Do these work, how close are they to a regular AA battery, alkaline and lithium?

[mzjo]

https://www.nkon.nl/fr/xtar-r6-aa-2000mah-protected-1-5v.html
I have just bought a Pentax camera which was cheap because its battery management is US. It rejects fully charged Ni-Mh rechargeables as dead but will work with alkalines, albeit with a very short battery life (15-20 photos). It seems to call anything with less than 1.4v dead! I am considering using lithium batteries so went looking to check what the voltage of a lithium AA was and (as is his way) Google fed me this. Aside the fact of needing a dedicated charger, do these work, do they turn out a genuine 1.5v (or a few 100ths more) or are they simply going to set the camera on fire after the third shot?
The camera is a DSLR which takes 4 batteries (6v total) but has a funny dedicated mains adapter which, given the original new price, is likely to be unobtainable on the secondhand market because I doubt very much that anyone was stupid enough to buy one new. They can be made DIY but not the easiest of devices, the camera connection is made with a thing that replaces a couple of batteries in the battery compartment. I may well have a go at this, others have gone before!

So has anyone experience of these rechargeable lithium AAs? All advice very welcome!!

[aidan.f]

Rather limited details in battery Specification. The maximum discharge current of 1A maybe a bit low as well. I don't suppose you have missed a battery type setting buried in the camera setting sub menus?

[grams]

There’s a graph about halfway down this page:

https://www.xtar.cc/news/Depth-Review-Of-Rechargeable-XTAR-1.5V-AA-Batteries-Green-237.html

They have a voltage converter in them that produces a steady 1.5 volts for most of their life and then drops to 1.1 volts for the final ~ 10%.

[aidan.f]

Very interesting. The ones under test in your link read as having rather more capacity and over 2 amp peak current than the OP's selection.
The last 10% at 1.1 Volts to initiate low battery warning won't be much use in the camera
Maybe the ones below with a, flat Voltage to 100% discharge would be more suitable?

https://www.amazon.co.uk/Lithium-Rechargeable-Batteries-3500mWh-Capacity/dp/B09DTXGLMJ

[mzjo]

Very interesting. The ones under test in your link read as having rather more capacity and over 2 amp peak current than the OP's selection.
The last 10% at 1.1 Volts to initiate low battery warning won't be much use in the camera
Maybe the ones below with a, flat Voltage to 100% discharge would be more suitable?

https://www.amazon.co.uk/Lithium-Rechargeable-Batteries-3500mWh-Capacity/dp/B09DTXGLMJ

The ones in that link are now declared unavailable, restocking unknown.
However I have found these, which might do the job (look to be very similar) https://www.amazon.co.uk/Kratax-Rechargeable-Batteries-Capacity-Constant-8AA-Without-Charger/   (I would be getting the pack with the charger!) I haven't yet looked to see the price on Amazon France!

Since this camera is destined to spend most of it's life on a copystand with a macro lens batteries running out will not usually be a problem (especially since the pack is two complete sets for the camera). I am fairly certain that there is no sub menu that will not have been already discovered by the seller (who was quite clear that the battery check indicated nearly flat, even with fresh batteries - but since it was a shop, probably only tested with rechargeables). It's all a bit of a gamble on my side, but the sums involved are not impossibly high if it doesn't work out long term. I know it can work short term.

[drossall]

Out of curiosity, what is the camera (says a Pentax enthusiast)?

[chrisbainbridge]

Out of curiosity, what is the camera (says a Pentax enthusiast)?

Mains adaptors are available on eBay for almost all cameras in my experience.

[onerousdeporte]

I have an old olympus and was thinking of using a couple of the lithium LS1450? (the ones the same size as AA batteries) 3.6v batteries and two dummies to make a pack, no looking at batteries discarded from those single use e cigarettes.

[fruitcake]

CR-V3 batteries may work with this camera. The rechargeable ones are lithium ion and are sometimes called RCR-V3. They are inexpensive as are the chargers.

[mzjo]

Out of curiosity, what is the camera (says a Pentax enthusiast)?

It's a Kx and it cost 25€ from Kamerastore. If it turns out to be reasonably reliable (at what it does) it will get its sensor cleaned (properly by a shop, no point in wrecking something useful by my being hamfisted).
I am using it with the lenses from my 40yr old Cosina CT1G, the 35mm doesn't get much use on the film camera. For the moment all the signs are good.

[mzjo]

CR-V3 batteries may work with this camera. The rechargeable ones are lithium ion and are sometimes called RCR-V3. They are inexpensive as are the chargers.

Interesting. That Pentax battery compartment is very like mine, except that the polarity arrangement is not quite the same (+ and - of the middle two cells is not quite the same since the middle two go + and - , not + and +)

ETA: Just checked on prices, I'm not sure they would be cheaper than AAs, they look to be a lot more expensive if I'm factoring in 2 sets of 4 AAs (so 4 CR-V3 or RCR-V3) and if the camera goes west AA batteries are still useful in other devices.

[mzjo]

Out of curiosity, what is the camera (says a Pentax enthusiast)?

Mains adaptors are available on eBay for almost all cameras in my experience.

I haven't found one for this one yet (not helped by it having at least two bits. The actual power supply with its lead coming out is available, they must be common to several kits. The bit that goes in the battery box is, if not unique, at least rare and old and google hasn't found me one yet. AC84 power supply doesn't seem to be out there. AC 128 is not the same visually!
This is not a particularly recent camera and not the sort usually used tethered so not a lot of demand for the adaptor, even 12 years ago!

[hubner]

My Pentax dslr stopped working with my usual cheapo AA Ni-Mh rechargeables but white Enloops got the camera working again.

The cheapo ones even when fully charged only ever showed up as half charged on the battery gauge on the camera.

[fruitcake]

The voltage of AA Ni-MH cells drops under load. That voltage drop can be up to 25%, which can be enough to prevent the camera starting up. This is especially true if charging has been sub-optimal, as it often is with modern high current chargers ('fast charging'). Trickle chargers with a current below 50mA will charge Ni-MH cells to a higher voltage (close to 1.5V) and extend the run time of Ni-MH cells, although charging at this rate can take a couple of days.

Li-ion cells are less prone to voltage drop under load, and so they are a more reliable power source for devices that draw a high current at start-up (devices such as digital cameras).

[Diver300]

The voltage of AA Ni-MH cells drops under load. That voltage drop can be up to 25%, which can be enough to prevent the camera starting up. This is especially true if charging has been sub-optimal, as it often is with modern high current chargers ('fast charging'). Trickle chargers with a current below 50mA will charge Ni-MH cells to a higher voltage (close to 1.5V) and extend the run time of Ni-MH cells, although charging at this rate can take a couple of days.

Li-ion cells are less prone to voltage drop under load, and so they are a more reliable power source for devices that draw a high current at start-up (devices such as digital cameras).

That is all true, but the power packs that are Li-ion cells packaged to be 1.5 V equivalent have a voltage converter between the Li-ion cell and the 1.5 V output, so the behaviour of the package under load will also be highly dependent on the voltage converter characteristics.

[Defblade]

I haven't found one for this one yet (not helped by it having at least two bits. The actual power supply with its lead coming out is available, they must be common to several kits. The bit that goes in the battery box is, if not unique, at least rare and old and google hasn't found me one yet. AC84 power supply doesn't seem to be out there. AC 128 is not the same visually!
This is not a particularly recent camera and not the sort usually used tethered so not a lot of demand for the adaptor, even 12 years ago!

I'd think it's be quite easy to make an adaptor that placed the ends of the power lead wires against the necessary contacts. You could even use dead AAs with a bit of insulating tape over the top and the wire then presented to the contact on top of that... but they might leak, so I'd rustle up some appropriately sized dowel instead.

[lissotriton]

Could also look for a "battery eliminator". Basically just dummy AA, with wires to attach to a power supply.
eg https://www.amazon.co.uk/Battery-Eliminator-AIEVE-Adapter-Christmas-black/dp/B07Z9ZJRWW/

[drossall]

For what it's worth, the Pentax Forums have this thread and this one. My K110D has a similar battery set-up, but I've never tried anything like this, so read at your own risk!

[mzjo]

For what it's worth, the Pentax Forums have this thread and this one. My K110D has a similar battery set-up, but I've never tried anything like this, so read at your own risk!

Yes I had seen those threads (or at least one of them) which Google came up with. I have a suitable universal power supply, all I have to do is make the battery box connectors and make sure the polarity is set right on the power supply (and source a suitable female connector so I don't have to wreck the output cable for other uses). For overall versatility rechargeable lithium cells may be better, we'll find out in the long run. I don't do astro-photography or time-lapse which seem to be the most common uses for tethering a camera like this.

Could also look for a "battery eliminator". Basically just dummy AA, with wires to attach to a power supply.
eg https://www.amazon.co.uk/Battery-Eliminator-AIEVE-Adapter-Christmas-black/dp/B07Z9ZJRWW/

I was interested in that but can't quite see what it is doing, not helped by the Amazon spiel quoting 6v ac input and 1.5v dc output. It's less than half the price of lithium rechargeables but I'm uncertain that it will actually work.

Got a pack of 4 regular lithium AAs in the shopping today. 10€ in Carrefour so a bit pricey for a long term fix but we'll see how they last before (probably) trying rechargeables.