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Strange battery behaviour in portable radio?

David B

Dec 29, 2017
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Hi, I bought a small portable Crypto DB100 DAB/FM radio to use at work. The trouble is the radio batteries won't even last for one day. I also have an old portable Roberts AM/FM radio and the batteries last for at least a week in that one. I have used AA Uniross rechargeable batteries in both radios. The Crypto takes 4 batteries, the Roberts only needs 2. I tested the batteries from the Crypto last night after getting home from work and found 2 of the batteries were about 1.25 volts but the the other 2 batteries (from the same Crypto radio) were down to less than 0.5 volts?! I checked the batteries again this morning and found the 2 batteries that had gone down to less than 0.5 volts had recovered to about 1.2 volts ( they were not put in a charger, just left on the table overnight). I just put the same 4 batteries back in the Crypto radio and it powered up briefly and then went off. I immediately checked the batteries again and 3 of the batteries were still about 1.2 volts and one had dropped to about 0.9 volts but was recovering while my multi-meter was connected to it back up to roughly 1.2 volts. Anyone one any idea why this might be happening? Could it be the radio or batteries causing this? I am assuming my multimeter is working properly.
 

bertus

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Nov 8, 2019
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Hello,

It sound like bad batteries.
The 0.5 Volts batteries are likely to have a high internal resistance.
What happens when you run the crypto on new fresh batteries?

Bertus
 

Alec_t

Jul 7, 2015
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IIRC, early DAB radios generally gobbled batteries faster than traditional AM/FM radios. Don't know if that's true of modern radios.
But yes, sounds like bad batteries. They might not have liked being run down to 0.5V.
 

Martaine2005

May 12, 2015
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Try normal AAs not your rechargeables.
Definitely sounds like battery issue.

Martin
 

David B

Dec 29, 2017
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Thanks, I dont want to use non-rechargeable batteries (too expensive). I dont have any brand new rechargeable batteries but I do have a different make I could try in the radio (some Instant 2500mAh). I'll see how these fare in my radio.
 

Martaine2005

May 12, 2015
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The purpose of trying non rechargeables was to verify a battery issue.

Martin
 

David B

Dec 29, 2017
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The purpose of trying non rechargeables was to verify a battery issue.

Martin
Ok, I dont have any new alkaline batteries to try. I will see how the Instant batteries fare. I did not have any problems with the Uniross batteries in my Roberts radio that's what's making me question the Crypto radio. I will update when I have tried the Instant 2500 mAh batteries.
 

Audioguru

Sep 24, 2016
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Uniross sells cheap 1000, up to good 2700 AA rechargeable batteries. The number might be mAh.
The specs for the digital radio says it draws 500mA which is 2.5W. An ordinary radio draws much less current.
 

David B

Dec 29, 2017
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Uniross sells cheap 1000, up to good 2700 AA rechargeable batteries. The number might be mAh.
The specs for the digital radio says it draws 500mA which is 2.5W. An ordinary radio draws much less current.
So does this radio actually need this much power or is it simply an inefficient design I wonder?
 

Audioguru

Sep 24, 2016
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Maybe the digital circuit uses very old power-hungry TTL logic ICs.
 

crutschow

May 7, 2021
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The specs for the digital radio says it draws 500mA which is 2.5W.
Then AA's would only operate the radio for about 4 hours, at best.

Can you use your multimeter to measure the actual radio current (put multimeter in series with the battery connection to the radio).
 

David B

Dec 29, 2017
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Hello,

According to the specs, it also seems to be able to run on a 5V 500mA adapter (USB powered):
http://www.cryptoelectronics.com/pr...o-redi-db100-dab-fm-portable-radio-black.html

Bertus
You're right, it came with a cable that works with my Amazon Fire power plug but I prefer it to run off batteries when i'm painting and decorating so the radio is quick and easy to move around and no wires to get in the way. Also when working outside I don't have the option to plug it in. I may go back to my trusty old Roberts radio though the Crypto does have slightly better FM reception and also DAB.
 

bertus

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Hello,

Can you use a USB power bank?
There are some quite powerfull ones around.

Bertus
 

David B

Dec 29, 2017
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Then AA's would only operate the radio for about 4 hours, at best.

Can you use your multimeter to measure the actual radio current (put multimeter in series with the battery connection to the radio).
I don't know much about electronics so do I just lift out the positive end of one of the batteries with one probe on the positive end of the lifted battery and the other probe onto the connector (where the positive end of the lifted battery should go) with the meter on DCA (2A) with the black lead plugged into amp socket to read the current?
 

David B

Dec 29, 2017
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Uniross sells cheap 1000, up to good 2700 AA rechargeable batteries. The number might be mAh.
The specs for the digital radio says it draws 500mA which is 2.5W. An ordinary radio draws much less current.
The Uniross are Ultra 2100 mAh ni-mh . They seem like good batteries that I have used successfully in other devices admittedly they are getting quite old by now.
 

Audioguru

Sep 24, 2016
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Energizer AA Ni-MH batteries are 2300mAh and are made in Japan. Good quality.
Some Duracell AA Ni-MH batteries are 1300mAh and are made in China. Poor quality.
 

crutschow

May 7, 2021
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I don't know much about electronics so do I just lift out the positive end of one of the batteries with one probe on the positive end of the lifted battery and the other probe onto the connector (where the positive end of the lifted battery should go) with the meter on DCA (2A) with the black lead plugged into amp socket to read the current?
I think that's correct, but you seem to be talking about three leads which is confusing.
The red meter lead goes to the lifted battery terminal and the black lead goes to the battery connection on the radio.
What is the black lead you mention?
 

David B

Dec 29, 2017
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I think that's correct, but you seem to be talking about three leads which is confusing.
The red meter lead goes to the lifted battery terminal and the black lead goes to the battery connection on the radio.
What is the black lead you mention?
Sorry, the black lead is the one that goes into the multimeter which usually lives in the COM socket there are 2 other sockets to the left of the COM socket for measuring current one is (20A 15 sec max the other is for mA) im guessing I should plug the black lead into the mA socket as I am expecting a reading of less than 1A or should I put it in the 20A socket first to be on the safe side just in case I happen to get a reading greater than 1A that might damage the my multimeter? Also obviously the radio needs to be on when I test but should I keep the volume at the same loudness as I would normally listen to it?
 
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