LiON battery recharging - what strategy should I use?

I just bought a new digi camera and a second battery pack. The
literature says the batteries are good for "300 cycles", FWIW.

Should I run the battery in the camera flat before I switch to the
second one or should I do a top-off charge on every pack when it's
been used for more than a few shots?

The camera gets used daily for a few shots but I do an outing that
runs a fully charged pack to zero only every coouple months. I like
to carry two packs because (a) I distrust rechargables having the
charge I think they should have and (b) on occasion I get sucked into
something on very short notice that needs a full battery, if not more.

I'm not going to get anal on this. A new battery pack is only about 30
bucks.

Thanks.





--
Al Dykes
News is something someone wants to suppress, everything else is advertising.
- Lord Northcliffe, publisher of the Daily Mail

Al Dykes writes:

> I just bought a new digi camera and a second battery pack. The
> literature says the batteries are good for "300 cycles", FWIW.
>
> Should I run the battery in the camera flat before I switch to the
> second one or should I do a top-off charge on every pack when it's
> been used for more than a few shots?
>
> The camera gets used daily for a few shots but I do an outing that
> runs a fully charged pack to zero only every coouple months. I like
> to carry two packs because (a) I distrust rechargables having the
> charge I think they should have and (b) on occasion I get sucked into
> something on very short notice that needs a full battery, if not more.

I have some of the same concerns. Supposedly Li-ion likes to be charged
frequently and fully, so it's fine (and perhaps best) to recharge a
partially-discharged battery as soon as you like.

And supposedly they last longer if you keep them cool and store them with
about a 50% charge, but it's a bit awkward to get them to exactly 50%.

As you say, they aren't that expensive, so it's not a big deal. My main
concern is that I don't want to run out of battery power when I'm right in the
middle of shooting, which could happen if a battery loses so much capacity
over time that it only lasts for a few dozen photos. My current strategy is
to just have extra batteries that are fully charged; it seems unlikely that
they'll all wear out simultaneously, so I hopefully will have at least one
fully charged, full capacity battery with me all the time.

I don't really understand why manufacturers love rechargeables so much.
What's wrong with two AA batteries?

"Mxsmanic" <mxsmanic@gmail.com> wrote in message
news:ie3184lsol1fe3uvsgvvtrn6bve5glpsrm@4ax.com...
> Al Dykes writes:
>
> I don't really understand why manufacturers love rechargeables so much.
> What's wrong with two AA batteries?
>

AA Alkalines don't have the deep cycle that cameras and other tech toys
require, but at $1 each x 4 (my camera uses) x 300 uses = $1,200
at is pretty expensive versus rechargables, mind you my last name isn't
DuraCell

On 18/07/2008 23:07 Dev/Null wrote:
> "Mxsmanic" <mxsmanic@gmail.com> wrote in message
> news:ie3184lsol1fe3uvsgvvtrn6bve5glpsrm@4ax.com...
>> Al Dykes writes:
>>
>> I don't really understand why manufacturers love rechargeables so much.
>> What's wrong with two AA batteries?
>>
>
> AA Alkalines don't have the deep cycle that cameras and other tech toys
> require, but at $1 each x 4 (my camera uses) x 300 uses = $1,200
> at is pretty expensive versus rechargables, mind you my last name isn't
> DuraCell


Alkaline cells have relatively high internal electrical resistance
and can't efficiently deliver energy at the high currents demanded by
digital cameras. That's why they get very warm in digital cameras.
Rechargeable batteries don't have that limitation.
Also Li-Ion batteries store more energy for their physical volume
than alkalines.

On Fri, 18 Jul 2008 23:55:29 +1000, Bob Parker wrote:

> Alkaline cells have relatively high internal electrical resistance
> and can't efficiently deliver energy at the high currents demanded by
> digital cameras. That's why they get very warm in digital cameras.
> Rechargeable batteries don't have that limitation.

The relatively high resistance is only a problem with cameras that
have very high current demands. That was generally the case more
than 4 years ago when a set of alkalines might have lasted for only
a couple of dozen shots. In today's cameras, hundreds of shots
using full power flashes and with the LCD display on (the CIPA
procedure) to well over 1,000 shots using few flashes per set of
alkaline AA batteries isn't uncommon.


> Also Li-Ion batteries store more energy for their physical volume
> than alkalines.

That may have been true several years ago, but in that time my
NiMH AA cells have had an increase in capacity from about 1,000mAh
to today's 2,700mAh. FWIW, I was quite surprised a week or two ago
when I found that instead of using relatively large proprietary
rechargeable batteries, many of today's portable phones from
Panasonic and other companies are now being supplied with only two
AAA NiMH cells, and getting very good talk and standby time from
them. It's still true though that for the same physical volume,
Li-Ion batteries weigh much less than alkaline or NiMH cells.

Mxsmanic wrote:

> I don't really understand why manufacturers love rechargeables so much.
> What's wrong with two AA batteries?

As far as Li-Ion there are a lot of reasons:

1. Much lower self-discharge rate (except for newer Hybrio and eneloop
NiMH cells, which trade low self-discharge for lower capacity)

2. More charge/discharge cycles

3. Usage pattern and charge regimen is better suited to digital cameras
(and other devices where the usual pattern is partial discharge/full charge)

4. Self-Discharge rate is constant during the life of the battery (NiMH
batteries steadily increase in self-discharge over the life of the battery)

5. Greater energy density by weight

6. Greater energy density by volume (AA batteries are not practical for
sub-compact and ultra-compact cameras because of size, and AAA batteries
are not practical because of capacity)

7. Greater number of shots per WH

8. Faster shot to shot times, especially when using flash

9. More convenient to swap and charge than AA cells (no fumbling with
multiple cells, and keeping track of which battery is in which set)

10. Far better cold weather performance

11. Far better performance at high temperatures

12. Devices using Li-Ion batteries are more reliable than devices using
AA batteries (unlikely to have a battery door flip open and have the
batteries scatter all over)

13. Li-Ion batteries can be left in devices that are not used for long
periods of time

14. Li-Ion batteries have protection circuitry built into the pack and
do not rely on the charger for this protection

15. Accurate charge level gauge is included in most Li-Ion powered
cameras, but is not possible in NiMH powered cameras (low-battery
indicator only)

16. Li-Ion batteries do not suffer from polarity reversal

17. Li-Ion batteries do not suffer from the "dud" cell problem

18. No need to "Battery Match" cells of similar capacity

19. Rechargeable battery and charger come with the camera, versus buying
a charger and batteries for an AA powered camera

20. Smaller and lighter chargers


Steve
"http://batterydata.com/"
Earth's Independent and Authoritative Source for Digital Camera Battery
Information

On Fri, 18 Jul 2008 13:34:26 -0700, SMS <scharf.steven@geemail.com>
wrote:

>Mxsmanic wrote:
>
>> I don't really understand why manufacturers love rechargeables so much.
>> What's wrong with two AA batteries?
>
>As far as Li-Ion there are a lot of reasons:
>
>1. Much lower self-discharge rate (except for newer Hybrio and eneloop
>NiMH cells, which trade low self-discharge for lower capacity)

So a Li-Ion battery has a lower self discharge rate than an AA
alkaline? I don't think so.

In article <j87gk.13512$cW3.7832@nlpi064.nbdc.sbc.com>, SMS
<scharf.steven@geemail.com> wrote:

> Mxsmanic wrote:
>
> > I don't really understand why manufacturers love rechargeables so much.
> > What's wrong with two AA batteries?
>
> As far as Li-Ion there are a lot of reasons:

here we go again...

> 2. More charge/discharge cycles

lion degrades whether you use it or not. after a year or two, it
doesn't matter whether you used 300 cycles or 3 cycles, the lion
battery will have lower capacity.
>
> 3. Usage pattern and charge regimen is better suited to digital cameras
> (and other devices where the usual pattern is partial discharge/full charge)

depends on one's usage patterns. some people shoot daily, others shoot
sporadically every month or two.

> 5. Greater energy density by weight

more expensive too.

> 7. Greater number of shots per WH

not necessarily

> 8. Faster shot to shot times, especially when using flash

which flash uses lion?

> 9. More convenient to swap and charge than AA cells (no fumbling with
> multiple cells, and keeping track of which battery is in which set)

that's why they make battery carriers.

> 12. Devices using Li-Ion batteries are more reliable than devices using
> AA batteries (unlikely to have a battery door flip open and have the
> batteries scatter all over)

nonsense. whether the battery door is flimsy or not has *nothing* to
do with the battery technology.
>
> 13. Li-Ion batteries can be left in devices that are not used for long
> periods of time

so can nimh, particularly eneloops. heck i've left alkaline in some
devices for a long time.

> 14. Li-Ion batteries have protection circuitry built into the pack and
> do not rely on the charger for this protection

as long as there's protection circuitry, what difference does it make?
also, lion batts can explode, while nimh will just overheat, or worst
case, melt.

> 15. Accurate charge level gauge is included in most Li-Ion powered
> cameras, but is not possible in NiMH powered cameras (low-battery
> indicator only)

it can be reasonably accurate.

> 16. Li-Ion batteries do not suffer from polarity reversal
>
> 17. Li-Ion batteries do not suffer from the "dud" cell problem

oh yes they do.

> 18. No need to "Battery Match" cells of similar capacity

that's because lion batteries are always in a pack, never single cells.
that has nothing to do with it being lion.

> 19. Rechargeable battery and charger come with the camera, versus buying
> a charger and batteries for an AA powered camera

nimh chargers come with various products too, although generally very
basic ones.
>
> 20. Smaller and lighter chargers

depends on the charger.

snip

>> > I don't really understand why manufacturers love rechargeables so much.
>> > What's wrong with two AA batteries?
>>
>> As far as Li-Ion there are a lot of reasons:
>
>here we go again...

He's just proven his bias for Li-Ion once again. He was so eager to
post the attributes of Li-Ion that he forgot to notice that he was
responding to a comparison of AA alkaline's. With AA alkaline's in
mind most of his attributes do not apply or are wrong

>> 2. More charge/discharge cycles

Snip

Al Dykes wrote:
> I just bought a new digi camera and a second battery pack. The
> literature says the batteries are good for "300 cycles", FWIW.
>
> Should I run the battery in the camera flat before I switch to the
> second one or should I do a top-off charge on every pack when it's
> been used for more than a few shots?
>
> The camera gets used daily for a few shots but I do an outing that
> runs a fully charged pack to zero only every coouple months. I like
> to carry two packs because (a) I distrust rechargables having the
> charge I think they should have and (b) on occasion I get sucked into
> something on very short notice that needs a full battery, if not more.
>
> I'm not going to get anal on this. A new battery pack is only about 30
> bucks.
>
> Thanks.
>
>
>
>
>
OK. A few facts.
Lithium Ion rechargeables have a basic life of 3 years in normal use.
Charge cycles don't make a lot of difference as most devices that use
them insist you recharge when the power drops to about 20%, so you can
recharge daily, if you want to.
If you will multiply the number of shots you get when you run the
battery down to the point where it indicates it needs recharging, by the
number of 'cycles' (300), I suspect that will exceed the number of
pictures you will likely do with that camera. Given that you have two
batteries, I don't think you really need to worry about this issue, but
you should be aware that BOTH the batteries, regardless of use, will
probably lose more than 50% of their charge capacity over 3 years.