• Home
  • Help
  • Search
  • Login
  • Register
Pages: [1]
Author Topic: UPS for your plug.  (Read 1551 times)
KPexEA
Newbie
*

Karma: 0
Posts: 19


View Profile
« on: February 10, 2010, 01:51:16 PM »

I have my plug connected to a brand new APC550VA battery backup UPS (39.95 from BestBuy.com).

According to the specs of the UPS it will last up to 43 minutes when you have a 15" LCD and a Mac Mini running on it.

I was hoping that since my sheevaplug only draws ~5 watts that it would actually last longer.

Alas, not. At the 45 minute mark it proceeded to shut off. APC tech support is of no help at all.

Does anyone else have their plug connected to a UPS and if so, what brand, and have you tested how long it will run without power?

Thanks
Kevin
Logged

dattaway
Jr. Member
**

Karma: 5
Posts: 91



View Profile WWW
« Reply #1 on: February 10, 2010, 03:46:09 PM »

I have one of those cheap UPS supplies and have a automotive battery in a battery box next to it.  It will last for days...

Unfortunately, APC supplies float the battery voltage high, which requires the water level to be watched every month.  I believe APC does this on purpose, because it causes a battery that should last 15 years to only last 3 years.  Be careful with this setup, since the battery may be at line voltage and can shock or become a fire hazard.  That's why I keep it in a clean battery case.
Logged

lyzby
Newbie
*

Karma: 0
Posts: 48


View Profile
« Reply #2 on: February 10, 2010, 08:42:12 PM »

>I have one of those cheap UPS supplies and have a automotive battery in a battery box next to it.  It will last for days...

Can you explain this setup a little more fully?
Logged

dattaway
Jr. Member
**

Karma: 5
Posts: 91



View Profile WWW
« Reply #3 on: February 10, 2010, 09:19:50 PM »

>I have one of those cheap UPS supplies and have a automotive battery in a battery box next to it.  It will last for days...

Can you explain this setup a little more fully?


Its where I pull the 12 volt battery out of the UPS unit and extend the wires to a bigger battery.  7ah replaced with 70ah.  That's about it!
Logged

lyzby
Newbie
*

Karma: 0
Posts: 48


View Profile
« Reply #4 on: February 11, 2010, 06:01:11 AM »

Ah, ok, thanks.  Not some form of 12 volts direct to a regulator for plug.
Logged

UnaClocker
Full Member
***

Karma: 0
Posts: 131



View Profile WWW
« Reply #5 on: February 11, 2010, 10:15:17 AM »

Yeah, I'd just get a large SLA battery, and a battery float charger, then get a 12v-5v regulator and wire that directly into the Sheeva. Use a 5.1v zener if you're concerned about overvoltage spikes killing the Plug. FAR more efficient than using an inverter to convert 12v to mains voltage, and then through the internal regulator/rectifier.. The only kink in my plans for doing this... Battery charge monitor to shut down the plug and disconnect it from the battery before the battery goes flat, mostly to prevent damaging the battery.
Logged

SheevaPlug - 8gb class 4 SDHC primary drive, 4tb 3.5" media drive, Debian Wheezy, nginx, Samba, Shorewall

Pages: [1]
Print
Jump to: