to be replaced.  No power on errors are shown other than to replace the battery.  

To perform a simple test to verify that the UPS is indeed charging, what voltage should I expect to see on a meter at the plug going to the battery with the UPS on and the battery disconnected?  I would like to get a warmer-fuzzier feeling for the UPS health before laying out the money for a new battery.

Thanks in advance.

[BillP]

Hi Stewart,

The charging voltage you should measure on the internal battery connector with the UPS on and the battery disconnected is around 27VDC for the SMT1500.

[Anonymous user]

Hi Szabi,

Thank you for the posting the charging voltage.  Sadly, I see 0 VDC (zero volts) on the battery connector with the battery connected and the UPS turned on.  That would tell me that the UPS is not going to charge the battery.  I'm very glad to know this now before I spent the money on a new battery.

Thanks again for the feedback.

Stewart

[older_apc · Accepted solution]

Hi Stewart

First, check the fuse F900 and R792 on the charger board. 

The module is located on a separate charge behind the battery compartment.

If you have skills in working with electronics, you can turn it on on the table from a laboratory source or sequentially 

through a lamp. The power connector AC J901 pins 1, 3.

DC can measure pins 1 (+ DC) on connector J906; 8 (-Common). 

Check whether the IC900 TNY280GN chip is visually destroyed.

The destruction of resistors R758, R759, R760, R762 is not excluded.

Vladimir