Many thanks to SWLing Post contributor, Jason Walker, who shares the following advice:
H501x Tecsun Battery Issue – False Low Battery Indication – Solution
As a H-501x owner I have found a solution to ‘false’ low battery indications on the radio, having tried several high quality batteries to lengthen the runtime, even a high capacity 3500mAh Fenix, without much success.
Last week, I noticed that when the radio was physically moved or tapped, the battery indicator would vary to low and radio cut out. I have traced this to a poor battery terminal connection (poor spring strength primarily) on the battery bays A & B.
By using a very light sanding of the positive battery contacts in the radio with fine sandpaper and cleaning of the 18650 battery terminals, not only does the issue go away, but the radio runtime improves significantly and battery capacity indicator returns to full.
I would be interested to know if anyone else has come across this issue? This may also be a cause of low H501/x runtimes mentioned in other posts.
Stronger battery springs with higher tension would improve the battery to terminal connection, as a product improvement suggestion for Tecsun or perhaps a local mod?
Jason Walker, Christchurch, New Zealand
Thank you for sharing this, Jason! No doubt a very easy modification that produces meaningful results. Again, many thanks!
Have the same issue on a brand new H-501x.
I sanded terminals, cleaned terminals and batteries with contact cleaner and slightly stretched the spring contacts.
Unfortunately this has not solved the issue.
Have no idea what to do now. Very disappointed to be having such problems given the high price I paid for this radio.
I just got an H-501x and was noticing battery problems today. After charging all day and turning the radio on and unplugging the charger, My battery indicator was flashing low battery. With charger plugged in it is showing full charge. Glad to read this so I can try cleaning my terminals as well in hopes this fixes the problem.
I am so glad you posted this . I was about to return the radio. Often if I turned the volume up , the indicator would flash and the radio cut out . I have stretched the springs and cleaned contacts with cleaner. Problem gone . I am well pleased . Why didn’t Tecsun sort this out before production . It’s not rocket science is it . Many thanks .
Well I’ll be darned- lightly sanded the contacts, cleaned with rubbing alcohol, stretched out the springs a bit, and it worked!
Thank you for sharing this! I thought I had a charging issue with my radio and was debating on what next steps I would take. I performed the fix here and it’s now charging like it was when it was new! It sounds like the materials used in the battery terminals is more prone to oxidation. I’ll also order a can of Deoxit… This should probably be fed back to Tecsun since this seems to be a common issue.
I also had the same issue. Did not have any sandpaper. So I tried magic eraser (melamine sponge) the thin sheet version. Followed by wiping with alcohol pad.
So far it has seemed to fix the problems.
Thanks for the tip.
Will try the Caig De-Oxit.
I have had the same issue as you on both the A & B battery ports. Thanks for sharing your solution. I’m wondering if carefully extending the springs length with a pair of pliers would be beneficial as well?
Instead of sanding contacts, I use a product that increases contact conductivity without creating shorts. The product is Caig De-Oxit. It is available in a spray or liquid. When I change flashlight batteries, I put some on each end of the battery, and I can see a noticeable improvement over battery replacement alone. This chemical starts out well initially, and improves over several hours. Periodic application every 3 or 4 months is recommended. I use the liquid version and apply with a Q-tip.
Same here. I’ve been using De-Oxit for over 20 years.