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05-04-2011, 02:35 PM   #31
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My charger is the BC-900, so I guess maybe I'm in good shape even with 500 or 800. I've used 200 quite a bit too, though, and have probably left them in more than 14 hours on more than one occasion. I suppose it's *possible* that's why I don't get the 1000 shots per charge you do.

05-04-2011, 11:27 PM - 1 Like   #32
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QuoteOriginally posted by Marc Sabatella Quote
My charger is the BC-900, so I guess maybe I'm in good shape even with 500 or 800. I've used 200 quite a bit too, though, and have probably left them in more than 14 hours on more than one occasion. I suppose it's *possible* that's why I don't get the 1000 shots per charge you do.
The LaCrosse BC-900 - other than the ones that melted - are very good chargers - basically discussed in the same breath as the Maha C9000.

I'm not too sure of the BC-900's end of charge detection strategy -
but just as an example the Maha C9000 - with eneloops actually stops its 1/2C charge at 1.47V (at round about the 2hour mark) - so that is actually voltage threshold detection - before the -dV (delta) is even reached - it then drops in to lower charge "top off" current of 100mA -

In that way it is kind to the battery because the voltage threshold detection of 1.47V is actually before the -dV signal - ie: before the battery reaches fully charged - so at least on an eneloop it is never overcharged - the charge capacity is about 90% at that point - then topping off at 100mA for about 2 hours "fills up" the battery to its full charge capacity.

Ha-ha! talk about RTFM -
I actually found this in the Maha C9000 pdf manual (download link)


some people read the last paragraph to get "slower charge is better" -
but seem to totally miss the box with the larger BOLD italicized print
saying rate below 0.33C is not recommended.

The much acclaimed LaCrosse BC-700 barely makes the 0.33C charge current and cannot do 1/2C so it is marginal for eneloops.

The LaCrosse BC-500 - max charge current is 500mA - this is 1/4C which by any maths is below 0.33C.
05-05-2011, 05:32 AM   #33
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QuoteOriginally posted by cadmus Quote
gp1806, OK thanks, 7 months is good.


By relying on solar power in Alaska the weather gods will punish me with nothing but rain (Holt 1877).
Yeah, the boat has a solar panel and if we have the misfortune of having to run the motor we might have some spare power. But I am a guest on this boat. The last thing I want to do is steal electrons from navigation and radio equipment. After I pay off my student loans and build my own boat, I will have a way to charge my toys, for now I can not rely on it. But I will look into this option for some of my field work this summer, any recommendations on brands?
I found this today. I don't own it.
Newegg.com - Sunforce 50022 5 Watt Solar Battery Charger
Code is EMCKEKE48 , you need to have an account.

It would work with this charger. I do own this charger. Works very well. Charges each battery individually. Charger will take 12v DC as well as 120v AC.
Amazon.com: Duracell Mobile Charger with 4 AA Rechargeable NiMH Batteries, CEF23AU: Electronics
05-05-2011, 05:47 AM   #34
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QuoteOriginally posted by gp1806 Quote
I found this today. I don't own it.
Newegg.com - Sunforce 50022 5 Watt Solar Battery Charger....
Thanks, someday I will look into buying one, for environmental reasons. Looks like a good idea if car camping or doing research where I am in one place. I have read several forums in months past on the topic. There may be more but I found these
https://www.pentaxforums.com/forums/pentax-camera-field-accessories/139901-solar-charger.html
https://www.pentaxforums.com/forums/pentax-camera-field-accessories/51813-sol...r-options.html
https://www.pentaxforums.com/forums/pentax-dslr-discussion/17668-solar-power;...ra-owners.html
Unfortunately this and most my trips require that I carry less stuff so it will always be nice to just pack more alkalines or lithiums.

QuoteOriginally posted by gp1806 Quote
...Charger will take 12v DC as well as 120v AC....
Yeah, that is handy. My only complaint with the LaCrosse I bought is it doesn't have this feature (12v car plug). So I bought a DC-to-AC converter. That just seams silly, going from dc to ac to dc to chemical... lots of energy loss.


Last edited by cadmus; 05-06-2011 at 05:45 AM.
05-05-2011, 07:25 PM   #35
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QuoteOriginally posted by cadmus Quote
Unfortunately this and most my trips require that I carry less stuff so it will always be nice to just pack more alkalines or lithiums.


Yeah, that is handy. My only complaint with the LaCrosse I bought is it doesn't have this feature. So I bought a DC-to-AC converter. That just seams silly, going from dc to ac to dc to chemical... lots of energy loss.
That Duracell charger only needs a cord to go from the cigar lighter on a car to the charger, less to carry as well as less energy loss.
05-29-2011, 05:35 AM   #36
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Stoichiometry of AAs to SD cards

Thanks for the above help.

Per our previous conversations I will have the following on my 3 week trip:
-4 LaCrosse 2400mah AAs (1 set)
-12 Eneloop AAs (3 sets)
-8 Energizer Ultimate Lithium Disposable AAs. (2 sets)
To power
-48 Gigs of SD Cards. (EDIT 5-31-11: Later in the thread I update this to 52gigs)
I am guessing memory is the limiting reagent right? By how much? If I need more batts I will buy alkalines in the fishing villages and save the big batts for the open ocean segments.


What is a better charge? A brand new factory charged Eneloop out of the box? Or a recharged Eneloop on my Charger? (I assume the setting on the LaCrosse BC-9009 that drains it and recharges it is the best to use?)

Last edited by cadmus; 05-31-2011 at 07:08 AM.
05-29-2011, 10:17 AM   #37
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QuoteOriginally posted by cadmus Quote
-4 LaCrosse 2400mah AAs (1 set)
-12 Eneloop AAs (3 sets)
-8 Energizer Ultimate Lithium Disposable AAs. (2 sets)
To power
-48 Gigs of SD Cards.
I am guessing memory is the limiting reagent right? By how much? If I need more batts I will buy alkalines in the fishing villages and save the big batts for the open ocean segments.
What is a better charge? A brand new factory charged Eneloop out of the box? Or a recharged Eneloop on my Charger? (I assume the setting on the LaCrosse BC-9009 that drains it and recharges it is the best to use?)
Last question first -
eneloops are only factory charged to about 80% capacity -
PLUS the shelf time (ie: time since charge) to self-discharge probably unknown -
vs. recent charge to (hopefully) 100%?

So to be explicit - for convenience one might use eneloops out of the pack -
but to have full potential** capacity they are normally given a charge before usage.

For the more sophisticated battery aficionados - actually do a break-in cycle - but there is debate whether it is worth doing such on eneloops, and it is very time consuming.

**full potential capacity - most NiMH rechargeable batteries (including eneloops) are said to only gain full capacity after a few (complete) cycles.

So if you actually have the time it might worth discharging the eneloops first before charge -
the standard discharge current is 0.2C - that is 400mA for eneloops -
this discharge time would be somewhere between 3-5 hours -
allow at least 1 hour rest for the batteries to cool down -
(or just discharge the other sets as the previous sets cool down) -
then put on full 1/2C charge (ie: at 1000mA=1A) this will take about 2 hours.
Potential total time per set = 8 hours;
total for 3 sets = 24hours - that is only if your are in attendance to do the change overs.

If you do the discharge out of the pack -
then please record the final capacity (in mAh) of each battery
(it's worth numbering each individual battery for identification)
- this is very useful information - for some of us.

Since you have a set of regular NiMH LaCrosse 2400mah AAs - that have faster self-discharge than eneloops - it would be logical to use those first in your K200D - then the eneloops and keep the lithium AA in reserve.

EDIT to ADD -
QuoteOriginally posted by Marc Sabatella Quote
Could be, but I'm also betting you don't really get 1000 shots out of Eneloops as often on the K100D as the K-x - I'm pretty sure the latter is more power efficient.
Marc is absolutely correct the K-x is a lot more efficient than the K100D.

The K100D is probably less efficient than your K200D (a later model) -

But FWIW and jFYI -
K100D - between shot counts 8,922 and 17,407 my highest shot count from a set of eneloops was 1,169 and my LOWEST shot count was 987 - I only had shot counts below 1,000 twice - the other was at 989 -
but then I am very "frugal" with my shooting on the K100D, hardly ever use flash - and like the K200D there is no live view or movies to waste battery.

Last edited by UnknownVT; 05-29-2011 at 11:15 AM.
05-31-2011, 07:07 AM   #38
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Good info. Thanks. When you say
QuoteOriginally posted by UnknownVT Quote
...allow at least 1 hour rest for the batteries to cool down -...
Are you saying the LaCrosse charger might drain them too fast? You would think they would have programed that into the discharge process. I have not used it much. I know there is a setting that will drain them and re-condition them. But i will do as you suggest. Stop the draining every now and then or use them on something like a flash light.



Also, I have an ebay addiction and now am up to 52 gigs of SD cards. Damn ebay.

05-31-2011, 09:47 AM   #39
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QuoteOriginally posted by cadmus Quote
Are you saying the LaCrosse charger might drain them too fast? You would think they would have programed that into the discharge process. I have not used it much. I know there is a setting that will drain them and re-condition them. But i will do as you suggest. Stop the draining every now and then or use them on something like a flash light.
Don't quite understand what you mean by the last sentence re: stop draining (highlighted in red).

Basically batteries use chemical process to produce electricity.

I have always read that a "rest" does them good, and when batteries are warmed/heated up - then it is always better to allow them to cool down (if possible).

On a discharge - this is the same as using the battery (draining them) and if ths is constant and over a period of time - will tend to warm up - the standard discharge rate of 0.2C for (eneloops = 400mA) is not a low current nearly 1/2A - this may warm up the batteries - hence the advice in allowing them to "rest" and cool down before charging them.

The 1 hour rest is merely a rule of thumb.

If you do not want to wait - then just charge (top up) the batteries out of the pack at the recommended 1/2C = 1000mA = 1A - hopefully this takes about 1/2 hour (guesstimate) - and you're done, no waiting for anything to cool down etc.

Last edited by UnknownVT; 05-31-2011 at 10:09 AM.
05-31-2011, 10:58 AM   #40
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QuoteOriginally posted by UnknownVT Quote
Don't quite understand what you mean by the last sentence re: stop draining (highlighted in red).
You said "...this discharge time would be somewhere between 3-5 hours -
allow at least 1 hour rest for the batteries to cool down -"
So i was saying I will either use the lacrosse drain but stop it every now and then and rest them as you suggested. Rest should have been used instead of the word stop. Or I will drain them slowly with an led flash light or something slow. but either way i will do as you said and rest them so they don't get hot.

The drain setting on the lacrosse discharges them too fast, huh? Good to know.
05-31-2011, 11:33 AM   #41
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QuoteOriginally posted by cadmus Quote
You said "...this discharge time would be somewhere between 3-5 hours -
allow at least 1 hour rest for the batteries to cool down -"
So i was saying I will either use the lacrosse drain but stop it every now and then and rest them as you suggested. Rest should have been used instead of the word stop. Or I will drain them slowly with an led flash light or something slow. but either way i will do as you said and rest them so they don't get hot.

The drain setting on the lacrosse discharges them too fast, huh? Good to know.
If you can set the discharge current to 0.2C - this is the standard discharge current - for the eneloop = 400mA.

It is not a low current - but it is not considered "too fast" - this is the industry standard discharge current for measuring capacity - and it is the current most recommended for discharge.
06-04-2011, 04:28 PM   #42
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Currently (pun) i am discharging at 103mA on my LaCrosse. That is because my preset charge rate is 200 and it discharges at half that. It is taking forever so i will boost it up to your recommendation.

I have the other 4 eneloops in my ham radio but it is not doing a great job of drawing them down.

When you say
QuoteOriginally posted by UnknownVT Quote
I have always read that a "rest" does them good, and when batteries are warmed/heated up - then it is always better to allow them to cool down (if possible).
what kind of temperature difference to room temperature are you talking about. something observable by the human touch or some very small difference? I.E. If i am running them down in a flashlight and feel no increase in temp is it safe to keep running them.
06-04-2011, 04:44 PM   #43
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QuoteOriginally posted by cadmus Quote
Currently (pun) i am discharging at 103mA on my LaCrosse. That is because my preset charge rate is 200 and it discharges at half that. It is taking forever so i will boost it up to your recommendation.
A good discharge current is 0.2C = 400mA for eneloops and will take about 3.8hours assuming the batteries are about 80% charged out of the pack

Do the maths - (remaining) capacity (mAh) divided by discharge current (mA) = discharge time (hours).

103mA discharge will take obviously about 4 times as long - so about 15+ hours -

They are your batteries, so it's your decision and your choice.

QuoteOriginally posted by cadmus Quote
I have the other 4 eneloops in my ham radio but it is not doing a great job of drawing them down.
Do you know what current the ham radio draws?
it could be as low as 100mA - so again 15+ hours to drain the batteries - why are you insisting on using other unknown devices to drain your batteries when the LaCrosse BC-9009 a $50 charger is designed to do that at settable currents.

One last time from me
0.2C is the recommended discharge current - an industry standard for measuring capacity - for eneloops this is 400mA.


QuoteOriginally posted by cadmus Quote
When you say
what kind of temperature difference to room temperature are you talking about. something observable by the human touch or some very small difference? I.E. If i am running them down in a flashlight and feel no increase in temp is it safe to keep running them.
I do not know what temperatures the batteries could reach when used - I have never measured.

Do you know what the current drain is from your LED flashlight - if it's about 400mA then you ought to be fine - except do NOT allow the voltage to drop below 0.9V - or the battery will be damaged.
I believe the BC-9009 automatically stops discharge when the voltage drops to 0.9V.

Batteries can be warm to touch -
But any time they are too hot to hold - it is too hot
and the battery is likely to be already damaged.

Any time a battery warms up it means there was heat dissipation due to the internal chemical reaction - so it is worthwhile allowing them a "rest" to cool down -

All I ever suggested was to discharge them and allow some time before charging them - since you have 3 sets - discharge each set in turn - and by the time the 3 rd set has discharge, it should be safe for the first set to be charged.

Last edited by UnknownVT; 06-04-2011 at 04:59 PM.
06-04-2011, 04:56 PM   #44
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UnknownVT, how do you respond so quick?

They are never getting warm. When discharging in the lacrosse and when in the ham radio and when in the flashlight they are always room temp.

I have messed with this thing (LaCrosse BC-9009 ) for some time and it refuses to discharge faster than 100mA. I will reread the manual.

I got 8 eneloops in little flashlights and 4 on the charger.

T minus 54h 01m 32s till the taxi picks me up for my trip.

Last edited by cadmus; 06-04-2011 at 05:07 PM.
06-04-2011, 05:12 PM   #45
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QuoteOriginally posted by cadmus Quote
I have messed with this thing (LaCrosse BC-9009 ) for some time and it refuses to discharge faster than 100mA. I will reread the manual.

T minus 54h 01m 32s till the taxi picks me up for my trip.
really?

I don't use or own the LaCrosse chargers - yet I manage to download the LaCrosse BC-9009 pdf manual and -

How to use discharge:


How to set discharge current:


If possible set discharge current = 400mA (may not be one of the preset currents).
(BUT don't actually charge at 800mA -
it's much better to charge at 1000mA for eneloops)

If not then I would choose the best recommended charge current of 1/2C = 1000mA for eneloops
and live with the fact you are discharging at 500mA - which hopefully take about 3-4 hours.

With so little time left - you better just get on it and stop asking questions -
unless you do not trust the information given

3 sets to discharge at 400mA = nearly 12 hours
then to charge each set in turn at 1000mA = 6 hours -
so the MINIMUM time you have to do all that is 18 hours with on the spot changeovers
- I would just get on with it.

Last edited by UnknownVT; 06-04-2011 at 05:36 PM.
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