Which Charging Method is Best?
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From: Robert Baer on 28 May 2010 05:12 ian field wrote: > "Robert Baer" <robertbaer(a)localnet.com> wrote in message > news:NeCdnRH9BLxRtGPWnZ2dnUVZ_vqdnZ2d(a)posted.localnet... >> Saturation wrote: >>> There are at 3 popular methods to recharge secondary batteries, and >>> variations of these: >>> >>> Constant current, or galvanostatic >>> >>> Pulse charging >>> >>> Burp or Reflex charging >>> >>> http://corsair.flugmodellbau.de/files/elektron/NASA-II.PDF >>> >>> I have always taken it for granted that its known which is better, but >>> its seems the optimal charging scheme isn't settled. If you built >>> your own, how did you determine the frequency and pulse widths in >>> positive, if you use pulse, and discharge, if you use reflex. Among >>> pulse chargers I've sampled the pulse widths, and frequency all vary. >>> >>> >>> http://www.powerdesignersusa.com/pdf/Tech%20Brief%20Negative%20Pulse%20Charging%20Techniques%20Myths%20&%20Facts%20-%20Final.pdf >>> >>> I am looking for experiences with charging methods readers find >>> optimal and which charger you use. Most commercial chargers are >>> either constant current or pulse. >>> >>> http://www.batterylifeplus.com/images/PDFs/Nguyen_2003.pdf >>> >>> The few that support reflex charging are often costly, in the $300-400 >>> range. >>> >>> http://www.amainhobbies.com/product_info.php/products_id/145655/n/Bantam-E-Station-BC8DP-NiCad-NiMH-LiIo-LiPo-LiFe-Pb-AC-DC-Balancing-Charger >>> >>> http://www.westbourne-model.co.uk/fusion-l702b-pro-emperor-dc-charger-10306-0.html >>> >>> >>> More on charging methods: >>> >>> http://www.mpoweruk.com/chargers.htm#pulse >> Pulse charging and similar variable current charging schemes are >> primarily to de-sulphate LEAD ACID batteries (secondary use is proposed to >> reduce or prevent sulphation). >> It really does not matter much what one does or how it is done (vary >> current in a lead acid battery), the net desired result is to break up >> sulphation and return the insoluble products back to usable lead >> components. >> If sulphation is excessive, up to 100V per cell may be needed to push >> 10mA in either direction and it could be weeks of application of >> AC-cycling-plus-charging-DC to get the current up to hundreds of milliamps >> of current. > > In the past I've livened up sulphated battery by connecting it to a bridge > rectifier inserted in the neutral lead of low power load (such as a 100W > 240V lightbulb) but since buying an Optimate battery conditioner, I've come > to the conclusion that if the conditioning charger can't get it started the > end result won't be worth the time and effort involved. > > Maybe so, but i used an AC-with-DC method similar to what i alluded to in re-juvenating a 1943 "drycharged" motorcycle battery that took the 100V mentioned. Took a month or so from start to end, but the result was over 200 AMP short circuit capability! Actual personal set-up time and time to change setup each time as current increased was about an hour total, so actual effort was not much.
From: ian field on 28 May 2010 09:48
"Robert Baer" <robertbaer(a)localnet.com> wrote in message news:Gcqdna3DZalmFWLWnZ2dnUVZ_tWdnZ2d(a)posted.localnet... > ian field wrote: >> "Robert Baer" <robertbaer(a)localnet.com> wrote in message >> news:NeCdnRH9BLxRtGPWnZ2dnUVZ_vqdnZ2d(a)posted.localnet... >>> Saturation wrote: >>>> There are at 3 popular methods to recharge secondary batteries, and >>>> variations of these: >>>> >>>> Constant current, or galvanostatic >>>> >>>> Pulse charging >>>> >>>> Burp or Reflex charging >>>> >>>> http://corsair.flugmodellbau.de/files/elektron/NASA-II.PDF >>>> >>>> I have always taken it for granted that its known which is better, but >>>> its seems the optimal charging scheme isn't settled. If you built >>>> your own, how did you determine the frequency and pulse widths in >>>> positive, if you use pulse, and discharge, if you use reflex. Among >>>> pulse chargers I've sampled the pulse widths, and frequency all vary. >>>> >>>> >>>> http://www.powerdesignersusa.com/pdf/Tech%20Brief%20Negative%20Pulse%20Charging%20Techniques%20Myths%20&%20Facts%20-%20Final.pdf >>>> >>>> I am looking for experiences with charging methods readers find >>>> optimal and which charger you use. Most commercial chargers are >>>> either constant current or pulse. >>>> >>>> http://www.batterylifeplus.com/images/PDFs/Nguyen_2003.pdf >>>> >>>> The few that support reflex charging are often costly, in the $300-400 >>>> range. >>>> >>>> http://www.amainhobbies.com/product_info.php/products_id/145655/n/Bantam-E-Station-BC8DP-NiCad-NiMH-LiIo-LiPo-LiFe-Pb-AC-DC-Balancing-Charger >>>> >>>> http://www.westbourne-model.co.uk/fusion-l702b-pro-emperor-dc-charger-10306-0.html >>>> >>>> >>>> More on charging methods: >>>> >>>> http://www.mpoweruk.com/chargers.htm#pulse >>> Pulse charging and similar variable current charging schemes are >>> primarily to de-sulphate LEAD ACID batteries (secondary use is proposed >>> to reduce or prevent sulphation). >>> It really does not matter much what one does or how it is done (vary >>> current in a lead acid battery), the net desired result is to break up >>> sulphation and return the insoluble products back to usable lead >>> components. >>> If sulphation is excessive, up to 100V per cell may be needed to push >>> 10mA in either direction and it could be weeks of application of >>> AC-cycling-plus-charging-DC to get the current up to hundreds of >>> milliamps of current. >> >> In the past I've livened up sulphated battery by connecting it to a >> bridge rectifier inserted in the neutral lead of low power load (such as >> a 100W 240V lightbulb) but since buying an Optimate battery conditioner, >> I've come to the conclusion that if the conditioning charger can't get it >> started the end result won't be worth the time and effort involved. > Maybe so, but i used an AC-with-DC method similar to what i alluded to > in re-juvenating a 1943 "drycharged" motorcycle battery that took the 100V > mentioned. > Took a month or so from start to end, but the result was over 200 AMP > short circuit capability! > Actual personal set-up time and time to change setup each time as > current increased was about an hour total, so actual effort was not much. In the vast majority of cases that I've had to use such extremes to revive a lead acid battery, the recovered capacity has been well down on what's marked on the case - although some have recovered further with heavy charge/discharge cycling, others have let me down and left me stranded - costing me time effort and money! |