APC Smart-UPS RT 5000 XL

APC Smart-UPS 5000

When the batteries in one of these start to fail it spells the beginning of the end for it. When the front panel rips of because someone carried it wrong, that's the final straw.

So what can you expect to get from this? Well, there are some excellent components in here.

Much of the weight is taken up by 4 sealed lead acid batteries at 12V and 17Ah each. Along with that are some incredibly hefty transformers.

But that's just the beginning. The main circuit board is covered in useful through-hole components. Resistors and capacitors of all sizes. Many integrated circuits. What is nice though is the good collection of N-Channel MOSFETs and 24V relays.


Due to the amount of copper on some areas of the main board desoldering can be quite difficult. Some areas were easier to get brutal on and physically dismantle the PCB around the components with cutters. Isolating components from the large ground planes using a sharp knife also helped in places. Some of the ICs are handilly mounted in sockets, but the majority are soldered direct in. These can be somewhat tedious to de-solder, but worth it in the end.


Even though the batteries may have started to die, there is a good chance you can resurrect them. They have probably vented some of their electrolyte over time and just need topping up. Despite their name, sealed lead acid batteries aren't actually sealed. You can find a tutorial on how to overhaul them here.

Interesting ComponentsEdit



  • 24VDC coil, 16A@250VAC/20A@125VAC Contacts


  • CSB 12V 17Ah Sealed Lead Acid