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cbueche
2008-08-29, 04:48
Hi,

as the power supply is external, I was thinking about adding a 12V battery pack under the box, with a loader, but that would add 2 Kg to the box, so probably not a good idea. Suggestions ? 2-3 hours autonomy in the garden would be cool !

Charles

Mnyb
2008-08-29, 05:46
I wished there were batteries in it from the beginning for similar reasons.
Nimh cells dont need to be that heavy.

iPhone
2008-08-29, 08:50
Hi,

as the power supply is external, I was thinking about adding a 12V battery pack under the box, with a loader, but that would add 2 Kg to the box, so probably not a good idea. Suggestions ? 2-3 hours autonomy in the garden would be cool !

Charles

A 18VDC Dewalt cordless rechargeable battery will give you a good 3 hours. Maybe even 4 hours depending on WiFi signal level and volume level.

dean
2008-08-29, 09:45
On Aug 29, 2008, at 8:50 AM, iPhone wrote:
> A 18VDC Dewalt cordless rechargeable battery will give you a good 3
> hours. Maybe even 4 hours depending on WiFi signal level and volume
> level.

Using something besides the included power supply is definitely not
supported at this time, will void your warrantee, may cause a fire and
bring a pox upon your house.

That said, Boom operates more efficiently at 12v, using an 18v battery
will just give off more heat.

lanierb
2008-08-29, 11:52
Since its power usage seems to be on the order of 8 watts or less, this should be easy. A stack of 8 good NIMH AA's should give you about 2 hrs. If you want to go all the way to D's (expensive) you're up to about 11+ hrs. Hook up a pack of them with the right connector and you're in business.

Since it's so simple, shouldn't Slim Devices consider offering the pack themselves as an accessory?

Michaelwagner
2008-08-29, 21:15
Since its power usage seems to be on the order of 8 watts or less
Idle power usage.

The power specs say 1A minimum @ 12V, so the supply must be able to provide at least 12Watts for when the box is on and playing music.

ccrome2
2008-08-29, 23:52
On 8/30/08, Michaelwagner <
Michaelwagner.3exufb1220070003 (AT) no-mx (DOT) forums.slimdevices.com> wrote:
>
>
> lanierb;333918 Wrote:
> > Since its power usage seems to be on the order of 8 watts or less
> Idle power usage.
>
> The power specs say 1A minimum @ 12V, so the supply must be able to
> provide at least 12Watts for when the box is on and playing music.


Hmmm, where does it say that? Because it's wrong. The system is designed
for a 2.5A (30 watt) supply. Below 75% volume or so, power
consumption doesn't change much playing or not playing -- it's about 6
watts.

When you're cranked up to 100%, the average consumption goes up by a couple
of watts.

This is because of 2 different factors:
1) volume that we hear is roughly logarithmic with power. (i.e. dB = 10
* log10(power)). .1 watts is only 10 dB quieter than 1 watt.
2) music is very 'peaky'. The difference between the average (RMS) power
and peak is about 15. 30 watts is only for the very peaks of the music, so
RMS power increase would be 30/15 = 2 watts over the standby power.

-Caleb

Michaelwagner
2008-08-30, 04:53
You know, Cal, I wondered about that. Hard to get 30 watts out from 12 watts in.

I'll show you mine if you show me yours.

Here's where it says 12 watts. Well, it doesn't say 12 watts, it says 1A@12V
http://www.slimdevices.com/pi_boom.html#power

Power input
12V DC, regulated
Center positive, sleeve ground
Connector: 2.5mm ID, 5.5mm OD, 11mm long
Min supply rating: 1000mA


Now show me yours. Where in that whole document does it say 30 Watt audio?

dean
2008-08-30, 06:43
You are absolutely right, that's confusing. We'll take it off.

On Aug 30, 2008, at 4:53 AM, Michaelwagner wrote:

>
> You know, Cal, I wondered about that. Hard to get 30 watts out from 12
> watts in.
>
> I'll show you mine if you show me yours.
>
> Here's where it says 12 watts. Well, it doesn't say 12 watts, it says
> 1A@12V
> http://www.slimdevices.com/pi_boom.html#power
>> Power input
>> 12V DC, regulated
>> Center positive, sleeve ground
>> Connector: 2.5mm ID, 5.5mm OD, 11mm long
>> Min supply rating: 1000mA

Michaelwagner
2008-08-30, 07:07
I never compared it to mine, because I know the betas shipped with the "wrong" power supply anyways.

SuperQ
2008-09-06, 00:25
Here's a neat option:

http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2069

13Ah F size nimh pack. I guess I will need to do some consumption tests to see what the boom needs, but at 15W you could run for a long time on that.

pippin
2008-09-06, 00:56
you are saying that these old LiIon laptop batteries I've got around here will give me 8 HOURS of playback if I just find out about their connector pinout (4100 mAh @12V, they are rated at 15V but I understand Boom will just convert the extra power to heat). Man, I even got two 6600 mAh units,... Here's my next project :-)

pfarrell
2008-09-06, 01:10
pippin wrote:
> you are saying that these old LiIon laptop batteries I've got around
> here will give me 8 HOURS of playback if I just find out about their
> connector pinout (4100 mAh @12V, they are rated at 15V

I think you have slid a decimal place here. 4100 mAh is 4.1Ah. At 12v,
4.1 amps x 12 is 49.2 watt hours.

The Boom is rated at 30 watts. At ten volts, that's 3 amp hours, so you
might get a bit more than one hour, rounding liberally. This assumes you
can actually get the rated amount out.

You should derate them a lot, batteries don't really deliver the claimed
voltage through their life. The Boom will draw less if its off, but
that's not what you are looking for.

And old batteries don't come close to the new ratings.


--
Pat Farrell
http://www.pfarrell.com/

radish
2008-09-06, 08:47
I added a couple of questions to the Boom FAQ about power usage, and to be accurate I used a meter. I couldn't get it to pull more than about 10W however loud I played it, and at "normal" volumes it was in the 8W range. So maybe batteries will last a little longer than the worst case scenario based on 30W?

aubuti
2008-09-06, 09:11
I added a couple of questions to the Boom FAQ about power usage, and to be accurate I used a meter. I couldn't get it to pull more than about 10W however loud I played it, and at "normal" volumes it was in the 8W range. So maybe batteries will last a little longer than the worst case scenario based on 30W?
I have one of the later beta units (came with a bag) that has an 18v power supply, and my Kill-a-Watt meter says 14 watts whether it's on or off. Is the meter likely to be that far off, or is something else at work? For other devices (SB2, SB3, NAS) it reports wattage close to what others report, but for some reason my Boom readings are much higher. Ideas?

ccrome2
2008-09-06, 09:37
Yeah, the earlier units took a bunch of power, especially at 18V. The 8W
while playing moderately loud is the correct value for production units.

The 30 watt rating is just during the absolute peaks of music.

-Caleb


On Sat, Sep 6, 2008 at 9:11 AM, aubuti <
aubuti.3fbq6z1220717703 (AT) no-mx (DOT) forums.slimdevices.com> wrote:

>
> radish;337417 Wrote:
> > I added a couple of questions to the Boom FAQ about power usage, and to
> > be accurate I used a meter. I couldn't get it to pull more than about
> > 10W however loud I played it, and at "normal" volumes it was in the 8W
> > range. So maybe batteries will last a little longer than the worst case
> > scenario based on 30W?
> I have one of the later beta units (came with a bag) that has an 18v
> power supply, and my Kill-a-Watt meter says 14 watts whether it's on or
> off. Is the meter likely to be that far off, or is something else at
> work? For other devices (SB2, SB3, NAS) it reports wattage close to
> what others report, but for some reason my Boom readings are much
> higher. Ideas?
>
>
> --
> aubuti
> ------------------------------------------------------------------------
> aubuti's Profile: http://forums.slimdevices.com/member.php?userid=2074
> View this thread: http://forums.slimdevices.com/showthread.php?t=51667
>
>

pippin
2008-09-06, 09:37
pippin wrote:
> you are saying that these old LiIon laptop batteries I've got around
> here will give me 8 HOURS of playback if I just find out about their
> connector pinout (4100 mAh @12V, they are rated at 15V

I think you have slid a decimal place here. 4100 mAh is 4.1Ah. At 12v,
4.1 amps x 12 is 49.2 watt hours.

The Boom is rated at 30 watts. At ten volts, that's 3 amp hours, so you
might get a bit more than one hour, rounding liberally. This assumes you
can actually get the rated amount out.

You should derate them a lot, batteries don't really deliver the claimed
voltage through their life. The Boom will draw less if its off, but
that's not what you are looking for.

And old batteries don't come close to the new ratings.


--
Pat Farrell
http://www.pfarrell.com/

Caleb said: 6W @ 12V. I thought he should know.

ccrome2
2008-09-06, 09:45
It will go down to 5 Watts with the display turned off. So, set your idle
and off brightness to 'Dark'. Playing moderately loud is still only 6
watts or so. Only when you crank it, will it go to 10 Watts on average.

On Sat, Sep 6, 2008 at 9:37 AM, pippin <
pippin.3fbrcn1220719203 (AT) no-mx (DOT) forums.slimdevices.com> wrote:

>
> pfarrell;337275 Wrote:
> > pippin wrote:
> > > you are saying that these old LiIon laptop batteries I've got around
> > > here will give me 8 HOURS of playback if I just find out about their
> > > connector pinout (4100 mAh @12V, they are rated at 15V
> >
> > I think you have slid a decimal place here. 4100 mAh is 4.1Ah. At 12v,
> > 4.1 amps x 12 is 49.2 watt hours.
> >
> > The Boom is rated at 30 watts. At ten volts, that's 3 amp hours, so
> > you
> > might get a bit more than one hour, rounding liberally. This assumes
> > you
> > can actually get the rated amount out.
> >
> > You should derate them a lot, batteries don't really deliver the
> > claimed
> > voltage through their life. The Boom will draw less if its off, but
> > that's not what you are looking for.
> >
> > And old batteries don't come close to the new ratings.
> >
> >
> > --
> > Pat Farrell
> > http://www.pfarrell.com/
>
> Caleb said: 6W @ 12V. I thought he should know.
>
>
> --
> pippin
>
> ---
> see iPeng at penguinlovesmusic.com
> ------------------------------------------------------------------------
> pippin's Profile: http://forums.slimdevices.com/member.php?userid=13777
> View this thread: http://forums.slimdevices.com/showthread.php?t=51667
>
>

SuperQ
2008-09-06, 09:51
I did some tests with my production Boom and a Watts Up Pro plug-in meter.

Standby power:
display level - watts
0 - 4.7
1 - 5.5
2 - 5.5
3 - 5.8
4 - 6.0
5 - 6.3

Playing SomaFM Groove Salad (AAC -> FLAC transcoded)
volume level - watts
0 - 6.5
10 - 6.6
20 - 6.5
30 - 6.6
40 - 6.7
50 - 6.7
60 - 6.7
70 - 6.8
80 - 7.0
90+ - 8-12

What I noticed after I passed 80 volume was that it would peak above 10 watts when there was more bass in the track. The update rate on my Watts Up may not be fast enough to correctly measure the usage.

Overall it seems that the average usage is well below the rated output of the 30 watt adapter included.

ccrome2
2008-09-06, 10:00
On Sat, Sep 6, 2008 at 9:51 AM, SuperQ <
SuperQ.3fbs1n1220720102 (AT) no-mx (DOT) forums.slimdevices.com> wrote:

>
> I did some tests with my production Boom and a Watts Up Pro plug-in
> meter.
>
> Standby power:
> display level - watts
> 0 - 4.7
> 1 - 5.5
> 2 - 5.5
> 3 - 5.8
> 4 - 6.0
> 5 - 6.3
>
> Playing SomaFM Groove Salad (AAC -> FLAC transcoded)
> volume level - watts
> 0 - 6.5
> 10 - 6.6
> 20 - 6.5
> 30 - 6.6
> 40 - 6.7
> 50 - 6.7
> 60 - 6.7
> 70 - 6.8
> 80 - 7.0
> 90+ - 8-12
>
> What I noticed after I passed 80 volume was that it would peak above 10
> watts when there was more bass in the track. The update rate on my
> Watts Up may not be fast enough to correctly measure the usage.
>
> Overall it seems that the average usage is well below the rated output
> of the 30 watt adapter included.



Yep, all your numbers look spot-on. The interpretation of the 30 Watts is
the thing thats slightly off. Yes, you'll hit 30 Watts (or higher really)
during the peaks of music. Music is a very 'peaky' signal though, with a
crest factor (peak-to-average) up to 20 or so. Believe me, when you're
playing music at 100%, the peaks of power consumption are over 30 Watts.
Your meter is too fast to get a good average (it jumps around), and too
slow to get an instantaneous peak measurement.

-C

>
>
>
> --
> SuperQ
> ------------------------------------------------------------------------
> SuperQ's Profile: http://forums.slimdevices.com/member.php?userid=2139
> View this thread: http://forums.slimdevices.com/showthread.php?t=51667
>
>

pippin
2008-09-06, 10:05
SuperQ, was the before or behind the power adapter?
With the Laptop battery I will not need a power adapter, it's already 15VDC
And the battery I think about using (the small one at 4100mAh) is not new but almost unused, used to be my backup battery... I'll give it a try once I find the pinout.

MrC
2008-09-06, 10:17
... and my Kill-a-Watt meter says 14 watts whether it's on or off. Is the meter likely to be that far off, or is something else at work?

As an FYI, various reviews have measured the Kill-a-Watt to be off by as much as 10%.

pippin
2008-09-06, 11:40
OK, here's my first try.
Another battery. LiIon, 2400 mAh, 11.1V
That's the small battery of my old notebook. I also own two bigger ones with 4800 mAh.
This one was pretty empty (two of five indicators), 10.5V

Works perfectly. Boom plays. Full volume (didn't compare volume levels, but sounds fine), Battery does not get hot.

Now I will fully charge one of the bigger ones and do a long-play test. Well, maybe I first charge the small one and do the test...

Cool! Really small, a little duct tape and here is my portable boom!

ccrome2
2008-09-06, 12:09
Hi All, Do not use Lithium (Li-Ion or Li-Po) batteries on Boom! They can
EXPLODE. Seriously. Warranty is one thing, but explosions are something
else all together.

With Boom, there is a high inrush current, that can damage Li-Ion packs
too.

Of course, when battery packs are used with the products they are designed
for, all the safety considerations have been taken care of by the
manufacturer. But using a Lithium pack outside of its designed product can
be really bad.

-Caleb




On Sat, Sep 6, 2008 at 10:05 AM, pippin <
pippin.3fbsqn1220721003 (AT) no-mx (DOT) forums.slimdevices.com> wrote:

>
> SuperQ, was the before or behind the power adapter?
> With the Laptop battery I will not need a power adapter, it's already
> 15VDC
> And the battery I think about using (the small one at 4100mAh) is not
> new but almost unused, used to be my backup battery... I'll give it a
> try once I find the pinout.
>
>
> --
> pippin
>
> ---
> see iPeng at penguinlovesmusic.com
> ------------------------------------------------------------------------
> pippin's Profile: http://forums.slimdevices.com/member.php?userid=13777
> View this thread: http://forums.slimdevices.com/showthread.php?t=51667
>
>

mrfantasy
2008-09-06, 12:25
I'd say that most voltmeters aren't going to catch those transient power bursts, so even metering it and seeing say, 14 watts, that's already a time average.

For all the talk about power supply issues in Squeezeboxes and whether the stock power supply has enough reserve for transients, you'd think people would want to be more conservative with ensuring a portable power supply could deliver enough current for something that's actually driving speakers. And Caleb's warning about blowing batteries up is a very real one, that will be exacerbated by high transient currents.

Any thoughts on a 12v car adapter? The car battery should be able to drive it just fine, and it might be fun for tailgating with WiFi nearby (or with devices that provide WiFi to a 3g phone or radio).


Yeah, the earlier units took a bunch of power, especially at 18V. The 8W
while playing moderately loud is the correct value for production units.

The 30 watt rating is just during the absolute peaks of music.

-Caleb


On Sat, Sep 6, 2008 at 9:11 AM, aubuti <
aubuti.3fbq6z1220717703 (AT) no-mx (DOT) forums.slimdevices.com> wrote:

>
> radish;337417 Wrote:
> > I added a couple of questions to the Boom FAQ about power usage, and to
> > be accurate I used a meter. I couldn't get it to pull more than about
> > 10W however loud I played it, and at "normal" volumes it was in the 8W
> > range. So maybe batteries will last a little longer than the worst case
> > scenario based on 30W?
> I have one of the later beta units (came with a bag) that has an 18v
> power supply, and my Kill-a-Watt meter says 14 watts whether it's on or
> off. Is the meter likely to be that far off, or is something else at
> work? For other devices (SB2, SB3, NAS) it reports wattage close to
> what others report, but for some reason my Boom readings are much
> higher. Ideas?
>
>
> --
> aubuti
> ------------------------------------------------------------------------
> aubuti's Profile: http://forums.slimdevices.com/member.php?userid=2074
> View this thread: http://forums.slimdevices.com/showthread.php?t=51667
>
>

Zaragon
2008-09-06, 12:48
Hi All, Do not use Lithium (Li-Ion or Li-Po) batteries on Boom! They can
EXPLODE. Seriously. Warranty is one thing, but explosions are something
else all together.

With Boom, there is a high inrush current, that can damage Li-Ion packs
too.

Of course, when battery packs are used with the products they are designed
for, all the safety considerations have been taken care of by the
manufacturer. But using a Lithium pack outside of its designed product can
be really bad.

-Caleb




Whilst I agree with the sentiment that you have to be careful with Lithium batteries, particularly LiPo the current capability is a function of the pack design not inherent in the technology. I'm aware of LiPo packs that can easily supply 20C+ so 90-100A sustained is not particulary a problem. I don't think the boom is likely to require quite that much unless you short the power input.

A 3 cell LiPo would be ideal and quite light. The only problem is sticking within the cell parameters which means watching the discharge voltage and charging properly. Needs to be professionally produced though for general usage.

For anyone thinking of trying out Lithium batteries there are some spectacular videos on Youtube for some LiPo packs which are deliberately abused to show what can happen if you don't take care of your packs.

Here is a couple of links to show what happens when you deliberately overcharge a pack and bear in mind that once a pack is damaged it can happen at any time.

http://www.youtube.com/watch?v=KpUXuEg3fNE
http://www.youtube.com/watch?v=SQ0SNESIkWk

I'd suggest if you don't really know what you are doing and want to try batteries stick with lead-acid, NiCad or NiMh (Nickle Metal Hydride) just don't exceed the current draw/charge levels.

pippin
2008-09-06, 13:13
Hi All, Do not use Lithium (Li-Ion or Li-Po) batteries on Boom! They can
EXPLODE. Seriously. Warranty is one thing, but explosions are something
else all together.

With Boom, there is a high inrush current, that can damage Li-Ion packs
too.

Of course, when battery packs are used with the products they are designed
for, all the safety considerations have been taken care of by the
manufacturer. But using a Lithium pack outside of its designed product can
be really bad.

-Caleb




On Sat, Sep 6, 2008 at 10:05 AM, pippin <
pippin.3fbsqn1220721003 (AT) no-mx (DOT) forums.slimdevices.com> wrote:

>
> SuperQ, was the before or behind the power adapter?
> With the Laptop battery I will not need a power adapter, it's already
> 15VDC
> And the battery I think about using (the small one at 4100mAh) is not
> new but almost unused, used to be my backup battery... I'll give it a
> try once I find the pinout.
>
>
> --
> pippin
>
> ---
> see iPeng at penguinlovesmusic.com
> ------------------------------------------------------------------------
> pippin's Profile: http://forums.slimdevices.com/member.php?userid=13777
> View this thread: http://forums.slimdevices.com/showthread.php?t=51667
>
>
Well, I don't actually plan to CHARGE them.
The power drain should be much lower than with my notebook, which is rated at up to 2.6A
Would it help if I shortcut the power line with a big capacitor?

ccrome2
2008-09-06, 13:40
On Sat, Sep 6, 2008 at 1:13 PM, pippin <
pippin.3fc1az1220732103 (AT) no-mx (DOT) forums.slimdevices.com> wrote:

> Well, I don't actually plan to CHARGE them.
> The power drain should be much lower than with my notebook, which is
> rated at up to 2.6A
> Would it help if I shortcut the power line with a big capacitor?
>

No, that's the main problem. Boom has large capacitors inside, which causes
a high (> 30 A) inrush current when first plugging in. Max current is about
2.5A during normal use. It's the inrush that can cause problems.

pippin
2008-09-06, 14:03
On Sat, Sep 6, 2008 at 1:13 PM, pippin <
pippin.3fc1az1220732103 (AT) no-mx (DOT) forums.slimdevices.com> wrote:

> Well, I don't actually plan to CHARGE them.
> The power drain should be much lower than with my notebook, which is
> rated at up to 2.6A
> Would it help if I shortcut the power line with a big capacitor?
>

No, that's the main problem. Boom has large capacitors inside, which causes
a high (> 30 A) inrush current when first plugging in. Max current is about
2.5A during normal use. It's the inrush that can cause problems.
OK, so what about an inline inductor? Not enough?
An NTC?

SuperQ
2008-09-06, 14:06
No, that's the main problem. Boom has large capacitors inside, which causes
a high (> 30 A) inrush current when first plugging in. Max current is about
2.5A during normal use. It's the inrush that can cause problems.

Yea, 30A should be no problem for many LiPo packs. A 5Ah pack rated for 20C used in R/C planes can handle 100A continuous.

You still need low voltage protection, and a charge controller. It may still be cheaper to use sub C or similar NiMH packs.

Michaelwagner
2008-09-07, 04:33
Boom has large capacitors inside, which causes a high (> 30 A) inrush current when first plugging in. Max current is about 2.5A during normal use. It's the inrush that can cause problems.

Fools rush in,
where wise men never go,
but wise men never fall in love,
so how are they to know?

pounce
2008-09-07, 09:57
I use a small computer backups (UPS) for lots of ghetto portability. Ultimately flexible since you can plug any AC item into it. Downside obviously is that they are heavy.... but with great power comes.....

autopilot
2009-04-24, 02:03
Could someone please summarise the situation regarding using a laptop/power pack/etc please.

Bit's of information floating around and i realise it invalidates the warranty, but is anyone successfully doing this right now? If so, could they please post concise details/guide to exactly what they did and what they use. Thanks :)

pippin
2009-04-24, 02:30
Could someone please summarise the situation regarding using a laptop/power pack/etc please.

Bit's of information floating around and i realise it invalidates the warranty, but is anyone successfully doing this right now? If so, could they please post concise details/guide to exactly what they did and what they use. Thanks :)

I have used it a few times with a LiIon battery pack.
Caleb warned that this is EXTREMELY dangerous (battery pack can actually explode) but so far it works fine :-)
Never tried it for more than a few hours but I feel it works quite long.
http://forums.slimdevices.com/showpost.php?p=337466&postcount=23

Edit: Just saw your other post: Yes, it gives me about 5-6h playback (not with the battery shown, I've got another, double sized one. In fact I've got three of those which will give me about a day of playback, but as I said: I never did THAT).