UPS switches off way before battery is empty

[soulie]

There is an ic which is not adjustable, which controls the cut off time, on most ups products, not all though. Be careful with external battery add ons, minimal load only, otherwise the transformer can overheat and blow permanently

yes ,they dont usually use torroidals ,too expensive ,and the windings cook all the insulation off on the 12 volt to 220 volt side

 

[SauRoNZA]

These things are not meant to keep devices on, they are there to safely turn them off when grid power is lost.

The lead acid batteries will be dead after a handful of full use cycles beyond 50% as well.

 

[ld13]

There is an ic which is not adjustable, which controls the cut off time, on most ups products, not all though. Be careful with external battery add ons, minimal load only, otherwise the transformer can overheat and blow permanently

Been running fine for just shy of 3 years. Load is <200W of the 360W capacity, but I did add an external fan that runs 24/7 to move extra air.

 

[wingnut771]

Been running fine for just shy of 3 years. Load is <200W of the 360W capacity, but I did add an external fan that runs 24/7 to move extra air.

For how long?

 

[deanda]

There is an ic which is not adjustable, which controls the cut off time, on most ups products, not all though. Be careful with external battery add ons, minimal load only, otherwise the transformer can overheat and blow permanently

Yes it's R15 or R20 its a resistor I just watch a video now it's controls the timer

 

[deanda]

 

[deanda]

This is happening to me at the moment. Multiple RPC UPSs die at exactly the 2hr mark. The batteries are still reporting to have ample charge, so something else must be happening.

Is it possible that other zones going off at the next loadshedding cycle cause a brief surge, kicking the UPSs back to pass through mode before killing them? I find it so bizarre that multiple die simultaneously! Unless of course there is a timer. Perhaps I should switch one on at the 1hr mark and see what happens to it

There's a resistor doing this R20 in some ups and R15 in some ups

 

[leon.davibe]

If disabling such protections i would say installing a fan is a must

We have to realise the designs only had to be good enough to deal with the time a lead acid would last

Stretching this time with lithium may drive up the heat

plus either find a quiet fan that runs all the time, or make the fan switch on auto