Battery advice.

[batema (Mark)]

Hi,
I have just bought a Kendrick dew heater and wonder what size battery would suit to run this helpfull device for the whole night.
Mark

[erick (Eric)]

As in a heater strap or the heater controller?

If the controller, what heater straps do you plan to use with it?

What is "the whole night" in maximum number of hours for you?

From that information we can estimate amps drawn and then total power needed which leads to battery choice.

[batema (Mark)]

I have two straps running or soon to be running. One is a four inch and the other an eight inch that will run for 8 hours if I have a good night.

[erick (Eric)]

A controller?

However, check out this information and look up each of your heater straps and get the wattage figures and come back to us.

https://www.bintelshop.com.au/HTML/K...fications.html

[erick (Eric)]

In the meantime, you may wish to start reading up about batteries:-

http://www.windsun.com/Batteries/Battery_FAQ.htm

[GrampianStars (Rob)]

http://www.ktbattery.com/crown-batte...ry-27dc24.html
this 7DC 105Amp will do the job really well

[batema (Mark)]

Thank you all. That will get me going.

Mark

[erick (Eric)]

Last question Mark, how much do you want to spend? There are cheap options and there are expensive options.

[batema (Mark)]

I really need my head read at the moment. I have a thousand Oaks controller and the straps not a Kendrick (idiot) and I had heard that I can buy second hand batteries from a electric wheelchair place and the charge $1 per amp hour so I thought I would go down that track. The controller I bought is this one http://www.myastroshop.com.au/produc...sp?id=MAS-078A
I don't know the biggest size battery but the guy said a 90amp hour would be $90 and it is only 1 yr old.
Mark

[jenchris (Jennifer)]

You could heat a caravan with that.......for a week

[erick (Eric)]

Good controller!

Without worrying any more about drain, why don't you look for a 30-40 Ah battery. That should do what you want - one 4" strap and one 8" strap, not running at 100% all the time.

OK, I'd better try to estimate. A 4" DewNot strap draws under 0.2A and an 8" draws under 0.4 A - lets say 0.6A. Let's add a bit for the controller to dissipate - 0.2A should be plenty - total 0.8A. OK, between friends, let's make that 1A to be generous. For 8 hours that is about 8Ahr. Let's double that so you don't discharge the batter too far - say 16Ahr. So even a 20Ahr battery should be plenty. (But will you add more straps in future??)

If you have a second hand option in batteries, that is worth pursuing - $30-40 is worth a try.

But I'd be looking looking for backup batteries for electrical equipment. They come on the market all the time and have probably spent their entire life on trickle charge and never were discharged. I'd worry that wheelchair batteries may have been discharged too low a few times.

Any used battery, you want to see tested - not just voltage, but voltage under load. I picked up one for someone the other day and the second-hand supplier put a big Arlec meter on it to show me firstly voltage unloaded and then that it held a respectable voltage under a reasonable load.

[batema (Mark)]

Thanks all. I'm off to buy a battery but I might get a million amp hour so the heat will evaporate the constant rain we are having. Not looking good for the Christmas holidays again.

Mark

[RobF (Rob)]