X50 / X51 Accessories - Axim X50 / X51 Accessory Discussions
Reply
 
LinkBack Thread Tools
Old 06-26-07, 03:37 PM   #1 (permalink)
L.P.
Aximsite Minor League
 
L.P.'s Avatar
 
Join Date: Jun 2005
Posts: 220
Location: Seattle, WA
PDA: X51V
iTrader Rating: (0)
Thanks: 0
Thanked 0 Times in 0 Posts
View MyPDA
What is the best way to rotate batteries
How do you rotate your batteries?

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?

What are peoples suggestions.
__________________
L.P.
X51V
L.P. is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

Sponsored Links

Old 06-26-07, 04:49 PM   #2 (permalink)
Zaniax
Aximsite Legend
 
Zaniax's Avatar
 
Join Date: Aug 2005
Posts: 15,595
Location: Goa, India
iTrader Rating: (1)
Awards Showcase
Aximsite Bronze Contributors: For Members that have donated more than $10 to the website - Issue reason: Donation was made Aximsite Silver Contributors: For Members that have donated more than $50 to the website - Issue reason: Contributor Aximsite Gold Contributors: For Members that have donated more than $100 to the website - Issue reason: Donated more than $100 to MobilitySite! Silver Poster: Members that have achieved 10,000 Posts - Issue reason: 10,000 post Aximsite Bronze Referrer: Users that have referred at least 2 members. - Issue reason: User referred 2+ new members Aximsite Contest Winner: Winners of a previous Aximsite Contest - Issue reason: Merger Contest #20 - Astraware winner Aximsite Active Silver Member: Given to all active members (3 years and over 1,500 posts) - Issue reason: Active member 
Total Awards: 7
Thanks: 9
Thanked 24 Times in 24 Posts
View MyPDA
There is a limit to the number of times that you can charge a battery.
I run my battery down to 0% because it actually means that there still is about 30% capacity left.
This is a design 'trick' to prevent data loss.
I found that info somewhere on the M$ pages.

... and I did some tests myself:
Originally Posted by Zaniax View Post
Got four X50v 1100mAh batteries, but found out that they only provide 550 - 750 mAh

.
Zaniax is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

Old 06-26-07, 06:07 PM   #3 (permalink)
cchiang12
Aximsite All Star
 
Join Date: Feb 2006
Posts: 529
iTrader Rating: (0)
Thanks: 0
Thanked 0 Times in 0 Posts
View MyPDA
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
cchiang12 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

Old 06-26-07, 06:09 PM   #4 (permalink)
ikehiker
Aximsite Hall of Fame
 
ikehiker's Avatar
 
Join Date: Nov 2003
Posts: 8,759
Location: ME, USA
iTrader Rating: (0)
Awards Showcase
Moderator Medal: Given to past and present Aximsite Moderators - Issue reason: Aximsite Moderator Poster of the Month: Given to members the best poster of the month. This does not mean the  Bronze Poster: Members that have achieved 5000 Posts - Issue reason: + 5,000 posts Aximsite Active Bronze Member: Given to all active members (1 year and over 750 posts) - Issue reason: At time of award, user has 8313 posts & 3yrs 9-months Aximsite Active Silver Member: Given to all active members (3 years and over 1,500 posts) - Issue reason: At time of award, user has 8313 posts & 3yrs 9-months 
Total Awards: 5
Thanks: 0
Thanked 32 Times in 30 Posts
View MyPDA
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
__________________
-Ike-
ikehiker is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

Old 06-26-07, 06:27 PM   #5 (permalink)
L.P.
Aximsite Minor League
 
L.P.'s Avatar
 
Join Date: Jun 2005
Posts: 220
Location: Seattle, WA
PDA: X51V
iTrader Rating: (0)
Thanks: 0
Thanked 0 Times in 0 Posts
View MyPDA
Originally Posted by ikehiker View Post
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?
__________________
L.P.
X51V
L.P. is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

Old 06-26-07, 07:02 PM   #6 (permalink)
L.P.
Aximsite Minor League
 
L.P.'s Avatar
 
Join Date: Jun 2005
Posts: 220
Location: Seattle, WA
PDA: X51V
iTrader Rating: (0)
Thanks: 0
Thanked 0 Times in 0 Posts
View MyPDA
Originally Posted by ikehiker View Post
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?
__________________
L.P.
X51V
L.P. is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

Old 06-26-07, 08:01 PM   #7 (permalink)
ikehiker
Aximsite Hall of Fame
 
ikehiker's Avatar
 
Join Date: Nov 2003
Posts: 8,759
Location: ME, USA
iTrader Rating: (0)
Awards Showcase
Moderator Medal: Given to past and present Aximsite Moderators - Issue reason: Aximsite Moderator Poster of the Month: Given to members the best poster of the month. This does not mean the  Bronze Poster: Members that have achieved 5000 Posts - Issue reason: + 5,000 posts Aximsite Active Bronze Member: Given to all active members (1 year and over 750 posts) - Issue reason: At time of award, user has 8313 posts & 3yrs 9-months Aximsite Active Silver Member: Given to all active members (3 years and over 1,500 posts) - Issue reason: At time of award, user has 8313 posts & 3yrs 9-months 
Total Awards: 5
Thanks: 0
Thanked 32 Times in 30 Posts
View MyPDA
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)
__________________
-Ike-
ikehiker is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

Old 06-26-07, 08:06 PM   #8 (permalink)
L.P.
Aximsite Minor League
 
L.P.'s Avatar
 
Join Date: Jun 2005
Posts: 220
Location: Seattle, WA
PDA: X51V
iTrader Rating: (0)
Thanks: 0
Thanked 0 Times in 0 Posts
View MyPDA
Thanks Ike.
__________________
L.P.
X51V
L.P. is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

Old 06-27-07, 08:26 PM   #9 (permalink)
Zaniax
Aximsite Legend
 
Zaniax's Avatar
 
Join Date: Aug 2005
Posts: 15,595
Location: Goa, India
iTrader Rating: (1)
Awards Showcase
Aximsite Bronze Contributors: For Members that have donated more than $10 to the website - Issue reason: Donation was made Aximsite Silver Contributors: For Members that have donated more than $50 to the website - Issue reason: Contributor Aximsite Gold Contributors: For Members that have donated more than $100 to the website - Issue reason: Donated more than $100 to MobilitySite! Silver Poster: Members that have achieved 10,000 Posts - Issue reason: 10,000 post Aximsite Bronze Referrer: Users that have referred at least 2 members. - Issue reason: User referred 2+ new members Aximsite Contest Winner: Winners of a previous Aximsite Contest - Issue reason: Merger Contest #20 - Astraware winner Aximsite Active Silver Member: Given to all active members (3 years and over 1,500 posts) - Issue reason: Active member 
Total Awards: 7
Thanks: 9
Thanked 24 Times in 24 Posts
View MyPDA
Originally Posted by ikehiker View Post
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 ?

.
Zaniax is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

Old 06-27-07, 09:58 PM   #10 (permalink)
ikehiker
Aximsite Hall of Fame
 
ikehiker's Avatar
 
Join Date: Nov 2003
Posts: 8,759
Location: ME, USA
iTrader Rating: (0)
Awards Showcase
Moderator Medal: Given to past and present Aximsite Moderators - Issue reason: Aximsite Moderator Poster of the Month: Given to members the best poster of the month. This does not mean the  Bronze Poster: Members that have achieved 5000 Posts - Issue reason: + 5,000 posts Aximsite Active Bronze Member: Given to all active members (1 year and over 750 posts) - Issue reason: At time of award, user has 8313 posts & 3yrs 9-months Aximsite Active Silver Member: Given to all active members (3 years and over 1,500 posts) - Issue reason: At time of award, user has 8313 posts & 3yrs 9-months 
Total Awards: 5
Thanks: 0
Thanked 32 Times in 30 Posts
View MyPDA
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.
__________________
-Ike-
ikehiker is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

Old 06-27-07, 10:53 PM   #11 (permalink)
paulcb
Aximsite All Star
 
Join Date: Nov 2005
Posts: 503
Location: perkasie, pa
PDA: Axim X51v
iTrader Rating: (0)
Thanks: 11
Thanked 1 Time in 1 Post
View MyPDA
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.
paulcb is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

Old 06-28-07, 12:27 AM   #12 (permalink)
L.P.
Aximsite Minor League
 
L.P.'s Avatar
 
Join Date: Jun 2005
Posts: 220
Location: Seattle, WA
PDA: X51V
iTrader Rating: (0)
Thanks: 0
Thanked 0 Times in 0 Posts
View MyPDA
Originally Posted by paulcb View Post
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.
__________________
L.P.
X51V
L.P. is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

Old 06-29-07, 03:58 AM   #13 (permalink)
Zaniax
Aximsite Legend
 
Zaniax's Avatar
 
Join Date: Aug 2005
Posts: 15,595
Location: Goa, India
iTrader Rating: (1)
Awards Showcase
Aximsite Bronze Contributors: For Members that have donated more than $10 to the website - Issue reason: Donation was made Aximsite Silver Contributors: For Members that have donated more than $50 to the website - Issue reason: Contributor Aximsite Gold Contributors: For Members that have donated more than $100 to the website - Issue reason: Donated more than $100 to MobilitySite!