Camera's Odd Battery Preference

What is your camera's name?

I call it Fred, but it prefers the more formal "HP Photosmart M425." Another friend, who I call Sylvie, also has a fussy camera.

If you have a particular affinity for Fred, you could rig an external battery pack and plug it into his Jack.

_{Sorry, I'm not much help.}

Good plan. Makes it rather less easy to tote, but may be worth it. I had planned to build an external supply based on a 6V sealed lead-acid battery (maybe something like this), built into a box with a switch-mode regulator & fitted with a shoulder strap.

Events overtook.

Saw this geek once, who had taped a bundle of batteries to the back of his camera with black electrical tape. It was ugly, but he didn't seem to care.

Fred= F*rking ridiculous electronic device

Seems appropriate in this context.

I have a couple of temperamental digital cameras, an old Kodak which will be fine to use all day with a set of NiMH AA batteries and then decide to be current hungry with the other set (identical name brand)I use for it, the other camera will drain the batteries if left in it over a period of days.

must be a camera thing..

Curiouser and Curiouser. Let's label 3 sets of batteries A, B, and C. Only set A would run the camera yesterday. Set B was charged enough that the charger wouldn't light up for them. So I drained them enough to charge again, while I re-charged set A as well, with set C maintaining the camera memory. After charging, same story. Set B or C would not boot the camera, but A would. So, I mixed sets A and B, and either combination worked. I tried C again, and it works now too. Maybe it is an intermittent fault. I'll still make that load tester, when I figure out an appropriate resistor.

Little would surprise me with HP cameras. I have an M417 (which I've long since stopped using). The photo quality was very good, but the power supply circuitry was the worst I've ever come across. I also found great variability in how long it would run on a pair of fully charged cells (sometimes a couple of hundred shots, sometimes only about 50).

I didn't keep track of which cells were "good 'uns", as I had a pool of rechargeables used for various applications. I'd generally just cycle them round according to what needed them next.

I once climbed a hill (about 20mins of puffing and panting) to get a particular shot, to find that the rechargeables died before I could frame the shot. "No worries" I thought, getting out a pair of new alkalines, which I figured should be good for half-a-dozen shots. It went straight to the "red screen of death" .

I tested the cells later and found they were well within spec - just that the crap HP circuit couldn't cope.

Bleh.

Not a lot of help, I know - just some sympathy.

You should definitely test the voltages on load.

Be interesting to hear your results if you do the comparative tests.

GA

Make a way to get a voltage reading in the camera so it is the load. Aluminum foil makes a good contact in confined space. -- JHF

I have an HP 735, and have had good luck with lithium batteries. Poor luck before that with rechargeables.

I have quite a collection of rechargeables, older Ni-Cd and a lot of Ni-MH. I never knew what condition these things were in. I finally found the answer to the problem; a battery conditioner/charger that actually tells you the batteries capacity, and will refresh ones that are suffering from "memory" effect. The link is to Amazon, because that's where my search for the model took me, it may be available at a better price other places.

LaCrosse BC-9009 Battery Conditioner

Now I write the AH capacity on the batteries, and can match them up this way. It also did a good job of resurrecting the cells that had very limited capacity. The "refresh" cycle does a number of charge/discharge cycles until it doesn't see any improvement in capacity. The charge and discharge currents can be set independently for the 4 "slots" of the charger. It really does have a lot of bang for the buck as far as features go, I haven't used my "dumb" chargers since I got this thing. You are limited to AA and AAA, but that covers most "toys" these days.

I don't have stock in the company, just a satisfied customer :)

One additional note about your experience with the batteries, if you are checking them "open circuit", it's not going to tell you much about the state of charge. You really need to test them under load.

Tom D.

I think the Tenergy Model T-6988 Computer Controlled Ni-Cd and MiNH Smart Charger for 1-10 pcs. AA and AAA is a viable alternative to consider. I got mine on eBay, for a little less than the Amazon price for the LaCrosse.

The Tenergy has some advantages and disadvantages:

• I didn't look in detail at the LaCrosse, but in the Tenergy, each cell (up to 10) is charged individually--you don't need to charge in pairs.
• The charge state on each cell is monitored individually. But the only indication of full charge is an LED (that tells you charging in progress, discharging in progress (for reconditioning), or fully charged).
• It is a slow charger (which suits me fine)--iirc, it will do something like a 1200 maHr. AA cell in 8 hours--see next bullet
  
• It can handle batteries only up to a certain maHr. capacity due to a timer that is built-in to prevent gross overcharging. Over that maHr. capacity, you have to unplug the charger (to reset the timer), then replug it, and let it take up to another 8 hours to charge. (The "normal" circuitry in the charger will prevent an overcharge, it will switch to a trickle charge. If you're around and see the green, you can take the cell out early.) So, at the end of 8 hours, if the LED to indicate charged is not green, unplug and replug to reset the timer. The failure to charge could also be due to a bad cell, so if after two (or perhaps 3 for really big maHr capacity cells), you may suspect a bad cell.

Because I haven't looked in detail at the LaCrosse, I can't tell you how it compares.

The LaCrosse is fully independent on all 4 slots, for all the functions, charge, discharge, test and recondition. The charge current it settable, it defaults to 200mA, which is slow, but gives the best life for the batteries. If you are in a hurry, it can be set up to a full amp (1000mA). It has a metal strap the batteries rest on, that monitors temp. They really did cover all the bases with these chargers. Modern microcontrollers make it possible for them to do it for under $50.

Tom D.

Thanks! One feature the Tenergy doesn't have (iirc) is temperature cutoff. Too bad I didn't notice the LaCrosse back when I was looking for a charger.

I have a HP camera also(don't remember model #) that eats alkalines and eats rechargables even faster. I agree your problems are likely due to internal cell resistance. I tried numerous rechargables and have found the only fix is to use lithiums. Seem to last forever.

I've read a lot of the replies (well, all of them, actually). I like your idea of measuring the battery voltage under load.

I'd like to see it measured while it is under load from the camera. I wonder--is there an external power jack to provide power to the camera from an AC adapter?

If so, you might be able to measure the voltage under load using that--one way or another find an adapter (with pigtails) that fits that jack, then connect your voltmeter to the pigtails and watch the battery voltage as you turn on the camera, and maybe as you do a few other things.

(The reason I say might is that there might be a diode in the camera in the circuit from the jack designed to prevent damage if somebody connects an adapter with incorrect polarity. I would not expect that, but it might be there.)

You could be right about the diode (or some different route into the PSU circuit). My M417 has "3.3V" marked beside the power jack.

Re: You could be right about the diode (or some different route into the PSU circuit).

You won't find out without either trying it or dissecting the camera ;-)

"... dissecting the camera" - not a bad idea! I could rip out the power supply circuit and fit a decent one! May yet make a good camera out of it.

Incidentally, I lent it to my daughter to take on a school trip to China. Dam' batteries gave up half-way up the hill to the Great Wall, so she had to fall back on her 'phone to record the trip of a lifetime. _{(She did have spare cells, a charger and a wall outlet adapter - but she was 13yo, and was/is somewhat on the dizzy side).}

;-)

If you can rig a bridge across the camera batteries to an ammeter with a min max & average detection you will find that some cells do not supply enough start up current and have a larger voltage drop.

The larger capacity cells have a lower internal resistance and should work better, NiMH is my preference nickle cad tend to leak.

I had this problem with a Kodak camera but is now OK after sorting out the cells. It even did this with some so called heavy duty 1.5 volt cells, so there is a lot of variability in quality.

Just checked - M417 seems to draw about 1.5A during power-up (just using a 'dumb' hand-held DMM). Used the only cells I've got to hand with any charge in them - "red screen of death" before I could measure any more.

However, the 1.5A is a useful result. If the cells used can't supply that at sufficient voltage, it'll never boot up.

Update - here's the power supply section of the spec in the manual:

Typical power usage: 2.1 Watts with Image
Display on. 4.5 Watts maximum power usage.
Power sources include:
• Either two non-rechargeable AA Alkaline or
Lithium batteries, or two rechargeable AA
NiMH batteries. Rechargeable batteries can
be recharged either in the camera using the
optional HP AC power adapter or optional
HP Photosmart M-series dock, or separately
in the optional HP Photosmart Quick
Recharger. Average recharging times of
NiMH batteries via each of these methods
are provided in the section Recharging NiMH
Batteries on page 151.
• Optional HP AC power adapter (3.3 Vdc,
2500 mA, 8.25 W)
• Optional HP Photosmart M-series dock
Recharging in camera with the optional HP AC
power adapter or optional HP Photosmart
M-series dock: 100% in 15 hours.

Re: Typical power usage: 2.1 Watts with Image Display on. 4.5 Watts maximum power usage.

Yeah. 4.5 watts is about 1400 mA at 3.3 volts. Pretty good slug of power, which lower maHr probably have trouble meeting, especially if they are not quite up to par.

Having cells at an equal age and capacity is important, but not possible for most people.

I have a good charger and about every 4 years or so, I buy a set of the newest latest highest capacity re-chargeables.....

Do not forget that some chemistry of batteries are limited to the number of recharges before they fail......its often only as few as 2000. Laptop batteries are a prime example.....

I find this blog very interesting and informative, thanks to all concerned.

" ....its often only as few as 2000" - care to check the number of zeros there, Andy? That's about 5½ years at one cycle per day .

If its only one cycle per day.

Personally my laptop gets switched on (and off) up to a dozen times a day, sometimes more......before I knew about the limited charges, I was getting a new batter in the guarantee time!!!

My laptop works hard!

Those who only switch on once would be better off with PC!!

Guess it depends how you define a 'cycle'. Don't suppose any manufacturers quote for "discharge to 75% - recharge" etc.

BTW, do you recharge after each time you use it? (From your post, "...batteries are limited to the number of recharges before they fail..." it suggests you do). Or do you wait til it's nearly dead, then run for a recharge?

If say ON/OFF on battery ten times then recharge, surely each recharge should be considered as one "cycle"? So that would be once per day (ish)? Back to 5½ years (ish)?

Sadly, the Laptop battery designers and the charger designers just look at the battery and see its terminal voltage, if it isn't completely full (and looking at it dropped the voltage a bit), so they charge........

It does not matter if the battery is 9% full or 99% full, a charge is initiated.

Before I knew that re-charges were finite, I used to switch on with the mains lead not inserted, till the laptop said it was almost empty and then charge. Its a crap way to do it but at least it increased battery life dramatically......

I learnt here on CR 4 some time ago that its the number of recharges that makes the REAL difference!!