Simple inverter switch question

[ditchcrawler]

I had it on for several hours last night and it didnt seem to take too much power.. So yeah perhaps thats when its at full blast..

How did you measure it, Ah counter or voltage?

[spadefoot]

Hmmmmm - looking at the photo it appears that the 'speaker' is 150w (power consumption)

 

That equates to approximately 15 amps being drawn from the batteries ( 4 hours use will reduce a 110Ah battery below 50% SoC - were you aware of how much it used ?)

 

It should not be a problem activating the inverter.

Audio power consumption really doesn't work like that. A 150w amplifier doesn't run flat out all the time. Average power use would be maybe 15w.

[Alan de Enfield]

Audio power consumption really doesn't work like that. A 150w amplifier doesn't run flat out all the time. Average power use would be maybe 15w.

 

One can only work with the information given - the photo showed the back of the equipment and the sticker stated 'power consumption 150w'.

 

I would suggest that (to use your terminology) a "150w amplifier' is the output wattage and potentially bears little relationship to the power consumption.

 

(A bit like assuming that an 800w microwave takes 800w - I think not !!!!)

[WotEver]

Nevertheless an audio amp's consumption varies hugely between quiet and loud (unless it has a Class A amp).

 

It's interesting to watch the power consumption rise when you turn up the bass on a 'proper' system. It takes a lot of power to throw those large cones back and forth.

[Geo]

I was aware it would probably use a fair bit of power, but It's worth it

 

I think your buzz could be that the inverter is a quasi-sine wave inverter. The output from it is not a smooth sinewave more a series of steps and a lot of electronics does not like to be fed a quasi-sine wave it upsets them.

 

I would suggest that you ought to buy a 350 watt pure sine wave inverter, that will be powerful enough for the speaker, needing 150 watts and give it a nice clean mains input.

Edited November 27, 2016 by Geo

[Richard10002]

 

And, then the problem that you have is that the Inverter is using twice the power just to 'operate' than you need to run the speaker.

 

You may find that you are drawing 3 amps just to run a small low wattage speaker.

 

My Sterling Pro Combi S 2500W Pure Sine Wave inverter charger uses 4A in power save off mode, when powering nothing. Power save doesnt work for the 240V stuff I power from time to time, (chargers mainly), so pretty much useless.

 

Thus it cant be left on 24/7, and I turn it on and off as I want to power something - dissappointing really.

[ditchcrawler]

 

My Sterling Pro Combi S 2500W Pure Sine Wave inverter charger uses 4A in power save off mode, when powering nothing. Power save doesnt work for the 240V stuff I power from time to time, (chargers mainly), so pretty much useless.

 

Thus it cant be left on 24/7, and I turn it on and off as I want to power something - dissappointing really.

I am glad I bought a Mastervolt.

[nicknorman]

I am glad I bought a Mastervolt.

Me too! 9w or <0.75A on normal mode, <0.05A in power save mode.

[Alan de Enfield]

 

My Sterling Pro Combi S 2500W Pure Sine Wave inverter charger uses 4A in power save off mode, when powering nothing. Power save doesnt work for the 240V stuff I power from time to time, (chargers mainly), so pretty much useless.

 

Thus it cant be left on 24/7, and I turn it on and off as I want to power something - dissappointing really.

 

I think that information such as this should be highlighted (maybe in a pinned 'wiki'), many that have little knowledge of 12v electrics and are struggling with battery maintenance would claim "I don't use much power, just a fridge, a few lights and my inverter is just on standby ready for when I charge my phone / computer"

 

What many don't realise, and using yours as an example, is that the quiescent current (not doing anything current) can be very large.

4 Amps is 96Ah per day.

 

Comparison :- A modern 12v Waeco fridge will use under 30Ah per day

 

I keep 'banging on about this' but its good that others can cite examples from their own experience, hopefully we will get the message across.

 

Other good topics for discussion :

 

1) Power Factor

2) Power surge on 'start-up'

[Chewbacka]

 

My Sterling Pro Combi S 2500W Pure Sine Wave inverter charger uses 4A in power save off mode, when powering nothing. Power save doesnt work for the 240V stuff I power from time to time, (chargers mainly), so pretty much useless.

 

Thus it cant be left on 24/7, and I turn it on and off as I want to power something - dissappointing really.

I would have to say that an inverter with a quiescent current of 4A is not suitable for a boat unless you specifically bought it for occasional use - such as power tools or microwaving one's breakfast porridge. I would not buy one with a quiescent current greater than 2A and a stand-by/power save current of 0.25A.

 

Even this set-up would have the inverter consuming 27AHrs before any power is consumed by the fridge. This is fine for summer cruising with a decent amount of solar, but could be a problem for those living aboard in the dark wet months.

[Alan de Enfield]

I would have to say that an inverter with a quiescent current of 4A is not suitable for a boat unless you specifically bought it for occasional use - such as power tools or microwaving one's breakfast porridge. I would not buy one with a quiescent current greater than 2A and a stand-by/power save current of 0.25A.

 

Even this set-up would have the inverter consuming 27AHrs before any power is consumed by the fridge. This is fine for summer cruising with a decent amount of solar, but could be a problem for those living aboard in the dark wet months.

 

Agreed - but for those without the knowledge to 'ask the right questions', or for those where it is already installed on a boat they have bought, how would they know ?

 

It is these types of answers that the forum could provide to 'newbies' or electrical 'virgins' before they even knew they needed to know it.

[spadefoot]

 

One can only work with the information given - the photo showed the back of the equipment and the sticker stated 'power consumption 150w'.

 

I would suggest that (to use your terminology) a "150w amplifier' is the output wattage and potentially bears little relationship to the power consumption.

 

(A bit like assuming that an 800w microwave takes 800w - I think not !!!!)

Maybe the sticker on the back should have said 'power consumption variable, depending on how loud you play your music'. Unless as WotEver says, it's a class A, then the power consumption is closely related to the output power, but of course the output power is constantly changing. Therefore the power consumption is constantly changing.

[Chewbacka]

I think most appliances only state the full load power consumption, things like hair dryers, washing machines and even phone chargers will vary their power consumption depending on what they are doing - ie, cool or hot setting, phone flat or fully charged etc.

 

Though with audio the peak music power figure quoted doesn't seem to have any real meaning, just looks good in adverts.

[Jess--]

most domestic equipment does only show the maximum power usage.

 

for example a 40" tv I use (not on boat) shows 180w on it's plate but when measured in normal use its actually using less than half of that, I can only assume that the rating is for having the screen at its absolute brightest and the sound system on it flat out.