From: SMS on
J�rgen Exner wrote:
> SMS wrote:
>> Thomas T. Veldhouse wrote:
>>> I prefer to carry an inverter for in-car charging [aka cigarette
>>> lighter adapter], which delivers a LOT more power, in excess of 60
>>> watts in my case.
>> The car outlet can supply about 120 watts in most cars, are you saying
>> the performance is better on the 401FS with an inverter and the AC
>> supply, than it is directly from the car with the DC cord?
>
> Well, both, the conversion to household power by the inverter and back to
> charging load by the charger involve losses. So it is certainly not more
> efficient.
> But who cares about those losses which are maybe a few watts total compared
> to the losses of the car engine which range in the many kW area. It's really
> negligable, something like burning an additional interior lamp or so.

No, that's not what I meant. Some chargers specify different charge
currents based on the power source, but I don't think that's possible
the the MH-C401FS. The 12V from a car is typically fused at 10A, so
there should be sufficient current for the same charge rate as on AC.

The Tenergy T60008 has an AC flip out plug built in, and chargers at
600mA from AC, 450mA from 12V (car), and 250mA/cell from 5V (USB). The
12V charging current is related to the DC-DC converter limitations in
efficiency, especially over such a wide range of voltage. At 5V/500mA
input from USB, once you buck-convert, you're limited to about 1000mA
total (250mA/cell).

In any case, it's not the losses from the extra conversion that are an
issue, it's carrying:

a) a car charger cord
b) a power inverter AND the wall power supply

Can you imagine anyone doing (b) with a cell phone?
From: Thomas T. Veldhouse on
ASAAR <caught(a)22.com> wrote:
> On Fri, 13 Jul 2007 07:53:16 -0700, SMS wrote:
>
>>>> Yes, this is true. There are some instances where the higher capacity
>>>> is more valuable than the low self-discharge.
>>>
>>> I suspect that the actual 'in use' difference between a fully charged
>>> 2700mAh NiMH battery and a fully charged Eneloop 2100mAh battery would
>>> be only a few pictures, and then only in those rare cases where one
>>> actually uses a battery to discharge in a single day. Over a couple of
>>> days the slow self-discharge rate of the Eneloop would probably level
>>> the playing field.
>>
>> Yes, maybe I should have said "rare instances" rather than "some instances."
>
> Cases where it's not so rare would be when used in portable audio
> equipment where speakers are used instead of earphones (radios, CD
> players, etc.), since it wouldn't be unusual at all to need to
> recharge the batteries every day or two, depending on volume and how
> many hours the devices are used per day. For external speedlights
> such as Nikon's SB-800, 2,700mAh batteries would be much preferred
> over Eneloops unless they're used for only a small number of shots.

Actually, I never take enough flash pictures to drain my Sanyo Eneloop
batteries, so I really have no need to put 2700mAh batteries in with high
self-discharge rates. The day may come when I do have a need to take a LOT of
flash shots [and I mean, it takes a LOT of shots to drain 2000mAh batteries]
and that day, I will just put in the higher capacity batteries [for teh day].

--
Thomas T. Veldhouse

We have more to fear from the bungling of the incompetent than from the
machinations of the wicked.

From: SMS on
Thomas T. Veldhouse wrote:
> SMS <scharf.steven(a)geemail.com> wrote:
>
>> Li-Ion has a higher energy density by weight. Plus you have to carry
>> less spares. Plus the charger is smaller and lighter.
>
> Why is the charger smaller and lighter?

a) The charge circuitry is less complex because the battery pack has a
lot of the circuitry inside.

b) No need for individual slots with space between them so the
temperature sensors for each cell can accurately measure each cell.

c) No need for an AC wall wart

I.e., the Canon BP-511 charger is 123g and 175cc, while the Sanyo
NC-MQH01U AA charger (which has a built in AC adapter) is 151g and 317 cc.

The MH-C9000 has a volume of 1060cc (including the AC adapter), and
weighs 475g (including the AC adapter).

You can find smaller AA chargers, but these will have external power
supplies. You can find smaller AA chargers with internal power supplies,
but these are not full-featured.

> Citation please.

All the information is at "http://batterydata.com" or just Google "nimh
versus li-ion" and it's the first entry.
From: ASAAR on
On Fri, 13 Jul 2007 18:41:11 GMT, Thomas T. Veldhouse wrote:

>> Cases where it's not so rare would be when used in portable audio
>> equipment where speakers are used instead of earphones (radios, CD
>> players, etc.), since it wouldn't be unusual at all to need to
>> recharge the batteries every day or two, depending on volume and how
>> many hours the devices are used per day. For external speedlights
>> such as Nikon's SB-800, 2,700mAh batteries would be much preferred
>> over Eneloops unless they're used for only a small number of shots.
>
> Actually, I never take enough flash pictures to drain my Sanyo Eneloop
> batteries, so I really have no need to put 2700mAh batteries in with high
> self-discharge rates. The day may come when I do have a need to take a LOT of
> flash shots [and I mean, it takes a LOT of shots to drain 2000mAh batteries]
> and that day, I will just put in the higher capacity batteries [for teh day].

I only needed really high capacity NiMH batteries for an
"assignment" (personal, no pay) about 14 months ago, where I used
an old SB-24 speedlight. But are you talking about using Eneloops
with a high power external flash, or for the much weaker flashes
built into most cameras? Eneloops are more than adequate for when
I've used my Fuji S5100 or Canon A620. In fact, for them I've never
needed more than alkaline batteries. But the SB-800 is the power
drainer in Nikon's line of SB-x00 flashes. The little SB-400 uses
only 2 AA cells and is rated at 210 full power flashes taken at 30
second intervals. The SB-600 and SB-800 use 4 AA cells, and the
manuals conveniently (for Eneloop comparisons) rated them using
2,000mAh NiMH cells, specifying 220 shots for the SB-600 and 150
shots for the higher power SB-800. It's not just that I might take
slightly more than 150 shots with the SB-800, but also that I might
want to replace the NiMH batteries early, as the recycle time
steadily climbs as they're used.

One interesting thing I just noticed in the SB-400 manual verifies
what some manufacturers have said, that lithium AA cells aren't to
be used in some of the older, less efficient P&S cameras because of
heat concerns. The SB-400 manual shows that lithium AA cells can
provide 250 full power flashes, more than the 210 alkalines are good
for. But notes that instead of waiting 30 seconds between flashes,
when using lithium batteries the delay between shots was 120
seconds. So not only are lithium batteries far better for use in
frigid weather (working at much lower temperatures than Li-Ion
batteries), they can also help to warm up the camera. <g>

From: ASAAR on
On Fri, 13 Jul 2007 12:04:25 -0700, SMS wrote:

> You can find smaller AA chargers, but these will have external power
> supplies. You can find smaller AA chargers with internal power supplies,
> but these are not full-featured.

And I have one of the *much* smaller AA/AAA chargers. If by
'full-featured' you mean battery rejuvenation ability, it doesn't
have that. But it's a 'smarter' charger than most 'smart' chargers,
since it's the one that has the ability to continue charging AA
cells that most other chargers reject after a brief initial battery
test. I have several other chargers that can rejuvenate batteries,
but they're far from being as portable, since I can easily fit two
of these little collapsible chargers in my shirt pocket. It was
such a nice, little charger that I bought a second one in case I
ever dropped it and lost it in the grass. <g> It charges any
number of cells, from 1 to 4, and its power supply is internal, so
it requires no cords or wall warts. Mr. T says that he pities the
fool that doesn't own one. :)