On a sunny day (Sun, 31 May 2020 17:25:47 -0000 (UTC)) it happened Martin
Gregorie  wrote in :

>On Sun, 31 May 2020 16:43:04 +0000, Jan Panteltje wrote:
>
>> I have 2 Canon A470 camera, those also uses 2 AA.
>>
>The K100 uses 4 x AA.

Yea         OK, then you need 2 lifepo4 AA and 2 dummy batteries :-)

The big question for me is: will the slightly higher voltage damage my cameras?
From an electronics design POV I would expect there to be a reasonable margin,
not all AA are exactly <= 1.5V either.
And I have repaired one A470 with ebay spare parts so I am trained :-)


>> I was experimenting last week with an other thing with 2 AAA and
>> replaced one AAA with a dummy battery, and the other with a Lifepo4
>> (about 3.2 V nominal).
>>
>This was a while back, and I'm convinced it had more to do with the very
>poor quality of NiMH batteries which were all that were available at the
>time. I eventually discovered Maplins Hybrids which worked well in it and
>didn't fail on 2nd or 3rd charge.
>
>Four years ago I went to India and decided I needed to take something
>less bulky than the K100 + batteries + charger. The small Pentax was an
>obvious non-starter - no viewfinder and trying the see the backside
>display outside in Indian daylight was an obvious non-starter, so ended
>up buying a Panasonic TZ-70 bridge camera: electronic viewfinder, Leica
>lens, 12 MP. That has excellent resolution and is very good in low light
>- so much so that its now my main camera.

Nice.


>Thanks to the TZ-70 I haven't tried putting Sanyo Eneloop batteries in
>the K100 but must try it. I bet that would solve the problem.

I have been using Eneloops in the Canon now for several years, and that is the
reason I want
to test with lifepo4.

The eneloops have an operating voltage way below 1.5V so you get a low battery
warning rather quick.


 >> I charge lifepo4 on the lab supply, set voltage and current limit, watch
>> the time.
>>
>My preferred charger is a Ripmax Pro-peak Prodigy II (a model-flying
>charger) which both charges and measures capacity for SLA (lead-acid),
>NiCd, NiMH, Li-ion and LiPO chemistries, though its really only good for
>Li-ion and LiPO single cells since it doesn't do charge balancing.
>
>If you need a good automatic charger/capacity measurement charger, the
>ones made for RC flying and electric models are a good place to start as
>they tend to be a bit cheaper than a lot of the stuff sold for charging
>phones/cameras/Li-ion power packs and are generally a lot more versatile
>in terms of what they can do, the battery chemistries they support, and
>multi-cell balancing - the latter ability is vital if you use multi-cell
>lithium batteries.

Yes I have 2 RC chargers for lipo, one for my Hubsan drone (2 cell) and
one for my Axion Laser Arrow plane (3 cells), both have balancing.


>> An ebay seller ?accidently? did send me a lifepo4 charger a few years
>> ago...
>>
>A very good battery chemistry. Somewhat lower capacity for a given
>battery size/weight than Li-ion or LiPo but a lot less prone to
>combustion when misused.

Exactly, is is safer, I have tons of all sorts of batteries in the house
and lifepo4 can be charged un-attended.

>As with all of these Lithium-based chemistries, you should use a charger
>that has a charge/discharge profile for the specific chemistry of the
>cells you're using it with or bad things can happen.

Yes, but single cells I often do manual on the lab supply as I know the
profiles.
Also I try charging at 1/2 C, takes longer, but often a bunch in parallel,
little adaptor holds 4 AA or AAA.

--- SoupGate-Win32 v1.05