Rechargeable External GPS Project

[DennisKink]

Are these for sale now?

 

[buddrousa]

Yes he custom makes them they work great.

 

[jonwienke]

One clarification: If the only scanner you have is the 536, you can get by without having a battery in the GPS by modding the 536 (or any other Uniden scanner with a DB9 GPS connector) to supply power to the DB9, and putting a DB9 connector on the GPS, as shown here:
https://www.radioreference.com/apps/classifieds/showproduct.php?product=8647&cat=13

This is cheaper than the rechargeable GPS option, but requires modding the scanner..

If you want to use the GPS with a 536 and a 436, and don't want to mod either scanner, then the rechargeable GPS is needed.

 

[DennisKink]

So this setup would eliminate the 12v to the cigarette port cable? You would only have a single cable between the scanner and GPS?
And what would happen if the batteries go bad?

 

[jonwienke]

The purpose is to have a single cable between the scanner and GPS.

The GPS battery will need periodic recharging, which can be done with a standard micro USB cable. If you mod the scanner to supply power to the GPS, then the scanner can recharge the battery when it is not running on its battery.

If the battery fails it can be replaced.

 

[buddrousa]

Dennis I opted for the 3 14500 batteries which should power the gps unit for 72 hours before recharging.

 

[DennisKink]

The purpose is to have a single cable between the scanner and GPS.

The GPS battery will need periodic recharging, which can be done with a standard micro USB cable. If you mod the scanner to supply power to the GPS, then the scanner can recharge the battery when it is not running on its battery.

If the battery fails it can be replaced.

Could there be a cable adapter on the scanner end of the cable to charge the batteries from a USB type plug, like what you would use to charge a cellphone in a cigarette socket? This is in case you have the GPS unit on your roof and the wires routed through the frame.

 

[DennisKink]

Dennis I opted for the 3 14500 batteries which should power the gps unit for 72 hours before recharging.

Yeah that’s what I would order. Is the 72 hours total run time? I mean if you turned it off for a week after using it for say 24 hours, would you then have 48 hours left when you turned it back on?

 

[jonwienke]

Could there be a cable adapter on the scanner end of the cable to charge the batteries from a USB type plug, like what you would use to charge a cellphone in a cigarette socket? This is in case you have the GPS unit on your roof and the wires routed through the frame.

There's no need to have the GPS unit on the roof outside in any normal vehicle. The GPS modules I use will maintain satellite lock under the seat of a typical SUV in most cases. So if the unit is on the dash, it will generally only lose satellite lock in a tunnel or the lower levels of a multi-story parking garage.

A 3-battery unit will give 72 hours of total run time. So if you used it one hour per day, it would only need charging every 72 days. The unit automatically turns on when it is plugged into a scanner that is powered on. If you power off the scanner, or unplug the GPS, it will automatically shut off. There is a micro USB port on the unit for power and charging.

 

[Dewey]

Great work Jon!!! A couple questions if you don't mind...
1) Is there any protection and/or danger with these 14500 batts? (I don't know 14500s, but I know that 18650s can do some really bad things if not properly protected for overcharging or deep deep deep discharging).
2) Will you consider an option for more discrete lights so the unit does not call attention when sitting on a dash or near window?

Again, GREAT WORK!

EDIT: I'm sorry, one other question. Will the straight through serial cable work with the Uniden portable to serial GPS cable? This will give the user the choice of using the GPS on a portable or mobile, while still only requiring a single wire rather than a rat's nest.

 

[jonwienke]

The charger board I use has over and under voltage protection, as well as charging current limits.

The lights are part of the module. If you turn off the scanner or unplug the GPS then the lights turn off.

You can connect the GPS to a handheld scanner with the Uniden cable. A straight-through cable would just be an extension cable in that case. It would only be the primary cable for a mobile scanner with a DB9 connector.

 

[jonwienke]

FYI, I have just run out of cases. I have more on order, but it will probably be another week or two before they arrive.

 

[DennisKink]

FYI, I have just run out of cases. I have more on order, but it will probably be another week or two before they arrive.

Does this include mine?

 

[jonwienke]

I believe you got the last one. I will check in the morning to confirm.

 

[buddrousa]

Jon I may get you to build me a 9 Pin like my one you built me to work as a second unit when I get my SDS100 or use one of my 536's.

 

[jonwienke]

Does this include mine?

You got the last one

 

[DennisKink]

You got the last one

Aww sorry everyone else. Not!!

 

[kh6sz]

I'll be patiently waiting for mine.

 

[jonwienke]

I'll post an update when the shipment comes in.

 

[jonwienke]

I'll be patiently waiting for mine.

You got your order in before Dennis, so you're good. I'm running tests on both of your units, and they should go out tomorrow.