Goal0 Sherpa 120 Battery

Background

After I got and reviewed a Goal0 Guide 10 4AA Battery Recharger a couple of weeks earlier, I decided to jump in and get the big battery. I fly on Southwest and Air Tran a lot, and it’s apparently magically impossible for them to have power outlets on their planes, even though every other 737 operator in creation has them. So it’s either deal with 90 minutes of movie-playing time, or go without. Well, it was. This thing is a hoss, it weighs about three pounds, takes arbitrary power in, and provides power out from a standard USB-B female socket at 5 vdc, and some arbitrary coaxial plug at 12 vdc. It comes with a near-proprietary charger and a converter from the output socket to a standard car lighter socket.

There’s also Sherpa 50 Battery, which I haven’t tested, which seems to be almost exactly the same thing, but with a smaller battery set.

Construction

The construction is, again, rock solid. This thing is, for all intents and purposes, a brick. There’s a slight chance of damage to the status indicator and power button, but after a month of heavy travel I haven’t even come close to hurting them.

The thing weighs about three pounds. It’s got a lithium-iron phosphate (LiFe) battery instead of the more common lithium-ion/lithium-polymer batteries that most laptops and phones have. This gives it about 15% less energy density per mass, but the battery will hold a charge longer and not degrade as fast (yeah, that 1-2 year laptop battery lifespan should not apply to this one).

Specifications

From the specs, it looks like the “120” is a reference to 120 watt-hours of power storage – the 30 watt solar panel charges it in a minimum of 4 hours. That means it would keep my cell phone running for a month (assuming I use about half of its battery’s 5.55 watt-hour capacity a day). Or my laptop running for about six hours (depending on how hard I ran her – it’s a “full sized” laptop, so netbooks and tablets will run longer).

There isn’t much to it. On the front face, it has a coax charging port, power indicator, battery meter, power button, usb output port, and coax output port. On the back, it has a coax plug and socket for daisy-chaining.

The power button switches the unit into charge/chain mode or off.

or off. The power indicator is solid green when it’s in charge/chain mode, and dark when it’s off.

The charge socket is an uncommon coaxial socket that fits the included proprietary charger and accepts 15.3 v.

One output is a USB-B female dumb (doesn’t negotiate) socket with the regular 0.5 A at 5 vdc.

The other output is an uncommon coaxial socket that fits the included proprietary adapter to a standard cigarette lighter, and puts out 10 A at 12 vdc.

The daisy chaining plugs/ports on the back are uncommon coaxial and appear to accept only 12 vdc, but that’s just going by what it says.

Observations

The pack only charges from the proprietary charger (or perhaps from another of these units connected to a proprietary charger), or from a Goal0 solar-panel like the Nomad 13.5M. That means that for any significant use, I have to carry a bulky solar panel or a bulky single-purpose charger. I tried using my iGo Travel Charger to charge it (and the standard tips fit all of the unit’s uncommon ports), but the charge sensed an input mismatch and turned off.

I’m puzzled as to why Goal0 did not use the 12 vdc input port for charging by default, and have it use a standard cigarette lighter adapter – that would allow an option for charging in a plane or car too. I suppose the 12 volt output has a coax port to save space, but I have to carry the coax-to-lighter dongle any way, so there’s no real savings.

It also should have been easy to tie a voltage regulator into the primary charge port, to allow it to accept a wider range of inputs.

Several of these points lead to interesting experiments (what happens if I run my 19.1 vdc laptop charger through a voltage regulator and into the 15.3 vdc charge port? Or do the same into the daisy-chaining port? That’s for a later post.

It also seems more bulky than necessary. I’m sure some is ruggedization, but it takes up a lot more space in my travel pack than I’d normally want to dedicate. I’m sure some of the flashy case could be removed.

Conclusion

This is an attempt at getting the best of the worlds of rechargeable lithium battery technology and lead-acid/acid-mat batteries. As far as that goes, it’s not a bad shot. It approaches the lower weights of rechargeable lithium batteries and has the life span of a lead-acid battery.

Unfortunately, the designers missed several important design points that cost this unit a lot of practicality. The requirement of a proprietary charger and the complete inability to charge from a DC power source significantly reduce the utility of this device, especially considering the cost. Given that practically every laptop provides USB power any time a battery or power adapter is connected (even when sleeping or powered off), I’d be MUCH better served by getting two spare batteries for my laptop instead. And it’s big enough that it doesn’t feel “electronics-heavy”, but like there’s dead air inside – a huge detriment for anything used in travel.

Sorry, Goal0, this gets one and a half out of five stars.