Hello guys!

I would like to ask you for advice. I am trying to create a setup for busking, that would be powered with a battery. However, I am not very good with electricity, and I am having difficulty figuring our what the total power draw my system would have, and what would be the best type of battery for it (I am guessing a 12volt gel battery?). I would really appreciate if someone could help me calculate this properly...my main problem is that on each part of my equipment, the power intake is written in a different form... Here is my list of equipment:

2x Boss GT-10B - 800mA 9v AC
1x TCHelicon Touch 2 - 1A/12DC <14W
1x MXR EQ (10Band) - 26mA

2x Loudspeaker - 110 Watt each (input power rating).

I am not even sure if this information is enough to calculate this? Really, any help or advice would be appreciated!

Thank You!

 

How long do you need it to run for?
I assume the loudspeakers have built-in amplifiers (since you haven't included an amplifier in the list) if so, what supply voltage do they require?

 

If the Boss units need an AC input then an inverter will be required.

 

Hello guys!

I would like to ask you for advice. I am trying to create a setup for busking, that would be powered with a battery. However, I am not very good with electricity, and I am having difficulty figuring our what the total power draw my system would have, and what would be the best type of battery for it (I am guessing a 12volt gel battery?). I would really appreciate if someone could help me calculate this properly...my main problem is that on each part of my equipment, the power intake is written in a different form... Here is my list of equipment:

2x Boss GT-10B - 800mA 9v AC
1x TCHelicon Touch 2 - 1A/12DC <14W
1x MXR EQ (10Band) - 26mA

2x Loudspeaker - 110 Watt each (input power rating).

I am not even sure if this information is enough to calculate this? Really, any help or advice would be appreciated!

Thank You!

AFAICR: Everyday Practical Electronics recently published a project for a class-D busking amplifier.

Class-D is highly efficient and makes the most of whatever battery you've got. But they went one further than that by using a lithium pack with high energy density and much lighter than an SLA battery of similar capacity.

 

The boss units are powered from 9VDC so they won't need an inverter but the speakers might.

 

When creating a power budget for devices like the ones listed, you need real measured current draw values, not just power supply maximums as are often printed on the AC to DC converters or their associated connection points on the equipment. Power usage will also vary significantly with use. High volume settings, heavy bass and strongly compressed backing tracks will all consume more power than their counterparts, for example.

Once you have some "real" numbers, you'll be surprised that you don't need a truckload of batteries, just a small crate full. If you mount everything on a lightweight 2-wheel cart, it could end up being easily portable.

 

A rough guess is 3.6 amps if the speakers are run at 11 watts each (allowing for a ten to one, peak to average sound level, with no distortion on the peaks). I seriously doubt you are going to run 110 watts in each speaker because the sound would be horrible. The real specification needed is about the amplifier.

 

How long do you need it to run for?
I assume the loudspeakers have built-in amplifiers (since you haven't included an amplifier in the list) if so, what supply voltage do they require?

Hi! Thanks for the reply I would expect it to be able to run for about 3 to 4 hours. The speakers are active speakers, so they have built in amplifiers. This is what the website says about their voltage for the UK/Europe (where I am based) - 230 V~, 50 Hz (T 3.15 A H 250 V). I have made a calculation based on the information I had, and I estimated the whole system's power consumption to be maximum 250 Watts... Does that sound plausible? Or did I get it way off?

 

A rough guess is 3.6 amps if the speakers are run at 11 watts each (allowing for a ten to one, peak to average sound level, with no distortion on the peaks). I seriously doubt you are going to run 110 watts in each speaker because the sound would be horrible. The real specification needed is about the amplifier.

Hi! Thanks for the reply! The speakers are active so they have built in amps in them. And yes, the 110 is the maximum power consumption, so it would definitely not be constant!

 

When creating a power budget for devices like the ones listed, you need real measured current draw values, not just power supply maximums as are often printed on the AC to DC converters or their associated connection points on the equipment. Power usage will also vary significantly with use. High volume settings, heavy bass and strongly compressed backing tracks will all consume more power than their counterparts, for example.

Once you have some "real" numbers, you'll be surprised that you don't need a truckload of batteries, just a small crate full. If you mount everything on a lightweight 2-wheel cart, it could end up being easily portable.

Hey thanks for the reply! I know the numbers on the manuals are their maximum power ratings, but not really sure how to find out the "real" numbers. The 2 wheel cart is kinda what I am aiming at... I have so far estimated the power consumption to be at maximum 250watts...does that sound plausible based on the information I had?

Cheers!

 

AFAICR: Everyday Practical Electronics recently published a project for a class-D busking amplifier.

Class-D is highly efficient and makes the most of whatever battery you've got. But they went one further than that by using a lithium pack with high energy density and much lighter than an SLA battery of similar capacity.

Hi! Thanks for the reply! Yes, class D seems to be doing wonders for what I need! I will have a look into those lithium packs for sure
Cheers!!

 

If the Boss units need an AC input then an inverter will be required.

yes yes indeed...plus I'm in the UK, so the speakers will be running AC as well I believe..

 

The maximum current would be around 20A @ 12V but music has a high average to peak power ratio so the system may only have an average draw of around 5 amps or 60W. You will require an inverter which will introduce some inefficiency, and the quiescent current consumption of the amplifiers will be a significant factor. If you went the lead-acid route you could probably start with a battery capacity of 50 or 60Ah i.e. something the size of a typical car battery for 3-4 hours use but a larger deep-cycle marine battery would be a much better long-term option.

There's no definitive answer because there are so many variables that affect the power consumption and the battery capacity but it's always better to have plenty of reserve capacity.

 

The maximum current would be around 20A @ 12V but music has a high average to peak power ratio so the system may only have an average draw of around 5 amps or 60W. You will require an inverter which will introduce some inefficiency, and the quiescent current consumption of the amplifiers will be a significant factor. If you went the lead-acid route you could probably start with a battery capacity of 50 or 60Ah i.e. something the size of a typical car battery for 3-4 hours use but a larger deep-cycle marine battery would be a much better long-term option.

There's no definitive answer because there are so many variables that affect the power consumption and the battery capacity but it's always better to have plenty of reserve capacity.

Thank you very much!! That sounds around what I thought I would need Would you please advise me on the inverter I would need to get? From what I read, a pure sine inverter would be best, as I will be operating with more delicate electronic equipment? Once again, thank you for your advice!

 

I think that a 300W true sine wave inverter would be ok. Avoid the cheapest as, apart from other things, it could introduce noise into the system. Take a look at Meanwell inverters, they have quite a good reputation and are not expensive.

 

I think that a 300W true sine wave inverter would be ok. Avoid the cheapest as, apart from other things, it could introduce noise into the system. Take a look at Meanwell inverters, they have quite a good reputation and are not expensive.

Thank you very much! Very much appreciated

 

I think that a 300W true sine wave inverter would be ok. Avoid the cheapest as, apart from other things, it could introduce noise into the system. Take a look at Meanwell inverters, they have quite a good reputation and are not expensive.

Last question! If I connect an inverter of a higher rating (700W) will it affect the whole system? Or does it simply mean that the inverter can handle loads up to 700?

 

You can use an inverter of any size as long as it meets the minimum power requirement of the system.

 

You can use an inverter of any size as long as it meets the minimum power requirement of the system.

Perfect Thanks!!

 

Hi! Thanks for the reply! Yes, class D seems to be doing wonders for what I need! I will have a look into those lithium packs for sure
Cheers!!

Lithium has very high energy density - and there have been accidents where all that energy got released at once!

Unless you *REALLY* know what you're doing, its best to use a commercially built charging system rather than attempt to design your own.

Lithium cells tend to go violently exothermic if you over charge them even by only a little bit!