I have read the "Everything you may need to know about the Lithium-ion Battery" tutorial by Frenchy/Andre. I have also read that batteries should be stored at 40C and that you should not run your batteries below 70%.
If I have 4 or more batteries what is the best way to rotate them?
There is a limit to the number of times that you can charge a battery.
I run my battery down to 0% because it actually means that there still is about 30% capacity left.
This is a design 'trick' to prevent data loss.
I found that info somewhere on the M$ pages.
... and I did some tests myself:
Originally Posted by Zaniax
Got four X50v 1100mAh batteries, but found out that they only provide 550 - 750 mAh
I just charge them when they are low.
Rotate them out when the main battery is low.
It's too much work to keep track... not sure if it will make a difference anyway
I read somewhere that the new types of batteries last longer when they are charged up... but
Actually, running it down to 0% (even if it means '30%') actually shortens the lifespan. Slight discharges do not 'count' the same as deep discharges in the lifespan of Li-ion.
Originally Posted by L.P.
read that batteries should be stored at 40C
You better go read again. 40ºC would be really bad for them
Actually, running it down to 0% (even if it means '30%') actually shortens the lifespan. Slight discharges do not 'count' the same as deep discharges in the lifespan of Li-ion.
You better go read again. 40ºC would be really bad for them
You are right about the temperature it should have said 0C from: How to prolong lithium-based batteries
just shows how easy it is for me to mess stuff up.
I do not think it is a lot of work to keep track of the batteries you use. What do you think of the tutorial suggesting a discharge recharge at +-30 cycles?
Actually, running it down to 0% (even if it means '30%') actually shortens the lifespan. Slight discharges do not 'count' the same as deep discharges in the lifespan of Li-ion.
Ikehiker, do you hike with your Axim and GPS? If so how long do you run your battery and how many do you rotate?
No, I haven't done any substantial hikes since I started using PPCs - some knee problems and too busy at work. I think the knee is OK now and I've taken an early retirement so I should have more time now. I actually have a Garmin eTrek that is more rugged and thus better for outdoor conditions, so I don't plan to use my Axim that way.
If I remember correctly, 0ºC is actually a little low for battery storage. Refrigeration temperatures (5ºC; 40ºF) with the battery at around 40% charge level is best for long term storage and is what I do with my extra Li-ion batteries. I rarely need my PPC for more than the time a single battery lasts so I just leave the spare in the frig. When I do need longer usage, I charge it fully and take it with me but always put the same one back in the frig when I'm back. Li-ion batteries typically have a life span of 2 to 3 years, but storing them at low temperatures should extend that a couple of years. If I'm still using the same device when the original battery gets weak, I plan to I start using the backup and buy a new one for storage (however, I've never kept any devices as primary long enough to follow this plan)
Actually, running it down to 0% (even if it means '30%') actually shortens the lifespan. Slight discharges do not 'count' the same as deep discharges in the lifespan of Li-ion.
Thanks, Ike - but I just wonder what he means with the parameter 1C, 2C, 3C here:
Can you help me out, please ?
Sorry, I have no idea what the 'C' stands for in this graph. Based on the legend:
Quote:
Figure 3: Longevity of lithium-ion as a function of charge and discharge rates.
A moderate charge and discharge puts less stress on the battery, resulting in a longer cycle life.
C must relate to how deep the discharge is in each cycle but I don't know what the unit of measure might be. In practical terms, it probably doesn't matter.
My rule of thumb: use the battery when you need it, put it on the charger whenever you can.
I believe 1C means to charge/discharge at 1amp for a 1000mah battery, 2amps for a 2000 mah battery, etc.. So what the graph means is that the slower you charge and discharge, the longer your battery will last.
In any case, as IkeHiker says "use the battery when you need it, put it on the charger whenever you can". That's some good, real world advice.
I believe 1C means to charge/discharge at 1amp for a 1000mah battery, 2amps for a 2000 mah battery, etc.. So what the graph means is that the slower you charge and discharge, the longer your battery will last.
In any case, as IkeHiker says "use the battery when you need it, put it on the charger whenever you can". That's some good, real world advice.
Great advice but my question has to do with the best way to rotate, use, store if you have 3 or 4 batteries. Is it better to store at 40% charge in the refrigerator and then charge them up the one or two times a month I may need to use more than one battery because I am not near a charge source or should I rotate the batteries is some way, say down to a 40% charge put in the fridge, pull one out of storage and then use it when at a location such as home, where I can put it on the cradle and charge and use it.
It seems I could get equal life out of the 4 batteries if I rotated them to minimize the charge discharge cycles each battery would go through.
I have also read that batteries should be stored at 40C and that you should not run your batteries below 70%. 
