Powering GPS antenna

Cantaloupe · Occasional Visitor Joined: Aug 09, 2007 Posts: 20

Hello,

I'm doing work for a company which has provided me with an iPAQ 19xx, an Arkon Powered Mount, and a GPS antenna. It all works well in the car. However, I personally know the area and some of it is better covered on foot or by bike.

How can I power the antenna and connect it to the iPAQ (which is operating on is battery)?
OR
How can I power the mount (using it to connect the iPAQ with the antenna and power the antenna) without constantly using the power to recharge the the iPAQ?

An electronics store suggested that I carry around a large, heavy and impratical 12v 7amp battery. There has to be a better way.

I'd appreciate any suggestions or confirmation that the heavy 12v battery is the only way.

mikealder · Posted: Thu Aug 09, 2007 5:10 pm Post subject:

It is possible to make your own power box to supply the devices while mobile away from the car, I detailed such a device a while back which comprised of a box, a 12V socket and 8 high capacity AA rechargable cells. It wasn't too heavy or large and is easy to make, when I get home to the proper PC I will search out the post (its too difficult on a mobile phone).
Some of the components are no longer available but to find suitable alternates won't be difficult - Mike

Cantaloupe · Occasional Visitor Joined: Aug 09, 2007 Posts: 20

Oh, thank you. I spent the day being told "No, its impossible."

I'll look forward to the information. In the meantime, I will get started on buying/connecting the battery holders for 8 AAs and a 12v cigarette socket.

mikealder · Posted: Fri Aug 10, 2007 6:31 am Post subject:

Have a read of some of my posts in This Thread which details the box, certain parts are no longer available. One of the other Mods has the actual box - I will try and get a photo of it to post up later - Mike

Cantaloupe · Occasional Visitor Joined: Aug 09, 2007 Posts: 20

I read the thread. Thank you for finding it.

I have a question, if the powered mount (needed to connect the GPS antenna/receiver with the PDA) is plugged into the 12v socket attached to the 8AAs, how do I prevent the iPAQ from using the 8AAs as its battery wears down?

I believe that I can use a hard case meant for a small digital camera or cell phone as the box

Pc-Mobile · Posted: Fri Aug 10, 2007 12:58 pm Post subject:

Cantaloupe · Occasional Visitor Joined: Aug 09, 2007 Posts: 20

mikealder · Posted: Fri Aug 10, 2007 2:18 pm Post subject:

2700mAH AA rechargable cells will typically give you 7 Hours use powering both the iPAQ and the GPS before they let go, at this point there would be no power available for the GPS but you can still use the iPAQ as its battery would be at 100%.

The mk2 system I built powered my iPAQ4700 for around 7 hours before switching to its internal battery - the 4700 is a larger screen and faster processor so will demand more power in use - Mike

Cantaloupe · Occasional Visitor Joined: Aug 09, 2007 Posts: 20

7hrs is great!

I've already bought the battery holders (4x2). I'm having a bit of a problem finding a 12v socket. However, if I can't find it at the store where I'm going, I will use the bottom half of a car cigarette lighter and make sure that I cover all of the exposed metal parts w/electrical tape.

I'll let you know how it's going.

mikealder · Posted: Fri Aug 10, 2007 3:22 pm Post subject:

Try a caravan sales or showroom or local motor home type place they often sell these type of sockets, even a marine shop for speed boat accesories is even better as the ones they supply often come with a waterproof cover when not in use. The 12V socket was dicontinued by Maplins quite some time back IIRC - Mike

Cantaloupe · Occasional Visitor Joined: Aug 09, 2007 Posts: 20

I went to a couple more stores but I still didn't find a socket. Ironically not even a cigarette lighter. I'm not to worried. As it stands now, I'll pull the one out of my car.

The problem, which now has me concerned, is that I can't find the batteries. I found one set of 4 2700mAh in a packet with a charger (K&H brand--never heard of them) they don't seem to be sold in packets alone to make up the 8. The well known brands I can only find with a lower mAh the highest was 2000 or 2100.

Should I go with the lower mAh or mix them?

mikealder · Posted: Fri Aug 10, 2007 9:23 pm Post subject:

Don't mix batteries of this type, that is dangerous and can lead to a fire.
Look at Maplins or CPC for a good deal on NIMH cells and correctly rated charger - Mike

Cantaloupe · Occasional Visitor Joined: Aug 09, 2007 Posts: 20

I wish I had the time but I promised to send some data by Monday.

There are some good deals at Maplins. I'm looking at roughly a 60E Shocked

output on batteries and a charger which I will only need for a 1wk. It is still better than having to get my car towed off of some cow path.

I'm going to a store specializing in batteries. Maybe I can find the 2700s there.

mikealder · Posted: Sat Aug 11, 2007 11:14 am Post subject:

If you cannot find 2700 just use 2500mAH
And what do you mean by 60E Shocked

is that Euros? - Mike

Cantaloupe · Occasional Visitor Joined: Aug 09, 2007 Posts: 20

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