Compact plus T1® on battery power

Portable PA
1

Hi L1® Support.

I’m posting this on behalf of L1® owner JB95.

“Tom-at-Bose answered the question comprehensively for powering an L1 Compact with an inverter. What power inverter would be required to run a T1 ToneMatch as well as the L1 Compact?”

Here’s the background information.

quote:
Originally posted by Tom-at-Bose:
Informational Post: AC Power in for L1 Compact

This is especially for those who want to run the L1 Compact with an inverter connected to a car battery or from a Power Pack.
Note: The L1 Compact accepts all AC Power In voltages from 100V to 240V, the different part numbers change the power cord in the box.

Here are the AC Power in levels we have measured on the L1 Compact, please realize that these are approximate and vary greatly with audio content.
               Power   230V    120V    100V

Idle:           12 W   0.06A   0.1A    0.12A
(no audio out)

Filling a room: 30 W   0.14A   0.25A   0.3A

Full Out:       60 W    0.3A   0.5A    0.6A
(Red LED blinking)

Note: The AC line power in can peak around 100W during a loud burst.

We have also tested the L1 Compact with several DC to AC Inverters, mostly the low cost “Modified Sine Wave” (actually three level square wave) ones and all have worked very well, there is no buzz problem from the ones we tried.
I recommend that an inverter of at least 300W be used ($30 to $35 US), less then that has not been tested.

Here are measurements we took, realize this also includes the inverter efficiency:
 
                            Current from 
               Power      12V Battery to Inverter

 

Idle:           12 W         1.5  Amps
(no audio out)

Filling a room: 30 W          3 Amps

Full Out:       60 W          6  Amps
(Red LED blinking)


There are also “Power Packs” available which have the battery built in with the inverter.
To find out how long one of the “Portable Power Packs” will run divide the amp hour rating of the battery by the amps from the list above (usually divide by 3), this is assuming it uses a 12V battery.

Hopefully you folks find this information useful,
Tom


Original Post


and here’s a picture of the details on my T1 ToneMatch® Audio Engine Power Supply


Thank you!

ST

2

Hello,

What an interesting inquiry! First I’ll note the official maximum wattage spec for L1 Compact is 200 watts max. Keep in mind, maximum power draw would only occur with the L1 playing at maximum, blaring volume. Normal power draw at “normal” volumes will be something much less than 200 watts.

The T1 power supply rating of 81-100 VA is the same as 81-100 watts (volts times amps is watts). So I consider T1 maximum power draw 100 watts.

So based on these official specs this setup presents a maximum draw of 300 watts. A good rule of thumb for an inverter would be to oversize by at least a factor of two so at least 600 watts for the inverter.

Keep in mind official specs can be conservative (as Tom’s lower wattage numbers show). Feel free to measure your power draw at home using regular utility and/or inverter power. If you have access to a kill-a-watt or similar, it will tell you how much power in watts your Compact and T1 are drawing with your sources at your levels. Sometimes real world testing is best.

Thanks and good luck!
MattS-at-Bose

3

Thank you Matt!

That’s great information and insight.

ST

4

If the power supply is rated at 18 volts at 1 amp, would that not equal max 18 watts.

 

amps x volts = watts , yes?

 

Don't understand where that " T1 uses up to 100 watts" comes from.

 

Very confusing specs Bose....

 

I doubt the T1 actually needs the full 1 amp. Most manufacturers over build the supply.

Anybody care to share the actual amp draw?

 

I have a Cioks 7 brick that will put out 18 volts @ 500 mA. Be great if it could be used instead of carrying two bricks.