I find the best flash batteries these days to be Sanyo Eneloop. If I'm
shooting an event where I need fast recycling I will use a high voltage
battery pack. Other than that I'll use the Eneloops. You can find much
more capacity in other NiMH batteries (I hear they're up to 2800 mah
now) but two sets of 2000 mah Eneloops is more than enough for any
shooting situation I've ever seen and they can sit on the shelf for
months (maybe even a year) without worrying about whether they still
have a charge or not.
Chuck Norcutt
Tim Hughes wrote:
> They may be somewhat similar to these Chinese CR-V3 rechargeable batteries :
> http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=1084
>>From the vague specs for these, these might well be LiIon rather than
>>LiFePO4. They claim they
> work well with the small flashes in the digital cameras, but who knows what
> that means in max
> current terms.
>
> Here is an actual vendor but specs are worthless:
> http://www.globalsources.com/gsol/I/Camera-battery/p/sm/1006279291.htm
> These vendors do seem to say though, "protection circuits built in" or
> similar.
>
> The rechargeable versions of the smaller CR123A camera batteries, seem most
> often to be LiFePO4,
> sometimes with added electronics protection/voltage reduction. Those have
> current ratings of
> under 1A.
>
> Steve's Digcams lists a variety of retail sources for these CRV-3 some marked
> Digital camera
> battery:
> http://www.steves-digicams.com/nimh_batteries.html
> They point out the different chargers and cells are incompatible, which could
> mean different
> chemistry depending on vendor. A lot of these are rated at 1.3Ah-1.4Ah. If
> you assume they can
> only do 1-2C max, a fairly typical rating for small cells, this means 1.4A to
> maybe 2.8A with
> luck, but if they have active current limit then an alkaline might well do
> better.
>
> Retail specs list voltage as: 3V for some of these cells,3.1V, 3.6V and 2.4V
> for the NiMH
> versions. The NiMh will drop to 2.2V to extract reasonable capacity, so
> clearly these digi
> cameras are not too picky!
>
> Tim Hughes
>
>
> --- John Hudson <OM4T@xxxxxxxxxxx> wrote:
>
>> The re-chargeable CR-V3s are labelled "Digital Rechargeable". There is no
>> manufacture's name specified nor a place of manufacture.
>>
>> The warning label on the outer wrapping reads, in part "........Keep the
>> battery in dry and cool environment. Keep battery out of children [sic]
>> reach."
>>
>> Draw your own conclusions as to where these things originated.
>>
>> jh
>>
>>
>>
>>
>> ----- Original Message -----
>> From: "Chuck Norcutt" <chucknorcutt@xxxxxxxxxxxxxxxx>
>> To: <olympus@xxxxxxxxxx>
>> Sent: Saturday, April 26, 2008 8:50 PM
>> Subject: [OM] Re: rechargable lithium ion batteries
>>
>>
>>> Probably all you have to do is check the specs for current draw on the
>>> manufacturer's web page and compare to alkaline.
>>>
>>> Chuck Norcutt
>>>
>>> John Hudson wrote:
>>>> I'd be quite willing to send Tim the batteries so that he could do the
>>>> necessary diagnostics.
>>>>
>>>> Do I have a taker?
>>>>
>>>> jh
>>>>
>>>>
>>>>
>>>> ----- Original Message -----
>>>> From: "Tim Hughes" <timhughes@xxxxxxxx>
>>>> To: <olympus@xxxxxxxxxx>
>>>> Sent: Saturday, April 26, 2008 7:10 PM
>>>> Subject: [OM] Re: rechargable lithium ion batteries
>>>>
>>>>
>>>>> Chuck,
>>>>> Actually most common Li ion batteries are not "rated" to give
>>>>> particularly high current,
>>>>> many are only rated 2C. There are some types rated for higher currents
>>>>> typically using a
>>>>> different electrode material, but they are not so common except for
>>>>> special uses radio control
>>>>> helicopter users and power drills. Most common Li-ion cells have built
>>>>> in
>>>>> internal curent
>>>>> limiting electronics, so you cannot draw too high a current, to prevent
>>>>> them self igniting! The
>>>>> NiMH are actually frequently rated for higher current and more
>>>>> importantly, don't have any built
>>>>> in protection electronics.
>>>>>
>>>>> In this particular case, of the so called "3V " lithium batteries
>>>>> these
>>>>> are frequently not
>>>>> Li-ion, but some other Li chemistry like Li-FePO4 (~3.3) with
>>>>> electronics
>>>>> or a diode to reduce the
>>>>> voltage a bit more. They reqiuire a special lower voltage charger too.
>>>>> I
>>>>> would not be surprised
>>>>> if their rated current was quite modest, like <2A.
>>>>> But this is a guess based on not seeing the batteries so, I can't say
>>>>> definitively, except the
>>>>> symptoms fit well with them having limited current capability.
>>>>>
>>>>> Tim Hughes
>>>>>
>>>>>
>>>>> --- Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx> wrote:
>>>>>
>>>>>> But remember that these are supposedly rechargeable lithium ion
>>>>>> batteries and not elemental lithium. The thing that makes lithium ion
>>>>>> batteries potentially dangerous is that they are capable of delivering
>>>>>> far higher currents than alkaline or even NiMH batteries.
>>>>>>
>>>>>> So, I don't think your analysis can be correct if these are truly
>>>>>> lithium ion batteries. But maybe the problem is that they're not
>>>>>> lithium ion.
>>>>>>
>>>>>> Chuck Norcutt
>>>>>>
>>>>>>
>>>>>> Tim Hughes wrote:
>>>>>>> John,
>>>>>>> I am Making some big assumptions here, since I don't have enough
>>>>>>> info from what you have
>>>>>>> said, but I think this is what happens:
>>>>>>>
>>>>>>> When the flash capacitor is completely discharged at a cold start then
>>>>>>> initially the current
>>>>>> draw
>>>>>>> is greatest. As the capacitor charges up a little the current is
>>>>>>> somewhat reduced and then
>>>>>>> eventually drops off rapidly near full charge.
>>>>>>>
>>>>>>> It may be the particular Li batteries you have, can't supply the very
>>>>>>> high initial current of
>>>>>> a
>>>>>>> completely discharged flash capacitor and the internal electronics
>>>>>>> then
>>>>>>> stops the charging,
>>>>>> when
>>>>>>> the battery voltage drops too much at cold start. Once the capacitor
>>>>>>> is slightly charged
>>>>>> using
>>>>>>> the regular batteries, then the Li batteries can supply the lower
>>>>>>> current to continue charging
>>>>>> it
>>>>>>> up. The flash capacitor does not completely discharge even after a
>>>>>>> full
>>>>>>> dump, so once you have
>>>>>>> charged up the capacitor a little, with the regular batteries then it
>>>>>>> will operate fine
>>>>>>> thereafter, off the Li, until you switch it off and leave it to
>>>>>>> discharge completely.
>>>>>>>
>>>>>>> Tim Hughes
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --- om4t@xxxxxxxxxxx wrote:
>>>>>>>
>>>>>>>> I normally use two rechargable 3 volt lithium ion battery packs in an
>>>>>>>> OM flash gun with my
>>>>>> E510.
>>>>>>>> The flash is a dedicated gun for the E series.
>>>>>>>>
>>>>>>>> When the flash has not been used for several days the battery packs
>>>>>>>> do
>>>>>>>> not bring the flash
>>>>>> gun
>>>>>>>> to life. If I change over to four Ultra Duracell 1.5 volt batteries
>>>>>>>> the gun springs to life.
>>>>>> If
>>>>>>>> I then change yet again to the LI battery packs the flash springs to
>>>>>>>> life immediately. It is
>>>>>>>> almost as if the flash needs to be initially energized with the
>>>>>>>> Duracell batteries before the
>>>>>> LI
>>>>>>>> packs become operative.
>>>>>>>>
>>>>>>>> The LI packs are only a matter of a few weeks old, are fully charged
>>>>>>>> and the connector points
>>>>>> on
>>>>>>>> both packs and in the camera are clean.
>>>>>>>>
>>>>>>>> When I start off from "cold" with the LI packs installed in the flash
>>>>>>>> gun, the gun still
>>>>>> remains
>>>>>>>> inoperative even if I jiggle the packs slightly or apply a little
>>>>>>>> pressure to the slide mount
>>>>>>>> cover on the flash gun casing so as to effect a "better" contact
>>>>>>>> between the terminals on the
>>>>>>>> packs and in the camera.
>>>>>>>>
>>>>>>>> Does anyone have any idea about what might be ailing my flash gun and
>>>>>>>> / or LI battery packs?
>>>>>>>>
>>>>>>>> John Hudson
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> ==============================================
>>>>>>>> List usage info: http://www.zuikoholic.com
>>>>>>>> List nannies: olympusadmin@xxxxxxxxxx
>>>>>>>> ==============================================
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> ==============================================
>>>>>>> List usage info: http://www.zuikoholic.com
>>>>>>> List nannies: olympusadmin@xxxxxxxxxx
>>>>>>> ==============================================
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>> ==============================================
>>>>>> List usage info: http://www.zuikoholic.com
>>>>>> List nannies: olympusadmin@xxxxxxxxxx
>>>>>> ==============================================
>>>>>>
>>>>>
>>>>>
>>>>> ==============================================
>>>>> List usage info: http://www.zuikoholic.com
>>>>> List nannies: olympusadmin@xxxxxxxxxx
>>>>> ==============================================
>>>>>
>>>>
>>>> ==============================================
>>>> List usage info: http://www.zuikoholic.com
>>>> List nannies: olympusadmin@xxxxxxxxxx
>>>> ==============================================
>>>>
>>>>
>>>>
>>> ==============================================
>>> List usage info: http://www.zuikoholic.com
>>> List nannies: olympusadmin@xxxxxxxxxx
>>> ==============================================
>>>
>>
>> ==============================================
>> List usage info: http://www.zuikoholic.com
>> List nannies: olympusadmin@xxxxxxxxxx
>> ==============================================
>>
>
>
>
>
> ==============================================
> List usage info: http://www.zuikoholic.com
> List nannies: olympusadmin@xxxxxxxxxx
> ==============================================
>
>
>
==============================================
List usage info: http://www.zuikoholic.com
List nannies: olympusadmin@xxxxxxxxxx
==============================================
|