A while back I wrote about my handy little Cradlepoint CTR-500 mobile router and promised to follow up with my battery power solution.  I have had 6 people poke me over the last month for more information on the battery setup (that is 5 more people than I thought would ever read this blog), so here you go.

I ended up going through a couple of different battery solutions before finding one that had enough current to properly boot the device AND had good battery life at the same time.  In the end I went with the Tekkeon MP3450 and I have been extremely pleased with it.  This battery is really much larger than I really needed for the CTR-500 but it has the added benefit of being able to power almost any device I use remotely except for my MacBook Pro.  I bought mine from eCost.com for a ridiculously low price of around $80 but normally they go for over $100. 

I have powered the CTR-500 for over 16 hours of average usage and used the battery for charging my phone and iPod several times over and still had at least one light on the battery meter so I guess I have never really gone far enough to find out its limits.  This battery also has a USB port for charging/powering any USB or min-USB device and comes with a handy little retractable USB cord.  They also supply a bag full of little adapters for almost all common DC connectors (I couldn’t find any devices that didn’t have a matching adapter, other than proprietary phone connectors).

One issue I have is that I can’t power on the router with the Sierra 597E Express Card already inserted.  The router seems to cycle repeatedly in a loop which I think is because it can’t get enough surge current to power up the router AND the card.  I haven’t tried any other cards, but I assume this will be true for others.  Either way, it isn’t a big deal to insert the card after the router starts to boot (I barely give it 2 seconds before I pop it in and things work great after that). 

One word of caution, the MP3450 has adjustable voltage from 5v to 19v and it is easy to #@ck up and fry your nice little router.  I know, because I did it….. once.  The top of the unit has a row of lights that serve several purposes.  Normally it displays the currently selected voltage, which for the CTR-500 is the first, and default setting of 5v.  On the side of the battery there is a switch that locks the voltage and when you press the button on top, you see battery level indicated by the number of lights.  If you unlock this switch, a press of the button changes the voltage.  So the moral of the story is, don’t ever leave the damn thing unlocked and throw it into your backpack where something can accidentally press the button several times as you walk down the street until the voltage goes up to where it pops, emits a faint little bit if smoke, and renders your $160 router completely useless. 

So now that I have that off my chest, I really love the totally mobile setup and as you can see from the pictures the battery is about the same overall form factor as the router and the express card.  I usually have them all set up just like the picture and I wrap an elastic/velcro strap around them all to make a nice little package to throw in my backpack.  What I would really like is to find a removable hard drive case with a little reinforcement so that I can fit it all in there perfectly and use small external antennas, but that is getting a bit overkill.  Then again…