All,

I know many of you of have tried different power solutions and I was hoping maybe you could give me some thoughts on a solution that we're contemplating. Like most surveying firms we have a large portion of 2-way radios. We've always used Motorola branded units. So we have large ammount of rechargeable batteries and chargers. Our radio guy suggested we use one of battery packs we use on our Radius SP10 radios. Here's some specs...

Motorola branded battery
Model: HNN9044AR
Ni-cad
7.2V
630 mAh

He's going to attach a 9v battery snap that will attach to the external battery pack connector.

I understand that by using such a solution it is not supported by Ashtech/Thales, but we can no longer keep buying throw-away batteries. It gets old and expensive doing that every 2 days.

What we're wanting to know is if something like this is going to work and if so, what kind of life do you think we expect from a full charge?

Thanks in advance for the replies.

Tommy McClain

The rechargeable batteries that Robert Snow bought seem to work quite well. I have been trying out a pair of them but have not tested the six and two myself.

Robert reported many hours of data collection using the six and two of the rechargeable batteries he described.

The battery pack cable that comes with the external power kit has essentially the same electronics as the cables from Magellan that can be used to power receivers from the power receptacle in your car. I have used a ProMark2 and a MobileMapper in my van with the cable I bought from Magellan. I cannot see a reason why your radio battery would not work. How long it will run the ProMark2 is something you will have to tell the rest of us.

I recently found a Panasonic charging system at Costco. It is model number BQ-390. It comes with 6 AA batteries and 2 AAA batteries. The batteries are Ni-MH and have a charge capacity of 2100mAh. The batteries are quick charged in just a few hours. Costco price was just under $20 for a charger and the set of batteries. I bought three.

The problem with most rechargeable battery systems is that they only run around 1800mAh. The ProMark2 survey grade antennae require more umph to run them satisfactorily. These Panasonic batteries were designed for digital cameras and have more than enough goofu (Swahlii word for strength or power) to do the job.

I ran tests on the batteries at night to simulate cold conditions. Temperatures during nighttime hours in Southern California were between 38°F and 45°F. A pair of batteries consistently ran the ProMark2 for over 9 hours. Interestingly, I noticed a consistent difference of about 7 minutes between receiver IW01 and IW02. It didn’t matter which batteries or position the units occupied.

In my opinion, the cost of the disposable batteries is negligible in the scheme of things. My worries come from chucking 3 pairs of batteries a day in the trash. At 4 days of use average on my units per week, that’s 2 dozen batteries worth of toxic/hazardous waste going in a landfill from my office every week!

I talked with Kelly Bellis at great length recently regarding off-board battery power. The best set-up I’ve run across is a RoadPro 12V battery pack with the cigarette charger from the Magellan 330 spliced into the receiver fitting from Ashtech’s external battery pack. The cigarette charger has a power transformer/reducer that will take 12V power down to the power required by the ProMark2. If the cable is spliced between the ProMark external fitting and its power reducer and the power reducer and plug end of the 330 cigarette charger, the power should be properly conditioned. Please note that I have not yet tried this and can make no definitive statements about it effectiveness or suitability. You are on your own if your receivers turn to molten masses of blue plastic!

Links to the best cost source for the parts are:

RoadPro battery pack - $24.89

Magellan 330 cigarette lighter power cord - $16.22

RoadPro voltage meter - $12.95

Hayes Instrument – ProMark2 external power supply - $95

Cheers, all!


Ian Wilson, LS CA

(if you end up with fried ProMarks, then this was posted by Jim Thistleton, Registered Surveyor, Belize)


Modified By D. Ian Wilson on 12/30/2003 at 6:07 PM

We spliced the pm2 external power cable to run on a 12v drill battery. I tested it on a Magellan pioneer before the blue box. If the wires get connected wrong the thing just will not work. No damage! Just switch the wires back and power up. The craftsman 12v has never shut off on us even after 10-hour sessions at 20deg


I recommend getting a cheep Magellan for a battery test but I do not think there is much 2 worry about. I think it specs up to 35 volt

I've been using the RoadPro Battery Packs for over a year. We run 4 PM2's mostly static with long occupation times. Converted two of the Magellan Adapters on the work bench, and the other two were converted by a salesman from Hayes Instrument. They fit conveniently into the Blue Bag. Never had a battery pack fail and we charge them once a month during the summer and once every couple of weeks during the cold months. They can be charged at the office over night or in the truck in about 2 hours.

I'm located in SE Ohio and have worked in a range of -10 to 90 degrees. Not to mention wind chill!

The major problem is the weight. Although they fit in the bag, they more then double it's weight. A second annoyance is the cable being attached to the cradle. If you are not using the RoadPro you still have the cable dangling from the cradle. A minor problem that feels like a major pain at times.

I understand the problems with disposable batteries going to the landfill and complaints about cost of buying disposable batteries, BUT I use the RoadPro’s so I don't lose money. When we started using the units 14 or so months ago the most aggravating thing was to discover a unit went down early and a second occupation was needed. In just a few locations where this happen we lost over 4 hours of time a $340 loss. That was much more then we paid for all four external RoadPro Units.

I’m still glad we purchased the packs.

SurChas

Any small lead cell battery (such as for a motorcycle or lawnmower) will power a base for a week. Rechargable ni-mh will power a rover for a good 1/2 day, extras can be easily carried. I notice some 2.3 ah ones on the shelves lately. I happen to have a few motorcycle batteries which will not crank a cold engine anymore but will happily power a PM2 for a few days. The Landrover has a dedicated compartment and charging wiring for this small battery which goes where ever I go.