capacity of Cs vs AAs

This may be a very dumb ?! I use a trail-cam to take pictures of deer. It works off a motion sensor and uses a flash at night. It takes 4 C cells which are good for about 160 pictures but they are about $4.50 for a package of 4. I can also fit 4 AA's in this camera. I know they are both 1.5 watts but was wondering, because of the size difference, how much more capacity a C cell has. AA's would be a heck of a lot cheaper! I have not tried to see how many pictures AA's can take yet but I did put them in to see if they work. I've tried some cheapo C's with horrible results.

Thanks, FishX

Duracell Alkaline AA's are rated at 2850mah; the same in a C cell is rated at 7000mah. That puts the AA at 40% the rated capacity of the C cells. Extrapolating out to the trail cam specs you provided, AA cells would be good for about 64 pictures.

IIRC, C cell alkies are around 8000 mah, and AA alkies around 2500 mah. There are rechargeable C cells, ~5000mah, which is what I would use.


:buddies:

This is a digital camera and not a film camera? Digital cameras are notoriously horrid on alkaline batteries and have a relatively short usage cycle that isn't necessarily reflective of their capacity. The flatter output from NiMH batteries enable longer life with digital devices like cameras and MP3 players. AA batteries are about the same height as a C battery so, as you've found already. If the AA batteries fit (or you can get some AA to C adapters,) give it a try and see how if you get better life than with the C sized alkalines (I suspect it will be minimally about the same or greater with the AA sized NiMH batteries.) If you really want to extend the usage cycle, you could even consider the C sized NiMH batteries; it could could make a significant difference in battery life, but they do add more weight than alkaline C batteries.

I too would use ni-mh c cells or high capacity (2700+)mha AA's. These cells will save you a lot of money over the long run and will perform much better in taxing situations like shooting off multiple pics a second

Considering it's attached to a tree, weight is probably not an issue . Rechargeable Cs are the way to go.

Heck, I'd solder in wires and run them down to a 6v deep cycle battery on the ground.


:buddies: Sorry, wife's at her parent's tonight; I'm bored.

I have a 1.3 megapixel trail camera that requires 4 D cells.I use the Energizer 2500 mah rechargeables,which I believe are sleeved AA's.I can get 80-100 pictures before they are dead.I see guys at my deer lease just constantly replacing dead alkalines with new ones in their cameras.The cost over time has to be outrageous if you do this once a week.That is why I go with rechargeables in this kind of device.Only drawback for me is charging the batteries as we have no electricity at the cabin.

Thanks for the great replies so far! I new you guys would know! I think I'm gonna try the C rechargeables first and see what kind of life I get out of them. I forgot to mention that I use this camera in Michigan were it can easily drop into the the single digits. I also leave it out for weeks at a time so the rechargable 6 volt is a great idea. You also got me thinking that one of those rechargeable 6 volt lantern batteries might work pretty good. The camera holds the C's in two rows of two so what would be the best way to hardwire a single 6 volt?

Thanks again, FishX

I second that, DB. SLA is the way to go for big, cheap storage. I've been shopping for SLAs and a charger (no, I don't know why, but I NEED them ), and the best battery prices I've found are at zbattery.com.

lednut, you could get a big ol' 12V 28Ah SLA and a charger, and then find either:

-a charger with a car cord that can charge AAs, along with some battery size adapters, or
-a charger with a car cord that can charge Ds, along with some real D NiMHs.

Or, just get a whole bunch of real D NiMHs and charge them all up before you go.

fishx65, zbattery has 6V SLAs as well. The one I linked to would probably be good for about a thousand pictures.

EDIT: Forgot to mention that this thread should be moved to the FL Electronics and Batteries forum.

Many chargers will operate from the 12V outlet of an automobile. And there are 15 minute chargers from both Energizer and Duracell that will recharge NiMH batteries fairly quickly (takes a little more time when its running from a car outlet, like maybe 20 minutes.) But the tradeoff is that the high speed chargers are a bit rough on the batteries, where you might only get 150 cycles from a set of batteries rather than the approximately 500 cycles as NiMH batteries are advertised to get.

lednut said:

Only drawback for me is charging the batteries as we have no electricity at the cabin.

Click to expand...

A big drawback of SLA is it can be damaged by freezing when low on charge. So a solar panel charger could be added to make the setup maintenance free.

But if a solar panel were used it could probably charge Ni-Cd C cells right in the camera. NiCd is less affected by cold than NiMH, can better handle a continuous charge from the solar panel, and the device is known to handle 6v from alkaline cells so could probably tolerate some extra voltage from a NiCd charger.

And Brighteyez, that was 150 cycles to 88% capacity for fast charge vs. 91% with slow charge in Tom's tests, showing fast charging is not too rough on NiMH. There is no ultrafast 12v charger for C cells in any case, and SLA do not like to be charged quickly either.

I have four charged before I head out.My chargers that run off of 12v cig lighter plugs are AA/AAA. I know,one day I need to buy some real NiMH D cells.

Do you know how much current your camera draws?

You can get 8 4.5 to 5Ah NiMH C cells for ~$30 shipped on eBay, which offers the same capacity as alkaline at 300mA draw at room temperature. You'll only get 8+Ah from alkaline at 25mA draw.

The strength of NiMH/NiCd over alkaline contrasts even more at lower temperature.

Actually I wasn't thinking SLA, I was thinking big Trojan, Rolls, or Surrete maintainable deep cycle batteries. Maybe golf-cart batteries. 4 x C at 8ah is good for 160 pictures, an 80 or 120ah lead acid would be good for a couple thousand photos, and unlikely to be discharged to a level damageable by single digit temperatures between visits. Recharging at your cabin without power would be a problem, but a 6v charger and a power inverter would work while you drive. Or use two 6v batteries; in parallel for the camera and series for charging from your alternator, through a battery isolator.

Just kicking out ideas, it's midnight and I haven't gotten nearly enough sleep this week.

:buddies:

What do you take the pics for? To make it easier to hunt deer? That wouldn't be fair. On the other hand, it's good to know who is passing nearby at night.

I'm a bowhunter. Those cameras take pictures of big bucks that I never new existed on my property. Most of the big boys only come out at night! It gives me hope when I'm sitting out there in the freezing cold with my bow. They will also show me what big bucks are still around after the gun season. Don't understand the question about how it's not fair. The camera does not kill them, it just takes their picture.


FishX

fishx65 said:

It works off a motion sensor and uses a flash at night

Click to expand...

the motion sensor is constantly using power
the flash is charged and ready at night, this is constantly using power

fishx65 said:

I forgot to mention that I use this camera in Michigan were it can easily drop into the the single digits. I also leave it out for weeks at a time

Click to expand...

....................weeks ay a time too !!!

i reckon your doin well to get 160 pics AA batteries would be a lot worse,
a 6v sealed lead acid battery is the way to go .... cheap as chips off e-bay

...... http://search.stores.ebay.com/6v-sealed-lead-acid_W0QQfromZR8QQsbrexpZWD1SQQsifZ1QQsofpZ4QQssPageNameZWD1SQQsubmitsearchZSearch
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