Modifying a RCT2000VA UPS with an External charger

[KOPITE]

This is the area where a resistor is missing R109

 

[thehuman]

This is the area where a resistor is missing R109

R109 not needed in this model most probably . Also dont seem like part of the charging circuit

Done some testing on my apc ups
It is using 2 x internal 18ah bateries
Current limited to 5amps
Float voltage of 27.7v
Currently have 24v 100ah bateries conected
Conected an external 3 stage solar charger
Solar is proving 2 amps (nearly no sun)
Ups is providing 5 amps if battery voltage is below 27.7 v
Battery voltage is 27.95v now
Ups is providing 1.2amps
Solar is proving 2 amps

Will report back later when battery voltage is higher

 

[KOPITE]

This in an interesting read for anyone that's interested. Few food tips being mentioned about ventilation and battery type.
http://forums.anandtech.com/showthread.php?t=2026013

Going to phone Victron tomorrow whether the internal charger trickles the batteries and does not damage them at all. I also need a multimeter or voltmeter and find out what it maxes the charging current. I also need to check the battery specs and find out what the correct charging voltage it takes when fully charged. This will determine either under or overcharging.

Last resort is I might sell my ups with external charger for 2K and just buy myself a 1200w Ellies inverter. That to see where I can find one, but i have to get a buyer first before I buy one.

 

[thehuman]

Makro sells ellies inverters

 

[The_Traveller]

Note to KOPITE.

Send the thing here to me. Let me sort out and do the simple mod and check it out. You take internal batteries out and pay postage both ways. Done and dusted. Any work I do on the thing I will share here on MBB. And the labor is free.

We all need to learn here. Plus I have equipment that can monitor and do stuff.

Ball is in your court.

You wouldn't have a twin brother who has these skills, living in the GP area by any chance? need someone to help me do a mainboard swap ...

 

[KOPITE]

You wouldn't have a twin brother who has these skills, living in the GP area by any chance? need someone to help me do a mainboard swap ...

Main board of the rct2000va?

 

[KOPITE]

Makro sells ellies inverters

Can't find one in cpt. Will have a look around.

 

[KOPITE]

Any downside to using a UPS as a charger?

http://www.rcgroups.com/forums/showthread.php?t=1473721

 

[KOPITE]

R109 not needed in this model most probably . Also dont seem like part of the charging circuit

Done some testing on my apc ups
It is using 2 x internal 18ah bateries
Current limited to 5amps
Float voltage of 27.7v
Currently have 24v 100ah bateries conected
Conected an external 3 stage solar charger
Solar is proving 2 amps (nearly no sun)
Ups is providing 5 amps if battery voltage is below 27.7 v
Battery voltage is 27.95v now
Ups is providing 1.2amps
Solar is proving 2 amps

Will report back later when battery voltage is higher

Ok, so battery Float charging Voltage 13.6 to 13.8 VDC/unit Average at 25oC
Meaning 24v system can be between 27.2 and 27.6 when charging is finished and just running on float

http://www.comx-computers.co.za/RCT-2000VAS-Line-Interactive-2000VA-1200W-UPS-Buy-p-86857.php
Full protection - overload, discharge and overcharge protection

 

[thehuman]

This in an interesting read for anyone that's interested. Few food tips being mentioned about ventilation and battery type.
http://forums.anandtech.com/showthread.php?t=2026013

Going to phone Victron tomorrow whether the internal charger trickles the batteries and does not damage them at all. I also need a multimeter or voltmeter and find out what it maxes the charging current. I also need to check the battery specs and find out what the correct charging voltage it takes when fully charged. This will determine either under or overcharging.

Last resort is I might sell my ups with external charger for 2K and just buy myself a 1200w Ellies inverter. That to see where I can find one, but i have to get a buyer first before I buy one.

Getting a multimeter (amp meter + volt meter ) will help you alot

 

[spiff]

Pretty much what I ended up doing was Inverter + battery bank + battery chargers.

I have a cheapo UPS that my sensitive stuff sits on, so they can ride through the transfer.

I auto-failover using these:
http://www.amazon.com/dp/B0078RDYEC/ref=pe_385040_128020140_TE_3p_dp_2
With this:
http://www.amazon.com/dp/B005TALQYU/ref=pe_385040_128020140_TE_3p_dp_1

The relay has a 240v coil. When the power goes out it switches my AC output to the Inverter. Hence I'm switching from Eskom AC to Inverter AC using that relay. Switchover is super quick also. Lights dim slightly nothing more (switching time is slightly more than a cycle which is nothing). It is enough that a PC would shut down tho, hence the UPS to "ride through". UPS cost me R400 or something so don't mind to much having spent that extra.

Since that relay is rated at 16amps (3680watt @ 230v AC), I'm happy with using that instead of a mechanically interlocked contactor which would cost 10x as much. To be clear however, I'm only running my lights and PC from my Inverter. If I went more than that I would need to buy a contractor to switch it safely.

thanks Gnome.

thanks for the links. I have set mine up same as you .

my Eaton 660w UPS carries the dstv / 51' CRT tv and 14w LED light (+-300w) when eskum fails till I can plug the 100Ah battery / inverter mains output into the UPS mains input. I will swap out that relay for a 220vac one and eliminate the manual mains switch over between the UPS & inverter. I don't see any need to draw more than 300w with setup as it's all I need.

what I do need is an isolator for the battery cables as I don't like clamping and un clamping the crocodile clips from the battery terminals every time.

 

[Gnome]

thanks Gnome.

thanks for the links. I have set mine up same as you .

my Eaton 660w UPS carries the dstv / 51' CRT tv and 14w LED light (+-300w) when eskum fails till I can plug the 100Ah battery / inverter mains output into the UPS mains input. I will swap out that relay for a 220vac one and eliminate the manual mains switch over between the UPS & inverter. I don't see any need to draw more than 300w with setup as it's all I need.

what I do need is an isolator for the battery cables as I don't like clamping and un clamping the crocodile clips from the battery terminals every time.

I switch my live, neutral and ground of the inverter in and out (hence the 3 pole relay). Also it is worth noting, my neutral pin on my inverter sits at 0v relative to the earth. Most inverters (especially cheap ones) have the neutral and live pin sitting at a potential of ~110volt. Meaning both wires are "hot" (110v each, out of phase with each other, essential what Americans use as two phase, giving you a total of 230/240v). Our homes are wired for a neutral that is 0v relative to earth and when you have a neutral that is hot it can become dangerous for you as a human. Electronics are perfectly safe to run that way.

They do this because they can then sell the same model world wide.

 

[spiff]

I switch my live, neutral and ground of the inverter in and out (hence the 3 pole relay). Also it is worth noting, my neutral pin on my inverter sits at 0v relative to the earth. Most inverters (especially cheap ones) have the neutral and live pin sitting at a potential of ~110volt. Meaning both wires are live (110v each, out of phase with each other, giving you a total of 230v). Our homes are wired for a neutral that is 0v relative to earth and when you have a neutral that is hot it can become dangerous.

They do this because they can then sell the same model world wide.

great thanks will make sure it's a 3 pole relay

 

[Gnome]

great thanks will make sure it's a 3 pole relay

The one I linked to on Amazon.com is a 3 pole relay double throw btw. I did quite a bit of research and that was the cheapest relay that I could find. If you find something cheaper, drop me a message. So when there is power from Eskom the relay is powered. Therefore my NO (normally open) is wired to Eskom power. My NC (normally closed) is wired to inverter power. Hence consumes no inverter power (although it has virtually no power consumption anyway)

You can also get that relay from RS Electronics but it is more expensive from them. I used postbox courier and got the relay from Amazon.com instead.

 

[KOPITE]

Getting a multimeter (amp meter + volt meter ) will help you alot

Gonna buy one after work. which one must i buy to properly test the batteries or will anyone do.
Zakspeed,Builders or Midas?

 

[spiff]

The one I linked to on Amazon.com is a 3 pole relay double throw btw. I did quite a bit of research and that was the cheapest relay that I could find. If you find something cheaper, drop me a message. So when there is power from Eskom the relay is powered. Therefore my NO (normally open) is wired to Eskom power. My NC (normally closed) is wired to inverter power. Hence consumes no inverter power (although it has virtually no power consumption anyway)

You can also get that relay from RS Electronics but it is more expensive from them. I used postbox courier and got the relay from Amazon.com instead.

thanks Gnome - going to get it via the company works out cheaper for that way - might even have one on the shelf already

 

[KOPITE]

Ok, so have an update on charging current with multimeter. I had the external charger run since Saturday. I took it off and connected the internal charger. Voltage before charging with internal charger was 26.2v . Connected the internal charger and the voltage went up from 26.2 and in the 5 minutes or so it went up to 27.1v and standing idle there. Is this a good sign. How long should I let it charge on the internal charger?

 

[KOPITE]

It's been stable on 27.2v but will still monitor it. Any other tests I can run on the multimeter

 

[thehuman]

Ups charge is a dumb device
It keeps bat at a certain voltage
Next time you get loadsheding and the batteries are discharged meusure the charging current with the multimeter . For this to work need to set meter to current . Move the positive lead to the current connection , disconect one battery pole from battery and put one leed on disconected battery terminal and the other on the loose ups battery lead

 

[KOPITE]

Ups charge is a dumb device
It keeps bat at a certain voltage
Next time you get loadsheding and the batteries are discharged meusure the charging current with the multimeter . For this to work need to set meter to current . Move the positive lead to the current connection , disconect one battery pole from battery and put one leed on disconected battery terminal and the other on the loose ups battery lead

Ok, so what you saying I should stop the internal charger from charging or wait and see when it stops?
Should I only do the test after a loadshed?
So positive on the loose disconnected battery terminal and the negative on the lead that's hanging that was removed?