Power for amp at outdoor gig

[2strings2frets]

Has anyone used a power inverter with a car battery to power a bass or guitar amp? If so how long will the battery last, ac power is not available. Load in and out is not an issue so full stack with deep cycle battery is ok. Generator is possible but not preferred. Anyone with practical experience? Thanks

 

[Drummerboy2]

Is your amp a Class D? Look into a "Pure Sinewave" inverter. Try to find one that fits the wattage you will be consuming with your am/rig. They usually come with battery cable adapters. These are not cheap ranging any where from $120 on up, depending on wattage.

 

[2strings2frets]

Is your amp a Class D? Look into a "Pure Sinewave" inverter. Try to find one that fits the wattage you will be consuming with your am/rig. They usually come with battery cable adapters. These are not cheap ranging any where from $120 on up, depending on wattage.

Is your amp a Class D? Look into a "Pure Sinewave" inverter. Try to find one that fits the wattage you will be consuming with your am/rig. They usually come with battery cable adapters. These are not cheap ranging any where from $120 on up, depending on wattage.

Yes it is class D,300 watts. I was just checking HF and a 400 watt inverter is less than $50.00. It says modified sine wave however what’s the difference and more importantly will it work?

 

[Redbrangus]

There is a correlation between your amp's output power in watts and the power consumed (measured in watts) to produce those watts, but it isn't as simple and direct as what you're thinking. You'll need at least a 600--1000-watt inverter, I would think. At any rate, don't confuse your amp's output power with it's power consumption.

What amp are you thinking of using?

 

[Drummerboy2]

Yes it is class D,300 watts. I was just checking HF and a 400 watt inverter is less than $50.00. It says modified sine wave however what’s the difference and more importantly will it work?

As the gentleman said you need at least 600-1000 watt inverter to be safe. 800 watt Pure Sine wave inverter should be good. If there is not one in that wattage, go for the 1000 watt.

 

[jthisdell]

I did a couple gigs where one of the band mates had an inverter on his battery, kept the car idling and ran our very modest PA and amps off it. Worked well, a car idling is very quiet, not at all like a generator.

 

[Wasnex]

Has anyone used a power inverter with a car battery to power a bass or guitar amp? If so how long will the battery last, ac power is not available. Load in and out is not an issue so full stack with deep cycle battery is ok. Generator is possible but not preferred. Anyone with practical experience? Thanks

If this is a one off and you plan to put on a concert, the easiest and cheapest route is to rent an inverter generator for the entire band.

One bit of advice, these generators usually have an Eco mode where the generator idles down to save fuel and then speeds up as power is required. Music is dynamic and a generator in Eco mode can't respond fast enough, so it will starve the equipment of power. So, when the band is playing, the generator should be run at full power instead of Eco mode.

If you are really committed to battery power, then a related thread from yesterday is here: Battery/Inverter for Pair of QSC K8.2s

If you plan to use a small class D amp like a Trace Elliot Elf or TC Electronic BAM 200, you could probably get by with a fairly small pure sine power station from a company like Jackery or Goal Zero. I have considered the Jackery 240 myself. The size of powerbank you needs depend on how much average power you need and how long you need it.

Portable Power Products - Jackery
Compare Portable Power Stations/Goal Zero

 

[agedhorse]

A pure sine wave inverter is a very different type of inverter than a modified sine wave inverter. A PSW inverter is the better choice by far, next would be a quiet inverter type generator.

A MSW inverter would be my last choice.

 

[dbase]

A 1200 watt inverter used to power my servers (3) in work for about 20-30 minutes.

 

[2strings2frets]

A 1200 watt inverter used to power my servers (3) in work for about 20-30 minutes.

Great, thank you. It looks like an inverter generator is required then as my gen set is too noisy. I will have to read some equipment labels at rental companies. On line specs for Honda and H F don’t specify pure or modified sine wave power. We have a months time so it is a work in progress. Thank you all for your advice. I appreciate it very much.

 

[Redbrangus]

The Honda EU-series of inverter generators are the way to go -- they are "quietized" in addition to having good stable sine-wave output. They've been updated, so the numbers aren't exactly what they used to be, but basically they offer 1000, 2000 and 3000 watt models in manageable sizes. I wouldn't get anything smaller than the 2K one, but you're in a better position to calculate what your total load would be -- add up the potential power consumption needs of everything that's going to be plugged into the genny, and then allow yourself some margin. And Was is right, forget about the Eco mode on the engine.

 

[dbase]

Great, thank you. It looks like an inverter generator is required then as my gen set is too noisy. I will have to read some equipment labels at rental companies. On line specs for Honda and H F don’t specify pure or modified sine wave power. We have a months time so it is a work in progress. Thank you all for your advice. I appreciate it very much.

Honda is the best and its quiet.. 1000/2000 watts for around $800-$900 bucks.

 

[Redbrangus]

Honda is the best and its quiet.. 1000/2000 watts for around $800-$900 bucks.

Honda has a couple of different series -- the EUs are the quiet ones and the ones with sine-wave output. But they're more expensive than that to buy -- like $2K for the 2200 watt one. [correction below] Luckily, the OP isn't looking to buy, and they're as common as carrots at rental yards. They'll probably know what you mean if you say you want a Honda inverter generator -- they're incredibly popular. Around here, I think it's less than $100/day for the 2Kw, but I haven't had occasion to rent one in a while.

Edit: I took a moment to check on prices for Honda gennies, and I was pleasantly surprised to see that the EU1000i can be had for less than $1K and the EU2200i is only $1200 if you don't want to spring the extra $220 for a camo paint job.(!) Plus, now they're Bluetooth-enabled...what a world!

 

[dbase]

Honda has a couple of different series -- the EUs are the quiet ones and the ones with sine-wave output. But they're more expensive than that to buy -- like $2K for the 2200 watt one. [correction below] Luckily, the OP isn't looking to buy, and they're as common as carrots at rental yards. They'll probably know what you mean if you say you want a Honda inverter generator -- they're incredibly popular. Around here, I think it's less than $100/day for the 2Kw, but I haven't had occasion to rent one in a while.

Edit: I took a moment to check on prices for Honda gennies, and I was pleasantly surprised to see that the EU1000i can be had for less than $1K and the EU2200i is only $1200 if you don't want to spring the extra $220 for a camo paint job.(!) Plus, now they're Bluetooth-enabled...what a world!

And they make coffee in the morning

 

[Redbrangus]

Man, this is lot easier to do these days than it was when I was scuffling around street fairs, etc. Homer's (you might know it as Home Depot ) has the Honda inverter generators in their rental stock at local stores: under $60/day for the 2Kw and $82/day for the 3Kw, although they do warn that the price will be determined at the local store. I would presume that the price would vary somewhat regionally as well. But still -- I wish I had that sort of easy access back in the day.

 

[Slevage]

I did a couple gigs where one of the band mates had an inverter on his battery, kept the car idling and ran our very modest PA and amps off it. Worked well, a car idling is very quiet, not at all like a generator.

Just be sure the car’s alternator can keep up with the power demand.
Using too big of an inverter will kill the car’s charging system if components are not sized correctly.

 

[Redbrangus]

If you go the route of using a car, be sure to also run the air conditioner so you can use the car as the 'green room'.

 

[1958Bassman]

If you want to use batteries, find a bunch of 6V golf cart batteries, wire pairs of them in series and parallel the pairs. Also, remember that the voltage will drop over time and that means your electronics will become extremely unhappy, at some point. Batteries have a capacity and depending on the type (flooded lead/acid, AGM, Lithium Ion, etc), that means the voltage drop and current will decrease at some rate that may allow them to do what you want, or they'll puke sooner than you can tolerate.

Batteries are the power source that's the most pure, but they have limits. Best choice- find a quiet generator that produces pure sine wave.

If you know someone with a larger boat that has large Group 29 or Group 32 batteries, you could use those- their reserve is greater than cranking batteries and you could use a generator with 12VDC output to partially recharge if you will be taking a break.

Look at the manual for the amp, to find the power usage- a 400W inverter won't be enough for the amp because somehow, 300W is still 300W and with 12VDC supply, that comes to 25A- that inverter will be clamped to the battery or using a cigarette lighter for its connection and the lighter will never be able to deliver 25A.

 

[tchristian]

1000 watts at 120vac is only 8 amps. Plenty for a bass amp, likely not enough for 3 amps and a PA.

 

[1958Bassman]

1000 watts at 120vac is only 8 amps. Plenty for a bass amp, likely not enough for 3 amps and a PA.

But the actual power source is one or more batteries, which are at 12VDC, so the power calculation needs to be done for that voltage. The line voltage used by the amplification is secondary and will only be applicable if the inverter is able to supply 120VAC under load.