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02-23-2022, 12:11 AM - 5 Likes   #1
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1.5 volt constant discharge high voltage rechargeable lithium batteries

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A couple of weeks ago, when I got my K-x it was really unusable with any kind of rechargeable nickel metal hydride batteries except the the top of the line Eeneloops. An update on camera made a night and day improvement as to battery life from all batteries, and so far I’ve gotten a thousand shots from the best Energizer lithiums.

I’ve been fooling with rechargeable batteries for fifty years. The NiMh rechargeable ones are good, but only output 1.2 volts.

I didn’t know, they made constant 1.5 volt discharge, lithium high voltage rechargeable batteries. They did not a few years ago when I was trying to find the best solution for rechargeable AA batteries.

I ordered two sets, different brands, both $25 for four and both with rechargers.

The literature says you must use the specified charger. One was conventional, but the EBL brand uses a USB-C port in each individual battery.

These are “smart” batteries, in that each has when fully charged 3.7 volts, then a tiny voltage regulator reduces the output to a constant 1.5 bolts until they suddenly die.

Both types recharged quickly and the conventional ones are in my K-x right now and working the best.

One set was rated 3,500 milliamperes and the other 3,300, and I see where they go up to a rated 5,000.

If you’re looking to avoid replacing expensive lithium batteries I hope these prove out as well as their reviews online.

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02-23-2022, 01:30 AM   #2
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QuoteOriginally posted by MESuperian Quote
These are “smart” batteries, in that each has when fully charged 3.7 volts, then a tiny voltage regulator reduces the output to a constant 1.5 bolts until they suddenly die.
Clever
I remember using a similar idea to keep 13.2v in-car radio equipment transmitting at full power when the engine wasn't running … hadn't considered it in a camera battery!
02-23-2022, 01:36 AM   #3
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Interesting product!

From what I've read, they only seem to provide around 1600 - 1700mAh... but still, the constant voltage is useful. Though, one potential issue because of that is there's no indication of how much juice is left... So in a camera, for example, the battery indicator will show "full" right up until the point where they suddenly cut out - after which there's no voltage whatsoever (something to bear in mind, as there's no trickle to the camera's backup battery or capacitor from that point onwards).

I'm quite tempted to pick up a four-pack of these, just to try them...
02-23-2022, 02:06 AM   #4
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QuoteOriginally posted by MESuperian Quote
An update on camera made a night and day improvement as to battery life from all batteries, and so far I’ve gotten a thousand shots from the best Energizer lithiums.
. . . .

The literature says you must use the specified charger. One was conventional, but the EBL brand uses a USB-C port in each individual battery.

These are “smart” batteries, in that each has when fully charged 3.7 volts, then a tiny voltage regulator reduces the output to a constant 1.5 bolts until they suddenly die.

Both types recharged quickly and the conventional ones are in my K-x right now and working the best.

One set was rated 3,500 milliamperes and the other 3,300, and I see where they go up to a rated 5,000.
When you say "update" do you mean a firmware update on the camera? Interesting. I haven't owned a K-x before, so that's likely why I don't remember. Well, also, less than perfect memory.

Which brand and source are the "working the best" batteries from? I'm tempted to try a set or two as I still have a couple AA powered cameras. link?

Thank you for posting this info. These batteries are not something I've heard of before either. The individually charged ones are ... trippy!

02-23-2022, 02:43 AM - 1 Like   #5
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Another thought crossed my mind... Batteries normally have slightly different capacities due to manufacturing tolerances, degradation over time, etc. I wonder what happens when one cell - the lowest capacity one - decides it's going to shut down from 1.5v to 0v... does that break the series circuit, or... ?

EDIT: ... and yet another thought... Do these drain quicker than regular batteries when out of circuit?

The more I think about them, the more I'm inclined to buy a set... mostly out of curiosity

Last edited by BigMackCam; 02-23-2022 at 03:00 AM.
02-23-2022, 05:14 AM - 3 Likes   #6
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I have not tested those batteries but the capacity in mWh is misleading, normally we have mAh and not mWh:
So to get the real (known) value: 3300 mWh equal 2200 mAh at 1,5 V!!!

So I just read a few reviews on Amazon and one review particular sounded very logical to me:

1. Not useable in the external flash, the batteries just "beeped":
Test on a loadbank revealed that as soon as the surge reached 1,3A the electronics (inside the battery) switched off
This is partly good because it protects the battery but it makes it unusable for higher surge-power

The mentioned "smartness" does it's part for that: If the real voltage is 3,8V but regulated down to constant 1,5V this is o.k. but there must be loss of power (current) because of the regulator. There always is loss of current by law, in this case about 45% at least.


2. The real capacity is more in the region of 1600mAh NiMH's

3. At lower temperatures they had even lower capacity (and not yet below zero Celsius!)

4. No real "state of charge": They trick your Pentax until they switch off and give always the wrong information of "100% full"


So some thoughts:

- NiMH's have a much lower internal resistance and thus deliver power.
- NiMH's are superior in lower temperatures
- NiMH's can give a true state of charge
- Voltage regulators produce heat! This heat is not noticed because the battery is inside the battery-compartment.
- Li-Ions quickcharged die much quicker and are more prone to exploding.
02-23-2022, 06:14 AM   #7
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QuoteOriginally posted by photogem Quote
I have not tested those batteries but the capacity in mWh is misleading, normally we have mAh and not mWh:
So to get the real (known) value: 3300 mWh equal 2200 mAh at 1,5 V!!!
The reason for using mWh is most likely because it has different voltage on the cells and output voltage. They can use same mWh for both.
Otherwise they probably have to state 900 mAh as the cells are 3.7V, which may be even more confusing.

02-23-2022, 06:24 AM - 1 Like   #8
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There is a lot of smoke and mirrors in the battery market at present. Only only needs to look at so called power stations that purport to do all sorts of wonderful things. Inside are some lithium batteries with a grab bag of buck boost converters to different voltages. Some of the milli amp hour claims are outrageous eg marketed as 12 volt systems but the milli amp hour capacity is based off a 5V usb outlet. As all these voltages are created by buck boost converters they have hard current limits well inside the batteries own ability to supply current so struggle with start up currents on motors in ways straight batteries never would..

Problem I see with using the cells the OP is describing is that when a cell closes down due to its battery becoming depleted, it will be a hard close down without warning to the camera. The camera will then just crash. With conventional batteries, they just progressively weaken, the camera will commence and perform a managed shutdown once it detects voltage is below a certain threshold. Imagine a sudden loss of power when one of these new style cells closes down and your camera just happens to be in the middle of a write to your SD card. Probably not a happy ending with a corrupted SD card on your hands.
02-23-2022, 06:55 AM - 1 Like   #9
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QuoteOriginally posted by yucatanPentax Quote
When you say "update" do you mean a firmware update on the camera? Interesting. I haven't owned a K-x before, so that's likely why I don't remember. Well, also, less than perfect memory.

Which brand and source are the "working the best" batteries from? I'm tempted to try a set or two as I still have a couple AA powered cameras. link?

Thank you for posting this info. These batteries are not something I've heard of before either. The individually charged ones are ... trippy!
My K-x is my first Pentax digital and it cost the measly sum of $100 together with 18-55 L kit lens. I’m in love with it.

I’ve found a program that determine shutter count, and it was under 3,000 when I got it.

I’ve had other digital cameras, bigger point and shoots and bridge cameras, that used four AA batteries and those worked fine. My K-x would not even power up with generic NmHd batteries. It ate Eeneloops quickly, it lasted only a bit longer on alkaline. On the expensive lithium batteries it did work.

A K-x is supposed to have three updates and mine has never been updated. The first update more or less fixed the battery life problem. The last two were other minor improvements including using SDXC cards.

When I use 1.5 volt lithium batteries the camera operates snappily and with instant review, and seem to last forever. Using any 1.2 volt rechargeable batteries means it works, but not as fast and especially not quick photo review.

I’ve not tested how long the new 1.5 rechargeable lithium batteries last, but they seem identical to the disposable lithium batteries in performance so far.

Some more observations:

1. The new batteries are light, like the disposable lithiums. Four black Eeneloop batteries are weighty.

2. If you lose your specific charger (especially true for the USB-C port EBL batteries) you have disposable $7.50 each lithium batteries again.

3. They will give no warning (or very little) before they discharge.

4. Neither charger has any provisions for direct 110 volt AC charging. Not a problem these days when there are phone chargers all over every house and plugged in every car, but evidently the chargers want a constant 5 volts or less to charge. The generic set I bought were almost fully charged, and the EBL took an hour and a half on a phone charger to turn the orange lights to blue, then they shut off automatically.

The battery life of the old style disposable lithium batteries in my K-x was almost 2,000 shots. The set I had in there had been used over a thousand times and still registered full charge.

I’m going to shoot these new batteries until they drain, unless I get tired of waiting for them and recharge them. In reading the online reviews, the new type recharge quickly, and are rated over 1.200 cycles.

If you can call EBL a name brand, it seems it’s the only name brand producing these. My others were generic but the charger and little script reads Kratex. Here’s what’s in my Pentax now.

https://www.ebay.com/itm/Double-AA-1-5V-USB-Rechargeable-Lithium-Ion-Batteri...-127632-2357-0

Here’s a link to the EBL batteries that dangle and show lights while they charge:

https://www.ebay.com/itm/EBL-Lot-USB-Rechargeable-Lithium-AAA-AA-Batteries-1...-127632-2357-0

There has to be a reason. If these are good they’ll quit making the others the same as NmHd drove those old ni cads off the market.

Last edited by MESuperian; 02-23-2022 at 07:05 AM.
02-23-2022, 08:00 AM   #10
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I used Delkin RCR-V3s in my K100D and *ist D. They were a decent solution at the time (15+ years ago) before eneloops and the equivalent ikea ladda became commonplace.

They had good battery life, but as others have mentioned, were not without issues:

1) The battery meter never depletes. On the K100D, you could tell the batteries needed charging only by observing the mirror locking up after pressing the shutter button (and no photo was taken - power off the camera and the mirror returned down and you knew it was time to replace the batteries)

2) Over time, they failed to hold a charge for very long. Much like poor quality nimh batteries, they'd discharge quite rapidly and I'd find myself needing to set the date each time I turned on my camera

Eneloops and the high capacity Laddas made in Japan provide excellent battery life and longevity, and are proven. I don't use my K100D much anymore but I've left those brands of batteries inserted for months, and it powers up with a mid-full charge.

If they had existed in 2006 (which I don't think they did in any meaningful way - I bought my first set in 2008), I could have saved a lot of hassle and money by just buying 8xAAs and calling it a day.
02-23-2022, 11:52 AM   #11
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These batteries would be good for some applications. Since they produce very close to 1.5 volts, they would be a good sub for needs requiring that voltage, but since they have an internal regulator, the output current would need to be limited someway to protect that regulator. That's probably the main reason they won't work for high current needs.

These can be placed in series but as mentioned, when one dies, they all effectively die. There are circuits which prevent the lithium cell from discharging beyond a certain point (which can lead to cell failure and the inability to recharge) and when they switch the output off, it's off and the cell is more or less an open circuit.

As mentioned, the mWh rating needs to be converted to mAh for a good comparison (and not sure if the regulator losses are figured into the MWh rating). It appears the smaller lithium cell packed with its charging and regulating circuit, takes up about the same space as a good NiMh battery of equal capacity (ignoring the 1.5/1.2 voltage rating differences). It would be interesting to see some real life tests on these.

Kind of a neat idea but the need to individually charge each cell outside the device (and they should always be charged together to prevent differences in cell capacities) is a bit inconvenient (but this could apply to any rechargeable battery depending on what it's used in).

Last edited by Bob 256; 02-23-2022 at 12:01 PM.
02-23-2022, 02:06 PM - 3 Likes   #12
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I am not going to write much more about AA-Lithiums because I haven't tried them myself and thus there is no verification but just guess and of course some logic based on electronic understanding. Nevertheless, there always can be surprises and thus we shall find out.

The only AA-fed Pentax I use occasionally is the K200D. So maybe one day I will try such Li-Ion AA's. Nevertheless Eneloops Pro work very well with it and particular in cold temperatures, at times I had left it in the car with freezing temperatures, Eneloops took it well while cheap NiMH's show their weaknesses very quickly. That might be different in countries which don't experience such low temperatures (the lowest was -32 Celsius, I was skiing, fantastic blue sky but yet...when you spat you could almost see icecubes popping off the floor)


For those who use the Pentax K-x and had difficulties with AA rechargeables, this thread might be worth checking:
Battery type AA/NiMH/Eneloop in K-x, K-r, K30 K50, K500 as well as *ist/K100/200/2000 - PentaxForums.com

Last edited by photogem; 02-23-2022 at 02:13 PM.
02-23-2022, 11:56 PM   #13
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QuoteOriginally posted by MESuperian Quote
A K-x is supposed to have three updates and mine has never been updated. The first update more or less fixed the battery life problem. The last two were other minor improvements including using SDXC cards.


If you can call EBL a name brand, it seems it’s the only name brand producing these. My others were generic but the charger and little script reads Kratex. Here’s what’s in my Pentax now.

Double AA 1.5V USB Rechargeable Lithium Ion Batteries 3500mWh with 4Slot Charger | eBay

Here’s a link to the EBL batteries that dangle and show lights while they charge:

EBL Lot USB Rechargeable Lithium AAA AA Batteries 1.5V+Micro USB Cable For Mouse | eBay

There has to be a reason. If these are good they’ll quit making the others the same as NmHd drove those old ni cads off the market.
Thank you for all the additional information! I'm thinking of ordering a set or two to try out in my K200D and maybe K30. Thanks!

Also, a big Thank You to @Photogem for all his detailed info now and in the past!
02-24-2022, 04:00 AM   #14
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To date, the only set of batteries I've found that the K-x truly loves (as does the K-200d), are Energizer Lithiums. Buying them in the 24 multipack size, they end up costing about $5.50 a set. At that price, I'm sticking with using what I know will treat the camera right, and will not pose a risk to the camera from leaking (which EBL's 9-volt lithium rechargables have been known to do).

That said, if these new rechargable AAs do turn out to be the cat's meow, it'll be good to have another option to consider down the road.
02-24-2022, 04:55 AM   #15
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QuoteOriginally posted by bobore Quote
To date, the only set of batteries I've found that the K-x truly loves (as does the K-200d), are Energizer Lithiums. Buying them in the 24 multipack size, they end up costing about $5.50 a set. At that price, I'm sticking with using what I know will treat the camera right, and will not pose a risk to the camera from leaking (which EBL's 9-volt lithium rechargables have been known to do).

That said, if these new rechargable AAs do turn out to be the cat's meow, it'll be good to have another option to consider down the road.
The cold of February isn’t picture tanking weather like April will be.

I’ve erased over ninety per cent of the thousand some shots I’ve made on one set of Energizer Lithiums and the same percentage of the hundred or so I’ve made on the new generic rechargeable lithium batteries.

If I had it all to do again I’d bought eight of the same brand. That way is only have to carry one charger.

One great advantage of the new type, is that the camera handles the same as if there was a dedicated li-ion battery. Review is instant. Autofocus and inputs seem instantaneous. A Li-ion camera battery has a meter, but when they decide to die they die right then. Constant discharge is a great advantage, no denying it.

But if stay home because of the snow and not go through McDonald’s I’ll save enough to buy a set of Energizer Lithium batteries rated at 1,900 shots.

In my lifetime toy box stash in the attic is a battery charger I bought over fifty years ago. It worked but that generation of rechargeable batteries really, really sucked.

Most of this, is playing with new technology.

LITTLE TOY TRAINS
Roger Miller 1967

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