|Memory effect? (and other stuff)|
Message #15 Posted by Vieira, Luiz C. (Brazil) on 17 Mar 2003, 11:23 a.m.,
in response to message #14 by Andreas Müller(GER)
thank you for the informations you posted. One more question: as seen in many previous posts, my concerns are mostly about battery life and, in other aspaect, battery leakage. What was the specified charging time for the former original 4.8V/1,200mAh batteries? If it is designed to charged in about 5 hours, then we have about 20%-figure charging current, say, considering fewer loss, more than 240mAmps, right?
If you are using the same circuit and if this circuit delivers the same 240mAmps fo the bateries, as you are using a 3,300 mAh batteries, charging time should increase to about 12 hours if you want to increase operation time. If you keep the same 5 hours charging time, you'll keep the same operation time (a bit more, as new batteries are more efficient and charging curent is lower than expected). Two questions:
1 - Did you change the charging circuit OR use an external charger?
2 - isn't it better allowing longer charging periods in higher capacity batteries so you'll have bigger operating time?
I based the second question in the fact that NiMH batteries operating below their nominal capacity do not suffer the same memory effect observed in NiCads when used this same way. Is it correct?
I know I've been a lot incisive and annoying in these concerns, and I did not find (yet) time and adequate equipment (load patterns, recorders, precision measurement instruments OR RS232/USB connectible data collectors and a good SW) to proceed with experiments. Norm, if you're also reading, that's why I did not answer to your specific requests for lab testings: personal inadequate "financial" (temporary, I hope) condition. I'm running for better days so I can seat in front of my analog and digital set (many of them I built, a few I bought) and proceed with the so demmanded experiments.
Thank you all for contributing with a subject I believe is very important and, in some aspects, crytical enough to cause "injuries" in our dearest handheld calculators. Leakage, dammaged batteries will surelly be avoided if used correctly.
I think as soon as we have some more experimental and brand-related material will be time to compile all of this and write a good, concise battery-related article.
Best regards, folks.
Luiz C. Vieira - Brazil