Eneloops went negative
Turned on the ancient Sony FM portable this AM and noticed
that the red tuning LED was not coming on even though the signal seemed ok. It runs on 4 rechargeables, currently a set of 2008 Eneloops which were recharged about a week ago, but have only been in use in the radio for couple of months (normally used in a Ricoh Caplio camera) Out of interest I took them out and measured the volts. Out of the 4 batteries, two (inline) measured 1.29 volts while the other two measured MINUS 0.094 volts !!??. What's going on ?. I put them back in the 7-day-shop intelligent charger and they registered as empty on the LCD screen but after only a minute they were reading 1.29 volts and after 15 minutes 1.34 volts by which time the lcd screen suggested they were half charged. What's going on ?. Is the charger at fault, or is the radio causing this ?. For some time I have noticed a strange, faint drum-beating sound from the radio even when it is switched off. Andrew |
Eneloops went negative
Andrew wrote:
Out of the 4 batteries, two (inline) measured 1.29 volts while the other two measured MINUS 0.094 volts !!??. What's going on ?. over-discharge https://en.wikipedia.org/wiki/Nickel%E2%80%93metal_hydride_battery#Over-discharge |
Eneloops went negative
On 02/02/2020 09:43, Andrew wrote:
Turned on the ancient Sony FM portable this AM and noticed that the red tuning LED was not coming on even though the signal seemed ok. It runs on 4 rechargeables, currently a set of 2008 Eneloops which were recharged about a week ago, but have only been in use in the radio for couple of months (normally used in a Ricoh Caplio camera) Out of interest I took them out and measured the volts. Out of the 4 batteries, two (inline) measured 1.29 volts while the other two measured MINUS 0.094 volts !!??. What's going on ?. I put them back in the 7-day-shop intelligent charger and they registered as empty on the LCD screen but after only a minute they were reading 1.29 volts and after 15 minutes 1.34 volts by which time the lcd screen suggested they were half charged. What's going on ?. Is the charger at fault, or is the radio causing this ?. For some time I have noticed a strange, faint drum-beating sound from the radio even when it is switched off. Andrew driven into reverse charge by the better cells Not unusual -- I would rather have questions that cannot be answered... ....than to have answers that cannot be questioned Richard Feynman |
Eneloops went negative
The issue is common and is why some batteries die. When batteries go down,
some will discharge faster than others. This means that in effect if the device is capable of running on a lower voltage. all the current supplied by the still good batteries will go through the discharged ones, backwards, in effect reverse charging them. Depending on the technology of the battery, it will either ruin them, or just hasten their final demise. Sadly I've never found an answer to this series battery dilemma and I tend to try to batch test them and move all the ones that discharge first into some device with low current needs, and try to pair up matching ones. Its a pain but part of life these days. This is also why I hate chargers that charge batteries in series as well, since this cooks some batteries while the others are still charging. Many portable phones etc, do this for cheapness and I'm always finding them clapped out and hot. Brian -- ----- -- This newsgroup posting comes to you directly from... The Sofa of Brian Gaff... Blind user, so no pictures please Note this Signature is meaningless.! "Andrew" wrote in message ... Turned on the ancient Sony FM portable this AM and noticed that the red tuning LED was not coming on even though the signal seemed ok. It runs on 4 rechargeables, currently a set of 2008 Eneloops which were recharged about a week ago, but have only been in use in the radio for couple of months (normally used in a Ricoh Caplio camera) Out of interest I took them out and measured the volts. Out of the 4 batteries, two (inline) measured 1.29 volts while the other two measured MINUS 0.094 volts !!??. What's going on ?. I put them back in the 7-day-shop intelligent charger and they registered as empty on the LCD screen but after only a minute they were reading 1.29 volts and after 15 minutes 1.34 volts by which time the lcd screen suggested they were half charged. What's going on ?. Is the charger at fault, or is the radio causing this ?. For some time I have noticed a strange, faint drum-beating sound from the radio even when it is switched off. Andrew |
Eneloops went negative
On 02/02/2020 09:55, The Natural Philosopher wrote:
On 02/02/2020 09:43, Andrew wrote: Andrew driven into reverse charge by the better cells Not unusual +1 |
Eneloops went negative
On 02/02/2020 09:55, The Natural Philosopher wrote:
On 02/02/2020 09:43, Andrew wrote: Turned on the ancient Sony FM portable this AM and noticed that the red tuning LED was not coming on even though the signal seemed ok. It runs on 4 rechargeables, currently a set of 2008 Eneloops which were recharged about a week ago, but have only been in use in the radio for couple of months (normally used in a Ricoh Caplio camera) Out of interest I took them out and measured the volts. Out of the 4 batteries, two (inline) measured 1.29 volts while the other two measured MINUS 0.094 volts !!??. What's going on ?. I put them back in the 7-day-shop intelligent charger and they registered as empty on the LCD screen but after only a minute they were reading 1.29 volts and after 15 minutes 1.34 volts by which time the lcd screen suggested they were half charged. What's going on ?. Is the charger at fault, or is the radio causing this ?. For some time I have noticed a strange, faint drum-beating sound from the radio even when it is switched off. Andrew driven into reverse charge by the better cells Not unusual It was a set of four that have had similar usage. |
Eneloops went negative
On 02/02/2020 13:34, Andrew wrote:
On 02/02/2020 09:55, The Natural Philosopher wrote: On 02/02/2020 09:43, Andrew wrote: Turned on the ancient Sony FM portable this AM and noticed that the red tuning LED was not coming on even though the signal seemed ok. It runs on 4 rechargeables, currently a set of 2008 Eneloops which were recharged about a week ago, but have only been in use in the radio for couple of months (normally used in a Ricoh Caplio camera) Out of interest I took them out and measured the volts. Out of the 4 batteries, two (inline) measured 1.29 volts while the other two measured MINUS 0.094 volts !!??. What's going on ?. I put them back in the 7-day-shop intelligent charger and they registered as empty on the LCD screen but after only a minute they were reading 1.29 volts and after 15 minutes 1.34 volts by which time the lcd screen suggested they were half charged. What's going on ?. Is the charger at fault, or is the radio causing this ?. For some time I have noticed a strange, faint drum-beating sound from the radio even when it is switched off. Andrew driven into reverse charge by the better cells Not unusual It was a set of four that have had similar usage. so what? some are always better than others -- It is hard to imagine a more stupid decision or more dangerous way of making decisions than by putting those decisions in the hands of people who pay no price for being wrong. Thomas Sowell |
Eneloops went negative
Brian Gaff (Sofa 2) wrote
No idea what the drumming sound is, a spider trying to attract a mate perhaps? No spiders do that. More likely one got infected with the heavy metal **** he played on it. "The Natural Philosopher" wrote in message ... On 02/02/2020 09:43, Andrew wrote: Turned on the ancient Sony FM portable this AM and noticed that the red tuning LED was not coming on even though the signal seemed ok. It runs on 4 rechargeables, currently a set of 2008 Eneloops which were recharged about a week ago, but have only been in use in the radio for couple of months (normally used in a Ricoh Caplio camera) Out of interest I took them out and measured the volts. Out of the 4 batteries, two (inline) measured 1.29 volts while the other two measured MINUS 0.094 volts !!??. What's going on ?. I put them back in the 7-day-shop intelligent charger and they registered as empty on the LCD screen but after only a minute they were reading 1.29 volts and after 15 minutes 1.34 volts by which time the lcd screen suggested they were half charged. What's going on ?. Is the charger at fault, or is the radio causing this ?. For some time I have noticed a strange, faint drum-beating sound from the radio even when it is switched off. Andrew driven into reverse charge by the better cells Not unusual -- I would rather have questions that cannot be answered... ...than to have answers that cannot be questioned Richard Feynman |
Eneloops went negative
Brian Gaff (Sofa 2) wrote:
No idea what the drumming sound is, a spider trying to attract a mate perhaps? Brian Might it be the LF instability that used to be commonly called motor-boating? -- Roger Hayter |
UNBELIEVABLE: It's 02:28 am in Australia and the Senile Ozzietard is out of Bed and TROLLING, already!!!! LOL
On Mon, 3 Feb 2020 02:28:02 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again: FLUSH the senile sick idiot's latest troll**** 02:28??? LOL Is your unbearable LONELINESS not letting you sleep in again, you cantankerous senile pest? GOOD! -- Website (from 2007) dedicated to the 85-year-old trolling senile cretin from Oz: https://www.pcreview.co.uk/threads/r...d-faq.2973853/ |
Eneloops went negative
On Sunday, 2 February 2020 16:45:42 UTC, Roger Hayter wrote:
Brian Gaff (Sofa 2) wrote: No idea what the drumming sound is, a spider trying to attract a mate perhaps? Brian Might it be the LF instability that used to be commonly called motor-boating? ....caused by a bad cap. NT |
Eneloops went negative
On 02/02/2020 10:27, Andrew wrote:
On 02/02/2020 09:54, Andy Burns wrote: Andrew wrote: Out of the 4 batteries, two (inline) measured 1.29 volts while the other two measured MINUS 0.094 volts !!??. What's going on ?. over-discharge https://en.wikipedia.org/wiki/Nickel%E2%80%93metal_hydride_battery#Over-discharge Ok, that means the Radio is at fault then, hence the odd faint drumming noise it makes when it is 'off'. Time to visit JL or similar for a replacement radio that runs on mains (as this one did until I dropped it while doing some outside DIY and it landed on a corner whereby the impact broke the internal mains transformer away from the circuit board). You have a device which has easily accessible DC power inputs, and is capable of handing a wide range of DC inputs (4 to 6v). This is the same range of voltage that 90% of mobile chargers spit out. USB chargers spit out 5V and your average Nokia/Sony Ericsson proprietary charger spits out somewhere betweeen 4.5 and 5.7v. Either find an old charger, a mains USB charger+a 2 or 3m USB cable cut off the old phone end connector, verify the polarity and solder the wires onto the battery terminals. Cut a notch in the battery cover to let the wire in - done. If you want to get clever, either make 2 dummy batteries out of 10mm dowelling and terminate the wires to screws, mark the + and - terminals. or cleaner still - buy a 2.1mm panel mounting dc barrel connector and matching cable connector. Open the radio, connect the tip of the connector to the radio and battery +ve terminal, connect the sleeve terminal to the radio -ve wire, and the switch terminal to the battery -ve. Verify that inserting the (dead) plug into the socket turns the radio off when running off batteries, then wire the plug to the charger, and mount the socket in a freshly drilled hole in the case. For the record - I've had a Sony Ericsson CST-60 charger powering an Ikea Molgan PIR light (3xAAA) glued on top as a landing nightlight for years... |
Eneloops went negative
On 02/02/2020 13:34, Andrew wrote:
On 02/02/2020 09:55, The Natural Philosopher wrote: On 02/02/2020 09:43, Andrew wrote: Turned on the ancient Sony FM portable this AM and noticed that the red tuning LED was not coming on even though the signal seemed ok. It runs on 4 rechargeables, currently a set of 2008 Eneloops which were recharged about a week ago, but have only been in use in the radio for couple of months (normally used in a Ricoh Caplio camera) Out of interest I took them out and measured the volts. Out of the 4 batteries, two (inline) measured 1.29 volts while the other two measured MINUS 0.094 volts !!??. What's going on ?. For some time I have noticed a strange, faint drum-beating sound from the radio even when it is switched off. Elves inside trying to get out. driven into reverse charge by the better cells Not unusual It was a set of four that have had similar usage. In any set of four there is always a weakest cell. The first one to fail will have current flowing through it driven by the remaining good ones. Leakage is often a problem if the cell is abused in this way for long. Devices that will tolerate a wide range of input voltages tend to cause this sort of problem most often. Many higher current devices have an absolute minimum voltage where they will work and shut down gracefully to avoid driving any weaker cells into reverse bias. LCD based kit tends to self limit when you can no longer read the display on it. -- Regards, Martin Brown |
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