[SOLVED] 12 volt battery supply for RF/ IR receiver

[dcweather]

I don't know if anybody on here will be able to help me as I am definitely a non-expert! I am using an RF/IR extender to fire the shutter on my DSLR. This works well. The RF transmitter works from an all-in-one IR remote which has a specially AA battery insert that works as the RF transmitter. The RF/IR receiver transmitter requires a 12v 300ma supply which is via a mains adaptor. Therein lies my problem. I want to use this set up in the field for nature photography and need to power up the receiver. Would it work from a particular 12v battery, a 12v solar panel or is there a better solution. Thanks for any suggestions,
Dave

 

[zuisti]

In my opinion, the cheapest and fastest solution is using an old (but good) car battery

 

[dcweather]

Possibly a bit heavy to carry round the woods! How about a Lithium Ion battery like this?
e.g:-
**broken link removed**

 

[DXNewcastle]

Agreed! Carrying car batteries aroud is to be avoided!
But there are minaure equivalents: small lead-acid 12v batteries used in burglar alarm systems and the like. You can get them from most electronics shops and electrical wholesalers. They'e cheaper, smaller and lighter.

 

[zuisti]

I also agree, of course, there are a lot of modern and small rechargeable batteries on the market.

But a normal car batterie (> 40 Ah) offers more than 120 hours working time assuming the specified 300 mA consumption, compared with the 6 hours of the 1.8 Ah capacity Li-Ion battery, what you found on eBay (for example).

It's only an idea ...

 

[dcweather]

Thanks for your help guys. Actually six hours would be fine because I wouldn't usually be waiting for any willdlife to show up for longer than that and can re-charge for the next trip. So would a battery like that be ok. Would the receiver unit self regulate the current. I'm only going on what it says on the mains adaptor with 12v 300ma. In fact when I put a meter across the output jack it seemed to be showing 20v and 900 ma.
Dave.

 

[DXNewcastle]

I would guess so, yes. The clue is in your meter reading of 20volts, which presumably is when the PSU is disconnected from its load (its voltage will be lower when loaded).
A nominal 12 volt battery can be almost 14volts when newly charged and 10v when approaching discharge. Give it a try!

You could buy two quite small 12volt batts - one for use and one to keep in reserve in the car for longer field sessions. But do take care to avoid accidental shorting of the terminals. Some 12 volt batts have exposed terminals which can easily short out if the both touch a metal surface!

 

[dcweather]

Thanks all for your prompt replies. I will get a Li ion battery like the one above and give it a try!
Dave