[NSRCA-discussion] 12X Failure

[Bob Richards]

John,
 
My Accucycle has always seemed to detect a peak reliably at less than C/1. However, I always have it connected directly to the pack instead of going through the transmitter charge connector (with its associated diode, etc.) Anyway, if it does "think" that it has detected a peak, it does not shut off but will simply start charging at the lower rate, which I usually have set for C/10. 
 
A "maintenance" charge on a lead acid battery is a completely different beast. It is simply a constant voltage charge at a lower voltage, such as 13.2v for a 12v battery. All charging for nicads should be constant current.
 
I have some old nicad packs for my cordless drills that will short internally if I don't keep them under a constant charge. I know I should replace them, but they work fine for what I need as long as I remember to plug them in after I am done.

Bob R.

--- On Tue, 11/3/09, John Pavlick <jpavlick at idseng.com> wrote:








I always thought that "peak" charging with a typical negative delta-V type charger was not the best way to terminate a charge cycle unless you were charging at at least 1C. Most chargers will "false peak" when they're charging a battery at a low rate (C/10). This depends on the battery of course but I've found it to be true for the most part. I have an old Alpha-4 that I use to maintain my Ni packs. Works great but they're a bit hard to find.
 
You even need to be careful when using a "slow" charger. From my experience, I've found it best to charge overnight for 12 - 14 hours with a constant current at C/10. Anything less than C/10 may not fully charge the pack even if you leave it on for the proper amount of time (eg. C/50 for at least 50 hours). A very low current "maintenance" charge is OK for a short time after you've fully charged the pack but I wouldn't leave one on it indefinitely. Lead Acid batteries seem to tolerate a "maintenance" charge but Ni packs don't seem to like it.
 
John Pavlick

--- On Tue, 11/3/09, Bob Richards <bob at toprudder.com> wrote:


From: Bob Richards <bob at toprudder.com>
Subject: Re: [NSRCA-discussion] 12X Failure
To: "General pattern discussion" <nsrca-discussion at lists.nsrca.org>
Date: Tuesday, November 3, 2009, 2:34 PM







Jim,
 
I have an Accucyle Elite that I use. I can set the charge current to anything I want, and typically I will set it for 100 - 150ma charge rate for my regular transmitter batteries, and have it switch over to a 50 or 60ma rate after the peak detect. I like doing that since it will detect a peak and tell me how much it put back into the pack, then continue with a slow charge to equalize the cells after that.
 
Bob R.


--- On Tue, 11/3/09, J N Hiller <jnhiller at earthlink.net> wrote:









Bob I tend to agree. 
Where can I get an adjustable non-peak detecting charger with a 110 - 120 vac input. I don't trust a peak detecting charger to fully charge / balance the battery, even on a C/10 charge rate.

Jim Hiller 
 
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