help with a APC ups mod

[yonu]

OK all u have a APC back-ups 350 es with a blown inverter. What I would like to do is repurposed the circuit by removing the 110v inverter and using it as a 12v monitor/ trikle charger for another project. I wanted to see what anyone more knowledgeable with PSUs and UPSs thought of this idea.

Thanks,
Yonu

[Kiriakos GR]

Re: help with a APC ups mod

Its like seeking for trouble.
All the job regarding charging is made automatically by it electronic controller (main chip).
What makes you think that this one survived from been blown too ?

[yonu]

Re: help with a APC ups mod

Well I don't know I do know that according to my voltmeter the battery connections still put out 12v and if I hook abattery to it windows sees the battery so I figured if nothing else I could reuse the monitoring part.

Thanks,
Yonu

[Kiriakos GR]

Re: help with a APC ups mod

I do not wish to discourage you, but is far complex to modify it than repairing the blown inverter.

[yonu]

Re: help with a APC ups mod

OK thanks

[budm]

Re: help with a APC ups mod

So you can hook up the computer to it and you can use APC software to see the AC line voltage and the Batteries info? I sounds like the MOFETs or the drive circuits are damage but not the monitoring circuit are not damage, those circuit is working when the UPS is not in batteries mode any way (inverter section is not need to be running). You have to connected the batteries to it and check the charging current, the low end UPS does not really have complex charging system where it goes through many charging stages.

[yonu]

Re: help with a APC ups mod

Ok please be nice as this is more than likely going to seem very stupid. I have a Idea of how/what I want to do this just not familiar enough with the internals of a ups to sort out what I need to remove or disconnect.

ok I have tested every part of the back-ups 350 es I have setting here and the only thing I can tell is dead is the inverter. now I have no reason for repair/replace the inverter as I don't need it.

What I would like to do is make a new casing and put the unit inline with my 12v battery backup system I have on my low voltage equipment the total load is 3A at 12VDC as I am tired of having to check the batteries. Now I could simply splice in the battery connectors so that it can read the battery voltage and send it to the computer via USB. However my goal is to have it setup so that the load is setup so that the UPS can stay plugged in to 110v for lack of any other way to put it but to act as a giant wall wart unless the power is out then switch to the batteries basically like it works for 110v currently.

Oh and since I know this will be asked part of reason for this is so that I can pass the battery levels over to my Home automation system.

Like I said I more than likely sound like a nut job,
yonu

[budm]

Re: help with a APC ups mod

OK, I see, you want 12VDC UPS (instead of 120VAC UPS) with batteries charger, and monitoring capability through USB interface. I do not believe the charger circuit can put out 3A + Plus charging the batteries at the same time, more likely to have 1A at most.
The model is 350, not something like XX-350?
How is the "12v battery backup system" working right now, just run of the batteries with or without charger?

[yonu]

Re: help with a APC ups mod

I don't have it in front of me right now but I think the model number is BK350R the current setup is 2 deep cycles I charge every couple weeks. I started doing this because 2 of the wall warts caused to much RF in my HAM radios and after 2yrs it has been working fine.

Thanks,
yonu

[budm]

Re: help with a APC ups mod

This one? It is quite new.
https://www.apc.com/products/resourc...base_sku=BK350

[yonu]

Re: help with a APC ups mod

Sorry it is a BE350R I went out and checked

not sure why I thought BK


Thanks,
Yonu

[budm]

Re: help with a APC ups mod

OK, one of those plastic case one.

[yonu]

Re: help with a APC ups mod

You got it.

[yonu]

Re: help with a APC ups mod

Out of curiosity is the 40amp fuse in the charging circuit or the inverter circuit just cant figure out why they used such a large fuse.

Thanks,
yonu

[Kiriakos GR]

Re: help with a APC ups mod

Are you talking about some colored ones ( car Fuse type) ?

[yonu]

Re: help with a APC ups mod

Heap a 40A ATC automotive fuse

[budm]

Re: help with a APC ups mod

Can upload the pictures of the inside of the unit? That fuse is in series with the batteries, to produce 230W (350VA) output from 12V, you need more than 20A (~30A) of current from batteries.

[yonu]

Re: help with a APC ups mod

sure pics will be right up and wasn't sure was just curious about the fuse

[yonu]

Re: help with a APC ups mod

Ok here are the pics of the PCB

[budm]

Re: help with a APC ups mod

Please look at that TO-220 device to get the P/N, I expect it to be xx317 printed on it.