aefong UV-5R HAM radio charging stand malfunction

[alia176]

I got an issue with my Baefong UV-5R HAM radio charging stand that maybe someone else here has experienced.

The radio is a week old and the charging stand seems to be showing an error code by displaying a steady green light with rapidly blinking red light. The manual says this is an error condition and apparently this is fairly common. This explains why the battery is only good for six hours on standby. Has anyone else experienced this issue? If so, what's the fix? I sent the Amazon seller an email.

I took apart the charging stand and nothing seems to be amiss. There is a micro chip there, a diode and a cap. I'm guessing it's a simple rectifier and the chip is a comparator of some sort, can't read the number on it.

Thanks for any insight.

 

[george_tlc]

The chip is the charge controller for the li-ion cells. It nominally has to output 8.4V (4.2V per cell, 2 in the pack) and control the max current etc.

So, when you place your UV-5R into the stand it should go red (green/red flash with nothing inserted), while charging. Then green once it has reached the nominal 8.4V and charge current is low enough that it calls it 'done'.

Just opened mine to look inside - beautiful work - it's rusting

cheers,
george.

 

[alia176]

The chip is the charge controller for the li-ion cells. It nominally has to output 8.4V (4.2V per cell, 2 in the pack) and control the max current etc.

So, when you place your UV-5R into the stand it should go red (green/red flash with nothing inserted), while charging. Then green once it has reached the nominal 8.4V and charge current is low enough that it calls it 'done'.


cheers,
george.

In my case, the LED turns a solid red when I first insert the radio into the charger. At least this way I know that both contacts are being made. Then after a couple of minutes, red/green flashing starts and stays in that mode all day/night.

Nothing looks messed up from what I can tell. Not sure if the chip is malfunctioning though. I had to ask my ten year old daughter to read the chip "HXN-WS ?4916"

 

[george_tlc]

^ I'd measure the voltage on the 2 wire contacts (that solder to the contact pads for the radio battery charging) and see what is shown. Should be anything from about 6V to 8.4V depending on state of discharge of your battery.

I would verify you have clean contacts and enough tension to make good electrical contact to the battery pack charging pads (give them a clean).

The green/red flash indicates the charger thinks the battery is not plugged in (voltage >> 8.4V). Measure the voltage with the base bottom removed and the UV5R pushed in and report back...

cheers,
george.

 

[alia176]

^ I'd measure the voltage on the 2 wire contacts (that solder to the contact pads for the radio battery charging) and see what is shown. Should be anything from about 6V to 8.4V depending on state of discharge of your battery.

I would verify you have clean contacts and enough tension to make good electrical contact to the battery pack charging pads (give them a clean).

The green/red flash indicates the charger thinks the battery is not plugged in (voltage >> 8.4V). Measure the voltage with the base bottom removed and the UV5R pushed in and report back...

cheers,
george.

8.34v - empty charger, light blinking
8.06v - battery ONLY (no radio) in the charger, light turned red.
8.34v - while battery in the charger, voltage went back up to 8.34 and light went from red to blinking mode.

Contacts are making good contact and are clean. They better be clean since the radio is two weeks old but I cleaned them anyway.

 

[george_tlc]

Well, anything near 8.3 - 8.4V is fully charged...

Maybe something weird going on in the battery pack itself when it is fully charged and the charger detects open circuit and so blinks green/red.

i.e. it sounds more like a battery/contact issue than the charger itself.

Mine went green after about 20mins (battery has just been 'sitting' for a few months) at it was 8.31V and presumably very low current flowing in. With no battery (and the green/red blink) with my scope I saw it pulsing between about 8.4V and 8V, presumably trying to detect a battery and complaining that there wasn't one connected.

No idea on the charger chip since some google searching finds nothing useful (i.e. no datasheet). Likely some china chip for local consumption only.

cheers,
george.

 

[alia176]

Thought I'd circle back and update the gang on what I found out. The Amazon vendor has been excellent to deal with and sent me a second radio. In the meantime, I bought another radio for less than $20 from a different vendor. Well, it turns out that the original radio and the second radio from the same vendor has a batch of bad batteries.

I notified the vendor of this finding and they've started a fact finding mission with their battery vendor. My original vendor even offered to refund me $10 so that I can buy batteries on Amazon and I told them to not to worry about it. Their customer service has been great and I'll give them five stars on Amazon.

 

[george_tlc]

Glad to hear you have the issue resolved. Yeah, seemed like a battery/contact issue and the vendors have admitted bad batteries.

I've had my pair a couple of years and they've been 'reliable' so once you have a good battery in them, you should be good to go until the warranty expires

cheers,
george.

 

[alia176]

I'm curious about the battery packs. They're made so well but I wanted to take them apart and see what I can patch up. I'll prolly ruin them in the process but it's worth a shot. Hopefully I won't slice my fingers open trying to pry apart the well made package!