heating from a split charging system

[sallyandsean]

I have a 65ah battery and a 300w invertor, I have just got a 240v,120w greenhouse heater to take the cold edge off but the heater will only power for a few seconds and turns on and off and continus on like that. Am I expecting too much from my lesuire system to power it or am I doing somthing wrong :?: Please help!

 

[Matt_B]

Are you sure the heater is only 120W? It seems quite low? If it is only 120W then the numbers suggest that it should work fine, as at 240V it will only be drawing 0.5amp (roughly not allowing for any losses). At the 12V side it will be drawing 10amps - again should be fine.

 

[Trikky2]

120 watt heater :lol: :lol:

 

[aogrady]

Hi!

As mentioned above, 1/2 amp on 240, but 10A draw on 12V, but your inverter will be taken the 12V and upping to 240, i'm not too sure on the current draw in this scenario, but i guess it's much less than 10A. One thing, your inverter may be 300W, but that's maximum, maybe peak to peak load, so in real terms could be 150W continuous? You may be overloading the inverter?

Here is a online calculator which is easier than trying to do the math for current and power in your head. It's all simple ohms law - you just have to remember the formula
http://www.the12volt.com/ohm/page2.asp" onclick="window.open(this.href);return false;

Another thing, is 120W gonna keep you warm? It's only 2 normal light bulbs after all? Maybe you would be better with a gas heater or use a hob, you can get both with disposable canisters, and then maybe use the inverter for other things like running the radio, charging the mobile phone, and running the laptop?

Though saying that, it may well just take the chill off overnight of you have little ones?

Cheers!

Alistair

 

[sallyandsean]

Hi!

As mentioned above, 1/2 amp on 240, but 10A draw on 12V, but your inverter will be taken the 12V and upping to 240, i'm not too sure on the current draw in this scenario, but i guess it's much less than 10A. One thing, your inverter may be 300W, but that's maximum, maybe peak to peak load, so in real terms could be 150W continuous? You may be overloading the inverter?

Here is a online calculator which is easier than trying to do the math for current and power in your head. It's all simple ohms law - you just have to remember the formula
http://www.the12volt.com/ohm/page2.asp" onclick="window.open(this.href);return false;

Another thing, is 120W gonna keep you warm? It's only 2 normal light bulbs after all? Maybe you would be better with a gas heater or use a hob, you can get both with disposable canisters, and then maybe use the inverter for other things like running the radio, charging the mobile phone, and running the laptop?

Though saying that, it may well just take the chill off overnight of you have little ones?

Cheers!

Alistair

Thanks mate for that, the idea was just to take the edge off for the kids without the risk of fire.