Author Topic: Mains to car battery - electronic techy question...... any takers? (Read 5638 times)

suziequeue · « **on:** November 13, 2011, 08:17:54 am »

I asked this question on the poultry thread but I have since done some research so it's now become a slightly more technical question......

I'm trying to get a mains operated poultry drinker warming pad to run off a car battery.

The poultry warmer that I have identified includes a 24V adapter and has a usage of 12W.

I have discovered that to do this I need a power inverter but don't know which one to get. There seems to be a bewildering array of prices and wattages to choose from.

The inverters that I have identified are all 12V and the power runs from 250 - 5000W which is reflected in the price!

I am assuming that I can get a 250W inverter as my heating pad only needs 12W. Is that correct?

What about the 24V adapter? Does that mean it adapts to 12V?

Any advice would be welcome. Electronics was never my strong point in physics.

robert waddell · « **Reply #1 on:** November 13, 2011, 08:57:52 am »

if it can run on 24v it does seam odd normally it is 12 volts
if it is 24v that is not a problem just 2 batteries connected to make the 24v IE connect positive to negative on the two batteries that leaves a positive and and a negative to connect to the appliance you have 24volts
12 volts will not work anythink that requires 24 volts
in short forget the inverter and get 2 decent batteries that is if the unit DOES work on 24 volts

suziequeue · « **Reply #2 on:** November 13, 2011, 10:17:51 am »

Thanks Robert

We've come up with a slightly different solution which is to get a couple of 12V motorcycle hand grip pads which will connect directly to a car battery and has an on/off switch.

Other advantage is that the pads only cost £3.99 rather than £29.99 for the poultry pad.

I shall give these a go and report back to this forum with my results as I remember there was quite alot of chat on the poultry forum last year about how to keep drinkers from freezing.

Susanna

robert waddell · « **Reply #3 on:** November 13, 2011, 10:42:05 am »

are you going to run them continuous or just for short periods as the gloves would be intended

suziequeue · « **Reply #4 on:** November 13, 2011, 11:34:41 am »

Mainly just for short periods during the day on the really cold days but it would be interesting to see how they hold up with continuous use

hughesy · « **Reply #5 on:** November 13, 2011, 11:45:41 am »

I reckon they'll flatten the battery fairly quickly and will have a minimal effect on the water once it gets properly cold.

suziequeue · « **Reply #6 on:** November 13, 2011, 02:45:18 pm »

Well - researching these imponderables is all part of the fun.

bazzais · « **Reply #7 on:** November 13, 2011, 05:12:34 pm »

Sounds interesting - but will probably lead to you buying new car batteries every 2 months.

Car batteries are not designed to be run down to low levels - which any warmer will run it down too unless topped up everyday.

A marine battery will fair better, but cant help thinking that taking water into the hutch in the morning and evening may be the only way.

I'm still interested on how long the charge last for though - be great if it does work.

Baz

suziequeue · « **Reply #8 on:** November 13, 2011, 05:27:06 pm »

Quote

A marine battery will fair better, but cant help thinking that taking water into the hutch in the morning and evening may be the only way.

Gosh - if only it was just morning and evening!!

I had sort of assumed that the heat pads would be similar to the chicken fence running off the car battery which seems to last about 30 days.

My electronics isn't that hot though

Womble · « **Reply #9 on:** November 13, 2011, 05:56:55 pm »

Baz is right. If you're going to buy batteries specially, get 'deep cycle' marine / campervan type ones. These are designed to be charged and discharged, and will therefore last much longer. They'll also be better for using with your electric fence in the summer.

My solution last year was a 240V submersible aquarium heater, like the one below, stuck into a bucket of water:

This was very cheap, and worked very well (a bit too well actually, and I had to run it on a timer for 15 minutes out of every hour, or the water got warm). Is 240V definitely out of the question for you Suzie? Alternatively, I wonder if you can get 12V versions?

ambriel · « **Reply #10 on:** November 13, 2011, 07:05:14 pm »

That's a useful tip, Womble. I've got an old fishtank heater somewhere. I'll have to thinkabout looking it out for our girls.

mab · « **Reply #11 on:** November 13, 2011, 11:31:48 pm »

If Dan will forgive me a link to another forum, you might consider building a solar heated trough:-

http://fieldlines.com/board/index.php/topic,136476.0.html

not technically very challenging and whilst it might not eliminate the problem of freezing entirely, they seem to significantly reduce the (electrical) heating required, and if you're a long way from the mains it might save you a lot of effort in lugging batteries.

this chap is in Canada and has to deal with average winter temperatures even colder than Scotland (if you can believe that's possible).

there are a couple of further references if you read down.

mab

suziequeue · « **Reply #12 on:** November 14, 2011, 06:35:26 am »

WOW11

Lots of food for thought. Thankyou

Plantoid · « **Reply #13 on:** November 20, 2011, 12:15:25 am »

A simple way perhaps ,

use two , three or five watt 12 volt bulb with soldered on wires in parrallel or in landrover type or trailer bulb holders and run to a battery that is ....say 30 feet away might be an easier option . if you can get a battery charger on mains to continually recharge the battery insituation so much the better .

Glue or screw the bulb holder /wires to the base of the drinker so thesix or ten watts of heat can warm the bottom of the drinker , protect from draughts.

In theory if one bulb blows you should still have a working one if you check it every day .
You can also use the same idea to make a heated seed propagation tray .