Questions about my new UPS.

[Barrymore]

The recommended charging rate for most batteries is 0.1C - so for 100Ah, that is 10A.

Are you batteries in parallel? If so, then use the 20A setting to get 10A to each battery. If you batteries are in series (24V) then 10A will be the correct setting.

It was sold as a 24v - 2x100ah batteries unit. I will stick with 10A.

 

[dunkyd]

The recommended charging rate for most batteries is 0.1C - so for 100Ah, that is 10A.

Are you batteries in parallel? If so, then use the 20A setting to get 10A to each battery. If you batteries are in series (24V) then 10A will be the correct setting.

Installed the second battery now in parallel, set the widget to 20A and switched on. Smooth sailing, measuring 14.18 at the terminals. Fan on, green light still flashing. First battery was 13.4 when I connected the two. New battery was 12.95 as carried in from the shop.I presume they will even out in a few hours?

 

[greg_SA]

Are the two batteries identical models? And was the old battery still quite new? Then they will even out...

 

[Bona Botse]

OK PC did not restart at the previous shedding. I saw it was on Wide though so maybe that was the problem.

Bah! PC restarted again =/

Time to get a small UPS just for the stupid server. I see the RCT ones are rated at 10ms max switch over time.

 

[greg_SA]

Interesting - does your serer have a decent PSU? My understanding is that the std ATX sepc allows for a short ~ 20ms loss of power.

The spec says:

3.2.11. Voltage Hold-up Time
The power supply should maintain output regulation per Section 3.2.1 despite a loss of
input power at the low-end nominal range—115 VAC / 47 Hz or 230 VAC / 47 Hz—at
maximum continuous output load as applicable for a minimum of 17 ms.

 

[Bona Botse]

It's a Thermaltake LitePower 350W so I assume it's decent. Even if the power supply allows for ~20ms, it won't help if the UPS keeps hitting its max change over time of 40ms .

Also, it's a server that runs the router OS (amongst others) so when it restarts everyone knows the power just went out due to no Internet, defeating the whole purpose of the UPS...

 

[greg_SA]

It's a Thermaltake LitePower 350W so I assume it's decent. Even if the power supply allows for ~20ms, it won't help if the UPS keeps hitting its max change over time of 40ms .

Also, it's a server that runs the router OS (amongst others) so when it restarts everyone knows the power just went out due to no Internet, defeating the whole purpose of the UPS...

Where did you get that spec of 40ms?

 

[Bona Botse]

Where did you get that spec of 40ms?

From the UPS's manual: "Transfer time: Typical 15-20ms, 40ms max."

At the first shedding the server restarted, then it did not at the second and now it restarted again. Bah!

 

[greg_SA]

Ah, I see... That sucks Luckily mine has a 10ms transfer time.

Maybe a better or over sized PSU might help?

 

[savage]

It's purely just a theory, but you can try a large AC capacitor ("run capacitor" in motor terms, not a "start capacitor") and put that on the AC leads (live & neutral) to your PC. Idea being that the cap will carry the load for the 10 or 20ms that your UPS takes too long to transfer power.

The cap will either blow up and you wasted your money, or it will solve your problem. And no, I take no responsibility for this, I'm just feeling adventurous tonight.

 

[The_Traveller]

I bought my first home UPS from Prostar in 2012, worked like a charm. The transfer time was under 8ms as per the spec sheet said. Not a single component or appliance got affected.

bought my friend the same one in 2014, but the UPS didn't kick in quick enough to keep the pcs and decoders on. Even the lights flickered.

so the supplier troubleshooted and said it's probably the frequency range of the UPS not detecting from AC accordingly . So he sent a new mainboard which looks like DDR RAM, and sorted.

I'm just telling you what I've been told, so if I need to put on a flame suit or anything please give me a heads up....

 

[Bona Botse]

It's purely just a theory, but you can try a large AC capacitor ("run capacitor" in motor terms, not a "start capacitor") and put that on the AC leads (live & neutral) to your PC. Idea being that the cap will carry the load for the 10 or 20ms that your UPS takes too long to transfer power.

The cap will either blow up and you wasted your money, or it will solve your problem. And no, I take no responsibility for this, I'm just feeling adventurous tonight.

I bought my first home UPS from Prostar in 2012, worked like a charm. The transfer time was under 8ms as per the spec sheet said. Not a single component or appliance got affected.

bought my friend the same one in 2014, but the UPS didn't kick in quick enough to keep the pcs and decoders on. Even the lights flickered.

so the supplier troubleshooted and said it's probably the frequency range of the UPS not detecting from AC accordingly . So he sent a new mainboard which looks like DDR RAM, and sorted.

I'm just telling you what I've been told, so if I need to put on a flame suit or anything please give me a heads up....

I'll just go and get a small UPS with ~10ms transfer time since I have no idea what you guys are saying...