[ElvisQ]

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I have an idea, but I don't know how explain it. So I do this image:



Is it posibble? dangerous?
The Quantum batterys are small and it can be clipped to belt
Meaby the Quantum batterys have not an AC plugin, I don't know. Meaby we need another battery... but this is the idea.

[jatrax]

If the battery has an AC plugin, which means it has an internal converter then no reason it would not work. But I don't think that battery has a converter. It would be theoretically possible to wire up something that would allow that battery to power the camera but a careful analysis of voltage and polarity would be required. Not something I would recommend doing.

[snostorm]

Hi ElvisQ,

I think not, unless there's some significant voltage regulator in the battery adapter. The Quantum (nice Q connection in the name at least ) batteries are meant for flashes that use 4-5 AA batteries, so 6-7.5 volts. The Q battery is 3.5V.

A possibly more practical solution would possibly be a battery grip that attached to the body and used 2 AAA or AA batteries, which would give you @ 3V. I don't know if this might be enough to power the Q effectively, but I think it might. I'm not a fan of the battery grips for DSLRs, but I'd actually like something that might extend the right side of the body out a little further for use with adapted lenses. With an adapter mounted, especially the Pentax OEM, there's very little to grab on the right side of the body. . . and of course, more battery capacity would always be welcomed with the Q.

Scott

[johnmflores]

I did something similar with a Panasonic GH2, I rigged up a battery used for RC cars and it worked great. IIRC, there was an issue with having enough voltage, and not just what was listed on the stock battery, but enough to not trigger the camera's low battery sensor. Find out the voltage that the Q's AC adapter outputs and find a battery that matches.

[keithlester]

Is it just me, or does this miss the point of having the Q? Small, compact, pocket friendly, surely it would make more sense to just carry a couple of extra charged batteries, small, compact, pocket friendly. Even a dozen spare batteries would weigh less than the Quantum unit and probably last longer.

[Rob22315]

DC-DC converters are commonplace and efficient so this is a doable do - if you want to carry around a car battery in your backpack.

What's the voltage on the Quantum battery? Check Mouser to see what DC-DC converters are available with the correct conversion. The rest is a simple matter of wiring it all up correctly. You might even be able to skip the pricey Pentax converter box and cable and simply get the correct size plug from Mouser as well..

[theeggplanthunter]

I'm toying with the idea of using a 18650 battery with built in BMS attached to a grip screwed into the tripod mount. the 18650 is a lion with 3.7 nominal (same as the oem) and the BMS should let you connect it directly to the NP-50/D-li68 adapter; it should net about 2x the life of the oem. Done right, you could slap an IR remote in the grip too, and fire the shutter while holding the grip.

Some more ingenuity, and you could add in a viewfinder, one of those old screw-in units that went with certain cine D-mount lenses and have a nifty package.

The biggest issue is finding the AC adapter. Pentax never really produced theirs afaik (which is overpriced anyway) but if you look on amazon for the "CP-50" for fuji cameras, I managed to snag one for the cost of an oem battery.

[Rob22315]

I agree, there are very large rechargeable batts available at the correct voltage so there's no need for converters and adapters.

[johnmflores]

I agree, there are very large rechargeable batts available at the correct voltage so there's no need for converters and adapters.

For the GH2 the question was, "what is the correct voltage?" The GH2 battery is rated at 7.2V. The GH2 AC adapter is rated at 8.4V. IIRC, an external 7.2V battery connected to the GH2 via the AC coupler would not work.

Does anyone have the AC adapter for the Q? What's the output voltage?

[crewl1]

For the GH2 the question was, "what is the correct voltage?" The GH2 battery is rated at 7.2V. The GH2 AC adapter is rated at 8.4V. IIRC, an external 7.2V battery connected to the GH2 via the AC coupler would not work.

Does anyone have the AC adapter for the Q? What's the output voltage?

I have the Kapahen version. The output voltage is listed at 5v, 2a.
I checked it with a Radio Shack meter and it does show 5.22 volts at the battery terminals.
A charged Li-68 gives 4.1 volts on the meter.

[crewl1]

<I wouldn't do it but> Maybe you could use this? 3 7V 10000 mAh Li Po Battery for GPS Mobiles Backup Power Supply 156870 | eBay
Looks like it could give 10x the run time.
You can get a universal charger from Radio Control airplanes for the charging duties.
YMMV, not responsible for melted cameras or fried body parts

[Rob22315]

<I wouldn't do it but> Maybe you could use this? 3 7V 10000 mAh Li Po Battery for GPS Mobiles Backup Power Supply 156870 | eBay
Looks like it could give 10x the run time.
You can get a universal charger from Radio Control airplanes for the charging duties.
YMMV, not responsible for melted cameras or fried body parts

There are larger ones out there, I saw one at 35 amp hours. As long as the voltage is correct, nothing will melt.

[theeggplanthunter]

The trick is to get a battery type that won't explode and has a BMS built in. The camera won't see the SOC(state of charge) so if it's lithium ion, you could kill it by over draining it unless a BMS (battery management system) shuts power flow off below a certain voltage. It's the same problem for charging, but instead of killing the battery, you make a chemical fire.

That said, the camera should have an internal DC-DC regulator, so anything from 4.2-3.0V should work since that is the working range of voltage for the OEM cell.

-edit-
After some looking, the optio VS20 ac kit looks to output 4.3 V. I'm worried that the 5v output of aftermarket generic adapters will be too high. The battery chemistry is the same, so the working voltage should be similar. I have a spare Q, and I have a 5v AC adapter in the mail, so I might risk it for kicks.