12V UPS for Network Rack

[GVolt]

Hi to All,

Goal: Make a UPS system for my Network Rack that will be safe to use for PCs and Network Gear.

Estimated Cost: $1500

Equipment in mind:

• Charger: Victron Energy Blue Smart IP22 12-Volt 30 amp 120VAC, Single Output Battery Charger NEMA 5-15, Bluetooth
• Inverter: Victron Energy Phoenix 1200VA 12-Volt 120V AC Pure Sine Wave Inverter with NEMA GFCI
• Inverter Monitoring: Victron Energy VE.Direct Smart Dongle (Bluetooth)
• Power Distribution: 10 Outlet Horizontal 1U Rack Mount PDU Power Strip - Surge Protection,10 Individual Led Switches，AC 100V-240V-15A.for Network Server Racks, 6 Feet Heavy Power Cord
• Battery: LiTime 12V 200Ah PLUS Lithium LiFePO4 Battery, Built-in 200A BMS, 4000+ Deep Cycles, Max 2560W Power Output, FCC&UL Certificates, 10-Year Lifetime, Perfect for RV, Solar, Marine, Off-Grid, etc.

Idea is to have the 12V Charger plugged in to AC Power 24/7 and have it Configured to float the LiFePO4 Battery and provide Passthrough Power to the Inverter. The Inverter will be On 24/7 Providing Power to the Power Distribution where all the Network Equipment and PC will be plugged in.

Questions:

1. Will this be safe for PC's and Network
2. Will this Kill the Battery because is always receiving a float charge?
3. Open to suggestions.

Notes:
I do not want to buy an off the shelf UPS due to Cost and no way to upgrade it later on for more Capacity.

 

[DIYrich]

Victron inverter is safe for PC and network equipment.

There may be ripple current on the battery, seems to not be an issue.

Get powersupplies that can run the PC and network direct from dc power. Skip the inverter.

 

[GVolt]

Thanks DIYrich, I will have to investigate and learn what ripple current is, I also need to power other non 12v so Inverter will be needed and for the devices that Power supply's are 12v I like the idea of bypassing the inverter

I also came across this Victron Charger/Inverter its more money up front but In the long run I have always wished I went bigger.

Victron Energy MultiPlus-II 120V, 3000VA 24-Volt Pure Sine Wave Inverter and 70 amp Battery Charger

The more I read the more I am now inclined to a 24v system similar setup just combining both charger and inveter, and add a step down converter for 12v devices.

 

[DIYrich]

For a double conversion ups, avoid the all-in-ones. They either charge or discharge, and there is a transfer time if power drops while charging battery.

 

[KevinC_63559]

I just did something similar. I used (2) 100amp LiFePO4 batteries with a Victron Multiplus II 12/3000/120.

By "just", I mean I turned it on about 20 minutes ago <smile>.

Per VE Configure, under a full load I'm pulling about 44 amps from the batteries, for about a 4 hour run time. Of course, could add more batteries to improve on that.

Parts list was simple, bought most of it from Current Connected:

(1) Victron Multiplus II 12/3000/120
(2) 12V 100amp LiFePO4 batteries - bought cheapies via Amazon, but next time will get something with warranty (like CC sells)
(1) MK3-USB cable to allow me to control and monitor the Multiplus II from my PC
(2) 9" battery cables for running the 12Vs in parallel
(2) 3' battery cables for connecting the batteries to the Multiplus II
(2) Blue Sea Terminal Fuse Blocks (connects directly to the battery positive terminals)
(3) Blue Sea 100amp Fuses (one spare)
(1) Surge Protector with 14 gauge wire, 15' - cut to provide input power and output distribution. Should be good for up to 15 amps, but I have current limited to 9.5A via VE Config. I normally only run under 600va total, so plenty of headroom there. I'm configure it lower, but believe 9.5 is the lower limit.

If you don't have one, your going to need something like this to ferrule the AC power lines.

I have some 18 gauge wire on order to make a VSense cable. Not sure if Current Connected makes these, but its trivial to do, especially now that I have the Ferrule kit. Need it to feed my Heathkit GC-1000 12V input as well, so will get double duty from the roll. Really unclear why a VSense cable is needed... the Victron has battery access after all. Seems like they could just jumper internally and be done with it. Oh well.

Unit is silent when running under "shore" power (e.g. the grid), very quiet when providing power from the batteries. Fan is a bit noisy when its doing serious charging and auto-kicks on for cooling. Transitioning back to shore once its restored is delayed by a few seconds (10 perhaps?), which I actually like - prevents transitions during power blinks when the lineman are busy.

Note I limited my charge current to 40 amps via VE Configure. My battery stats suggested 0.2C as a standard charge rate, so, with (2) 100amp batteries that should do the trick. When I first plugged things up, after slightly draining the batteries, the battery BMS showed a max of 36.3 charge amps (on each battery) well within the 0.5C max charge current (which the BMS would have enforced). (Full disclosure: I had shore power limited to 10amps when I first started and that may well have limited charging current to 72.6 amps, maybe. Hmmm, 1200VA in, 72.6*14.6= 1060VA out, perhaps the batteries were just not hungry enough to draw more.)