I had the displeasure of running out of power before I ran out of daylight on a project earlier this month. It occurred to me that I don’t spend anywhere near as much time worrying about power issues as I did at one time, but, obviously, power issues can still be a problem.
Back during my GPS days, the Trimble receivers we used took off-the-shelf camcorder batteries. They were heavy and didn’t last more than a year or so but they were readily available and as a result relatively inexpensive. For longer duration sessions we would use gel cell batteries but even those were wired together in-house.
Then I got into laser scanning…
Power issues were all consuming in the early scan days (my early scan days, that is). The batteries were bigger and far more expensive than car batteries. In fact, I remember the day that I found out that a replacement battery for my HDS3000 cost more than the truck I was using for fieldwork! AC adapters did not come along for a couple of years. I couldn’t get a battery tech to crack open one of those old HDS3000 batteries to install replacement cells for any amount of money. Seeing that internal circuit board always seemed to scare them off a bit. However, the laptop would always die before the scanner did so it was hard to complain.
Thankfully, we are seeing some improvement. The biggest is with the Leica C10. Having hot swappable batteries that use the same charger as other Leica measuring devices is great. However, I’m having to remember some of my old trials and tribulations from the camcorder battery days. I ran out of power on this last job because I plugged all of the batteries up to charge in one of our hotel rooms. When you do this all of your power is coming through one or two breakers (especially in older hotels). This will charge the batteries and they will show through the indicator lights that they have a full charge but the amps will have been low during the charge due to the large pull of multiple batteries on multiple chargers. So, you get up in the morning, everything shows a full charge, you start scanning and by lunch you’re going through batteries like beer at a frat house.
Lesson re-learned: We now separate the batteries and chargers and send them to different rooms for charging.
One newer development is the increased efficiency and decreased size of portable generators. Some of these are very quiet and with proper power conditioning and surge protection they are quite suitable for use as AC power for both scanners and laptops. However, they still require a hot permit and need to be used in areas that allow for exhaust from the engine. Another option for interior or non-hot-work areas are computer battery backups or UPS units. These are designed for running your computer when the AC power is interrupted. The idea is to give you time to save your work and then power off. However, they can be used to greatly extend the battery life of a laptop. I would recommend plugging the laptop in and running off of the battery first and then using the laptop battery. Otherwise the laptop recharges itself from the UPS which results in a shorter duration of battery life as opposed to pulling the UPS power through a fully charged laptop battery. I would not recommend using them to power a scanner as the weight to battery life ratio is abysmal for such an application. The upside is that they double as an excellent power conditioner and surge protector when you get back to the hotel room.
I hope that more manufacturers move to hot swappable and/or off-the-shelf batteries for imagers. Laptop batteries are getting better but the inevitable move to tablets for scanner control (when not using the onboard controls) will put the scanhead on the battery life hot seat again soon. I often run our C10s through a RDP on my iPad. Doing so, I can conduct two full days of scanning (plus navigation, email, FaceTime with the kids at night, etc.) before I need to charge my iPad again. I know many of us are looking toward the Faro Focus 3D to define the size of the next generation of scanners but I’ll take something close to the size of a C10 or Z+F Imager if the batteries can keep up with my iPad.
One final note: I saw a post on LinkedIn this weekend that a Faro Focus 3D was stolen from the Grand Gulf Nuclear Station in Mississippi. If you are approached about buying one I hope you will contact Kimble Slaton, of CTSI Consulting Engineers & Surveyors, to make sure it is not his. I’ve had a few pieces of equipment stolen over the years and it makes you sick to know that anyone capable of using it knows exactly what it did to you to lose it. If we make sure that there is not a market for reselling stolen equipment we all stand a better chance of keeping our own equipment from being stolen.
