ptarmigan Posted February 23, 2010 Share #1 Posted February 23, 2010 Advertisement (gone after registration) Does anyone know how to do this if indeed it can be done, or how I can check the current condition of my batteries? I have a D2x charger that allows me to this for my D2x and I use rechargeable batteries for most things at home and my recharger also allows 're-conditionng'. Thanks in advance. Link to post Share on other sites More sharing options...
Advertisement Posted February 23, 2010 Posted February 23, 2010 Hi ptarmigan, Take a look here Discharge & recondition M8 batteries?. I'm sure you'll find what you were looking for!
marknorton Posted February 23, 2010 Share #2 Posted February 23, 2010 Li-Ion battery packs have circuits in them which are there to ensure safe operation of the battery - over current and over temperature protection - and to monitor the charge in and out, so called Coulomb counters. Measuring the battery pack voltage - such as you might do with a lead-acid battery in your car - is a rather unreliable measure of remaining battery capacity and the battery meter on a camera is not just a simple voltmeter measuring battery voltage. If you look at an M8/9 battery pack, you'll see 4 connections, one of which is not used on the charger. The third one (in addition to + and -) is used to sense excessive temperature during charging and the charger will shut down if the battery gets too hot. When the battery is in the camera, the 4th connection comes into play and the camera can query how much charge the battery thinks it has and use that as an input to the battery meter function. I do not know for sure whether this is a bi-directional interface, whether for example, the camera can update the battery with a "you thought this but were wrong" correction. I think it probably can because the experience is that letting the battery drain completely in the camera does re-sync it. When I've run an M8 from an external power supply, I've done it with the circuitry in place, the bench power supply effectively replacing the basic Li-Ion cell in the battery pack. In this situation, the camera gets confused because even though there is limitless capacity available from the bench power supply, the chip says "I'm empty" because more current (charge, strictly) has flowed out of the battery pack than into it and the camera shuts down. The Nikon chargers drain the battery right down to empty - a known state - and then update the battery with information on the battery as it charges. It's likely the information allows a plot of acccumulated charge over time or against output voltage on load and the benefit of recalibration is that it takes account of ageing effects in the battery - charge in is subsequently not available as charge out. To answer your question then, the only way we have of conditioning or recalibrating the battery is to let it discharge fully in the camera and then charge it in the Leica charger. The battery pack will then presumably get updated with the charging information to give the camera the best chance of accurately showing battery capacity. The question which I don't have an answer to is how well this process works when the battery packs age. Link to post Share on other sites More sharing options...
ptarmigan Posted February 23, 2010 Author Share #3 Posted February 23, 2010 Mark Thanks. Not quite right on the recharge/recondition of Li batteries though. My D2x charger allows me to 'rejuvenate' the batteries which takes ages which is also the case on my 'intelligent' rechargeable batteries charger/conditioner. The process starts with a full discharge and then various charge/discharge cycles until the optimal/maximum charge is attained. Obviously a straight discharge/recharge of the M8 battery won't achieve anything like this process or state of reconditioning. I just wondered if any of you clever lot out there had managed anything. More in hope than in expectation. Link to post Share on other sites More sharing options...
jaapv Posted February 23, 2010 Share #4 Posted February 23, 2010 In the M9 manual Leica recommends to run a discharge-recharge every 20- 30 cycles. Link to post Share on other sites More sharing options...
marknorton Posted February 23, 2010 Share #5 Posted February 23, 2010 Thanks. Not quite right on the recharge/recondition of Li batteries though. My D2x charger allows me to 'rejuvenate' the batteries which takes ages which is also the case on my 'intelligent' rechargeable batteries charger/conditioner. The process starts with a full discharge and then various charge/discharge cycles until the optimal/maximum charge is attained. I don't know which D2x charger you have but if it's like mine, MH-21, the calibration function is (to quote the instruction sheet) "to allow precise measurement of battery charge, ensuring that the battery level can be displayed accurately". No mention of reconditioning. So either you have a different charger or else a Nikon sales "executive" has been over-selling to you... Link to post Share on other sites More sharing options...
ptarmigan Posted February 23, 2010 Author Share #6 Posted February 23, 2010 I don't know which D2x charger you have but if it's like mine, MH-21, the calibration function is (to quote the instruction sheet) "to allow precise measurement of battery charge, ensuring that the battery level can be displayed accurately". No mention of reconditioning. So either you have a different charger or else a Nikon sales "executive" has been over-selling to you... I stand corrected, humbly....... . I have double checked and you are correct. It seems just to be my pukka recharger that offers this facility for AA and AAA batteries. I'll keep taking the tablets. Link to post Share on other sites More sharing options...
marknorton Posted February 23, 2010 Share #7 Posted February 23, 2010 Advertisement (gone after registration) In any event, it looks like letting the camera drain the battery down is the closest we have to recalibration. Link to post Share on other sites More sharing options...
menos I M6 Posted February 24, 2010 Share #8 Posted February 24, 2010 Mark, the Leica manual explains also, to have brand new batteries cycle 3 − 4 times through a complete run down and recharge to condition them for a longer battery life. I bought two new batteries recently and ran them through these cycles. What is the technical background for this (I ask, as you seem very technically educated on the matter) Thanks in advance ;-) Link to post Share on other sites More sharing options...
marknorton Posted February 24, 2010 Share #9 Posted February 24, 2010 I do not know for sure but the charge and discharge operations are both reversible chemical reactions involving the anode, cathode and the electrolyte they sit in. Cycling through the complete charge/discharge cycle (as distinct from partial charge and discharge) probably ensures the entire contents of the cell is in use and participating in the battery operation. Link to post Share on other sites More sharing options...
menos I M6 Posted February 24, 2010 Share #10 Posted February 24, 2010 Thanks Mark - always curious, how things work ;-) Link to post Share on other sites More sharing options...
okram Posted February 24, 2010 Share #11 Posted February 24, 2010 I believe that it is also recommended to leave emptied battery to rest for a couple of hours before charging. At least, this is recommended for MacBook pro Li Ion battery (5 Hours) after discharge to do the reconditioning. Link to post Share on other sites More sharing options...
menos I M6 Posted February 25, 2010 Share #12 Posted February 25, 2010 I believe that it is also recommended to leave emptied battery to rest for a couple of hours before charging.At least, this is recommended for MacBook pro Li Ion battery (5 Hours) after discharge to do the reconditioning. When I informed myself about the MBP battery conditioning (I a suffering from quick battery aging of an early 2008 Penryn with several batteries and low battery life), I understood Apple's advice for leaving the computer 5 hours alone after self shut down as necessary, to really run down the battery completely. Right after a self shutdown, the battery still has enough capacity, to keep the computer in standby, having still all data in the RAM, making a wakeup after power connection almost instantaneous. After you have left the computer for a few more hours without power connection, you indeed cannot do a quick wakeup. The computer does the same boot procedure with reading the ghosted RAM data from the hard drive as in a total power failure (like removing the battery completely without power connector). I recharge my batteries immediately after discharge, when I have a charger at hand. The batteries safety circuit should do it's duty regarding unwanted temperatures or battery conditions, diminishing battery life I suppose. Link to post Share on other sites More sharing options...
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