You’re almost finished with an AP-on-a-stick site survey and your battery dies! Or, you have a UPS powering the AP and you cannot find a close electric socket to recharge the UPS. Or you have an AP model that requires PoE+ and your power supply just cannot provide the “juice” it needs for these newer APs! Welcome to the ever-changing world of Wi-Fi site surveys.
However, there are new tools out there to help the WLAN professional and one of them is the VenVolt MK1 by Ventev (a.k.a. “orange juice”). It is sleek looking, light weight and the company says it will power an AP for over seven hours. Gcatewifi was asked by Ventev to review this AP site survey power source, so whada ya say we pop the hood on this baby and take it for a test drive?
Opening the Box
When my VenVolt arrived, of course I dropped everything to open the box and check it out. It comes with a recharging wall wart and although Ventev says to recharge it for at least five hours, I saw it was up to 100% charge in a little over two hours. Still, I let it charge overnight before testing it further.
Plugs, Switches, Features
A little more on the details: The VenVolt has a USB 3.0 slot on the front (so you can charge your cell phone while you survey!), an RJ45 802.3af/at RJ45 slot (at = PoE+) to power your AP , and another RJ45 connection if you want to run iPerf with a device attached via Ethernet.
Back to the front, there is a small button to use for the Display Cycle switch (use a paperclip) which changes the display screen from battery voltage, to battery percentage, to off. Ventev warns that when battery voltage goes below 12 V, the battery is about to die, so fair warning!
Battery Basics
And of course, I took off the back cover (which by the way, Ventev says you can do) to look at the battery. It is not a standard lithium, but a lithium iron phosphate (LiFePO4) battery (and that’s a mouthful!). Checking online, you can see that this type battery is not only safer but has a higher capacity and power. Since LiFePO4 batteries do not break down after repeated recharges, lab results show these batteries lasting over 2000 charge cycles. Nice design feature, Ventev! And when you travel with the VenVolt (it is lithium, so it has to go with your carry-on luggage), it’s 4.5 lb weight will not load down your backpack! (I did find this battery replacement model online for $69.00.)
When fully charged and still connected to the wall wart charger, the display will say 18.4 V (when you remove the charger, the voltage will drop to about 13.5 V).
Display Cycle switch toggles between battery voltage, percentage and blank(off)
Test Driving the VenVolt
I mainly survey with Cisco products and since I had some of those available, I thought I would put them to the test. The two APs I tested were the 3702i and the 3802i (Note: Any resemblance of the Wi-Fi mount looking like a HiveRadar is merely coincidental!)
My testing consisted of setting both APs to full power on both the 2.4 and 5 GHz bands (that’s 23 dBm/200 mW). Then I tested again, using some lower survey power levels (17 dBm/50 mW).
Cisco 37021 AP
Cisco 3802i AP
Test results:
AP Power Level Run Time
Cisco 3702i 23 dBm 10 hrs 15 mins
Cisco 3702i 17 dBm 10 hrs 05 mins
Cisco 3802i 23 dBm 6 hrs 30 mins
Cisco 3802i 17 dBm 6 hrs 36 mins
Looks like the documentation Ventev has published is pretty accurate. The Cisco 3700 does last for over ten hours and the Cisco 3800 for about six and a half hours. I did notice that when the battery hits around 12 V/50%, that you don’t have a lot of time left before the VenVolt goes completely dead (the power lasted about thirty minutes to an hour after it hit the 12 V mark). The VenVolt kept the AP powered until it dropped under 9.8 V. However at this low voltage, I had no way to check to see if the AP was still providing the power levels listed above. Just a note: when the VenVolt hits 12 V, get out the charging power supply to recharge it!
But if the VenVolt can only power the 3800 for six hours, how do you complete a full eight-hour day of survey work? So, I also did a “how much recharge can you get on the battery over a lunch break?” test of the VenVolt. I let a VenVolt go completely dead and then put it on charge and set my timer for an hour. It came back to 100% — fully charged! Wow! I’m not sure if this was because this VenVolt was new out of the box, but if you can recharge over a lunch/dinner break for an hour, it will give you some confidence that your VenVolt will not die out in the afternoon.
So, what do I think about the VenVolt?
What I like: I really like the VenVolt a lot! It’s light to fit in my backpack or carry-on luggage. It easily charges overnight for the next days’ surveys. It is one of the few battery packs out there that will handle the higher powered APs like the Cisco 3800. Unlike some battery packs, it gives the voltage/percentage on the display screen. If you need to take a lunch break, it can do an hour recharge. And when you need to replace the LiFePO4 battery, that’s pretty easy and fairly inexpensive to do that as well.
What I would change/add: If the VenVolt had a couple of nice HD Velcro straps, it could attach well to my painter’s pole for APoaS surveys. And it would be nice if the VenVolt powered the 3802i for a full day of surveying. But I know there is a limit to battery size/weight compared to power time. I think most WLAN professionals that fly a lot would agree with me that a few pounds less in our checked baggage is a nice compromise. Also, when the voltage goes below 12 V, it would be a welcome feature if the VenVolt “beeped” at you to advise (we are busy freezing APs and do not have time always to check the voltage on the display).
What I don’t know: How well does the VenVolt power the new Cisco 4800 AP that was just released? I may need to do an update when I get a 4800 to test out.
Ventev, good job on the design of the VenVolt! It is a tool that will help all WLAN professionals get their work done faster with greater efficiency! (Take a look at the well-written user guides and spec sheets below).
Now, “orange” you glad you read this review? 🙂
The MSRP of the Ventev VenVolt is $499.
(Disclaimer: Ventev did not compensate me for reviewing this device. I did receive a VenVolt to test out for this blog post.)
gcatewifi 
Glenn, Good review! Don’t forget, the percentage display is a tad on the misleading side. I wouldn’t recommend using it, but rather get used to the output voltage ‘hockey stick’ on the back of the battery – which is very unique to the LiFePo4 batteries. Also note that the display voltage is what’s coming off of the wall when it’s plugged in. Your short ‘lunchtime’ charge sadly reflected “100% power output” not “100% battery charge”. You should plug it in for 30 minutes, with the display on the voltage view, then when you unplug it, you’ll have an accurate representation of the output voltage using the curve on the back. It takes some getting used to, but long gone are the days of a linear relationship between output voltage and capacity (common with lead acid batteries). Good job!
-Sam
Sam, and thank you for your additional update on the VenVolt! I think you additional comments are great–and it is good to know to watch the battery voltage. I know when it hit 12V for me, it was not long until the battery fully died (about 30-45 ins). Now, I imagine you have a 4800 laying around your lab somewhere….have you tried it with the VenVolt yet? 🙂