RadioReference on Facebook   RadioReference on Twitter   RadioReference Blog
 

Go Back   The RadioReference.com Forums > Scanners, Receivers and Related Equipment Forums > Uniden Forums > Uniden Tech Support


Uniden Tech Support - For discussion of all technical aspects of current or future Uniden scanners.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1 (permalink)  
Old 01-04-2018, 8:32 PM
jonwienke's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Jul 2014
Location: PA
Posts: 6,340
Default Trickle Charger Mod

I found a pad on the 436 front circuit board that is connected to the USB jack 5V power. It's labeled V_USB, the rightmost of the 3 pads in a row near the center of the photo.

The 436's inability to charge the batteries while it is powered on is one of its greatest design shortcomings. (I know, it's because of a BS California environmental regulation.)

Anyway, I realized that a simple trickle charge capability could be added to the 436 by connecting a 20Ω resistor and a SD103C diode between the USB power pad and the positive battery terminal. Given a USB voltage of 5.1V and a battery voltage between 3.1V and 4.1V, that particular set of components will result in a charge current of about 80mA when the battery voltage is 3.1V, tapering off to about 30mA when the batteries reach 4.1V. The idea is to fully charge a set of dead batteries over 36 hours or so, and keep them topped off while the scanner is plugged into USB power without frying them, so that a unit normally plugged into USB power will always have a fully-charged set of batteries.
Attached Images
 
__________________
Uniden scanner internal GPS installations--making mobile scanning work the way it always should have.
Reply With Quote
Sponsored links
  #2 (permalink)  
Old 01-04-2018, 10:22 PM
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Sep 2007
Location: shamong nj
Posts: 203
Default

a mod like that would be fantastic
__________________
scanning the pinelands of south jersey bcd436hp pro651 pro652 pro2006 pro2096 grundig satellit 800
Reply With Quote
  #3 (permalink)  
Old 01-04-2018, 10:59 PM
jonwienke's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Jul 2014
Location: PA
Posts: 6,340
Default

I'm going to order the parts and mod my 436 and see what happens. If all goes well, I will offer it as a $5 add-on option when I do a GPS mod.
__________________
Uniden scanner internal GPS installations--making mobile scanning work the way it always should have.
Reply With Quote
  #4 (permalink)  
Old 01-04-2018, 11:01 PM
jdeverett's Avatar
Member
  Premium Subscriber
Premium Subscriber
Amateur Radio Operator
Amateur Radio
 
Join Date: Apr 2005
Location: Venice, FL
Posts: 42
Default

Quote:
Originally Posted by lou9155 View Post
a mod like that would be fantastic


Yes, that would be a great option!


Sent from my iPad using Tapatalk
Reply With Quote
  #5 (permalink)  
Old 01-04-2018, 11:22 PM
pb_lonny's Avatar
Member
   
Join Date: Jul 2012
Location: Tasmania
Posts: 727
Default

Sounds like a great idea.

As a side note, the UBCD436PT DOES charge while in use
Reply With Quote
Sponsored links
  #6 (permalink)  
Old 01-04-2018, 11:25 PM
jonwienke's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Jul 2014
Location: PA
Posts: 6,340
Default

Evidently there aren't as many environmental Nazis in Australia as there are in California.

Can you get DMR for it?
__________________
Uniden scanner internal GPS installations--making mobile scanning work the way it always should have.
Reply With Quote
  #7 (permalink)  
Old 01-04-2018, 11:40 PM
pb_lonny's Avatar
Member
   
Join Date: Jul 2012
Location: Tasmania
Posts: 727
Default

Quote:
Originally Posted by jonwienke View Post
Can you get DMR for it?
Nope, reason I traded mine.
Reply With Quote
  #8 (permalink)  
Old 01-05-2018, 7:17 AM
Member
  Premium Subscriber
Premium Subscriber
Amateur Radio Operator
Amateur Radio
 
Join Date: Oct 2014
Posts: 27
Default

Would be interesting to get the WD for the scanner that does charge the batts to confirm the solution.

I am very interested in this as well as the GPS mod.

Great stuff Jon W!
__________________
(2) BCD536, BCD436, BCD996XT
Reply With Quote
  #9 (permalink)  
Old 01-05-2018, 8:20 AM
jonwienke's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Jul 2014
Location: PA
Posts: 6,340
Default

The parts are on order. I will post an update with test results next week.
__________________
Uniden scanner internal GPS installations--making mobile scanning work the way it always should have.
Reply With Quote
  #10 (permalink)  
Old 01-05-2018, 8:50 AM
dave3825's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Feb 2003
Location: United States
Posts: 2,023
Default

Jon, in the top right of your pic, just right of J403, what is the yellow item? Almost looks like an automotive fuse.
__________________
DMR436HP Br330T Pro 93 Pro 95
Arc330Pro ProScan Freescan BCDX36HP Easy Manual Id Tracker
Reply With Quote
  #11 (permalink)  
Old 01-05-2018, 9:12 AM
n9mxq's Avatar
Member
  Premium Subscriber
Premium Subscriber
Amateur Radio Operator
Amateur Radio
 
Join Date: Dec 2005
Location: Belvidere IL
Posts: 1,566
Default

Quote:
Originally Posted by dave3825 View Post
Jon, in the top right of your pic, just right of J403, what is the yellow item? Almost looks like an automotive fuse.
Looks like the usb to me.

Sent from my SM-G950U using Tapatalk
__________________
Gene
Is there such a thing as too many radios??
Transceivers, receivers, and SDR! Oh My!
Reply With Quote
  #12 (permalink)  
Old 01-05-2018, 9:26 AM
jonwienke's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Jul 2014
Location: PA
Posts: 6,340
Default

It's the USB jack, which has some kind of amber tape on it from the factory.
__________________
Uniden scanner internal GPS installations--making mobile scanning work the way it always should have.
Reply With Quote
  #13 (permalink)  
Old 01-05-2018, 9:29 AM
dave3825's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Feb 2003
Location: United States
Posts: 2,023
Default

Lol. Really looked like an automotive fuse before my morning coffee..

Maybe it's shielding tape to help usb noise.. lol
__________________
DMR436HP Br330T Pro 93 Pro 95
Arc330Pro ProScan Freescan BCDX36HP Easy Manual Id Tracker
Reply With Quote
  #14 (permalink)  
Old 01-08-2018, 3:01 PM
jonwienke's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Jul 2014
Location: PA
Posts: 6,340
Default

The parts arrived, and I've modded my 436, and everything works pretty much as expected. The diode-resistor combo allows about 80mA of trickle charge when the batteries are completely dead, and charge current tapers off to about 40mA as the batteries reach full charge. The pics below show the diode and resistor soldered together, then covered in heat shrink (to prevent shorting to the shield between the circuit boards) and soldered in place.

My thought is to offer this as a $7.50 add-on when I have the scanner apart for a GPS install.
Attached Images
  
__________________
Uniden scanner internal GPS installations--making mobile scanning work the way it always should have.
Reply With Quote
  #15 (permalink)  
Old 01-08-2018, 5:41 PM
W4EMS's Avatar
Member
  Premium Subscriber
Premium Subscriber
Amateur Radio Operator
Amateur Radio
 
Join Date: Dec 2002
Location: Middle Tennessee
Posts: 530
Default

Pics didn't stick. Re-send?
Reply With Quote
  #16 (permalink)  
Old 01-08-2018, 6:28 PM
jonwienke's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Jul 2014
Location: PA
Posts: 6,340
Default

Try reloading the page. I can see them.
__________________
Uniden scanner internal GPS installations--making mobile scanning work the way it always should have.
Reply With Quote
  #17 (permalink)  
Old 01-08-2018, 9:26 PM
W4EMS's Avatar
Member
  Premium Subscriber
Premium Subscriber
Amateur Radio Operator
Amateur Radio
 
Join Date: Dec 2002
Location: Middle Tennessee
Posts: 530
Default

Apologies Jon. RR site went down briefly as they were loading. Had to run an errand and didn't delete post in time.
Looks like a simple mod for steady hands.
Reply With Quote
  #18 (permalink)  
Old 01-09-2018, 3:28 AM
jonwienke's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Jul 2014
Location: PA
Posts: 6,340
Default

No worries.

The components are a SD103C Schottky diode with the cathode connected to the positive battery terminal to prevent battery voltage from feeding back into the USB port, and a 20 ohm 1/4-watt resistor. The resistor dissipates about 1/8-watt during charging, so going smaller than 1/4-watt is not advisable.
__________________
Uniden scanner internal GPS installations--making mobile scanning work the way it always should have.
Reply With Quote
  #19 (permalink)  
Old 01-09-2018, 6:38 AM
jonwienke's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Jul 2014
Location: PA
Posts: 6,340
Default

I've been running a couple 436s with this mod overnight, and the batteries are definitely charging, but are not overheating. Using an IR thermometer, the GPS patch antenna measures 76F, and the batteries are only 72F. Battery voltage has risen from 3.11V to 4.13V over 10 hours.
__________________
Uniden scanner internal GPS installations--making mobile scanning work the way it always should have.
Reply With Quote
  #20 (permalink)  
Old 01-13-2018, 8:49 PM
jonwienke's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Jul 2014
Location: PA
Posts: 6,340
Default

So I did some tests with some 800mAH 14500 Li-ion batteries. 3 of them in parallel is roughly equivalent to 3 NiMH cells in series. I did a comparison of battery life, and the NiMH cells lasted about 8.5 hours, and the Li-ion cells lasted about 9.75 hours. The performance benefit is there, but probably not worth the hassle of coverting the scanner to use them.
__________________
Uniden scanner internal GPS installations--making mobile scanning work the way it always should have.
Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -5. The time now is 11:42 PM.


Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
All information here is Copyright 2012 by RadioReference.com LLC and Lindsay C. Blanton III.Ad Management by RedTyger
Copyright 2015 by RadioReference.com LLC Privacy Policy  |  Terms and Conditions