Problems with Bottlebatt

[Chris Adams]

Hi All,

I received my Bottlebatt on Monday and it is an improvement on the standard power supply in all respects.

However, I'm having a problem.  I have had the same issue as Grainger with the S/PDIF input from my transport from day one.  That clipped, distorted sound that to me sounds like undersampling rather than oversampling. It has happened a few times and turning the input switch through all the inputs and back to S/PDIF took care of the problem.  The day I got the Bottlebatt, I hooked it up and put it on BAT CHG which charges the battery and runs power to the dac so you can listen.  I left it this way for about six hours and listened for an hour and change that night with the Bottlebatt on BAT ONLY.  Beautiful.  I left it on BAT CHG over night and all day Tuesday and listened for an hour and change that night on BAT ONLY. Again, beautiful. Friday I sat down to listen on BAT ONLY and after the first disc stopped I began to hear a thumping. Not low pitched, about low mid . . . maybe 500hz.  It was thumping at about 120 beats a minute.  Not knowing what it was I changed out everything but the dac, one piece at a time.  Turned out to be the dac.  I put on some music and absolutely no sound.  I power cycled it and no sound.  I turned the input selector all the way left and back to S/PIDF and got the clipped, distorted sound.  Turned the Bottlebatt to BAT CHG and all is well.  Left the Bottlebatt on BAT CHG until tonight, two days.  Listened for about 35 minutes and got the clipped, distorted sound in the middle of a song.  Stopped the disc and heard the thumping.  Turned the Bottlebatt to BAT CHG and clear sound.  I just left the listening room with the Bottlebatt on CHG ONLY.  I'm thinking the battery was not fully charged but after not using the dac for two days and having it run only 35 minutes before distorting seems odd.  I don't want to shut down the dac to charge the battery every time I finish listening.  The dac does sound better left on and takes a while to settle in when it has been off.  Any thoughts would be appreciated.

[Doc B.]

Sounds like the battery is not taking a full charge. I think we'd better issue a call tag for it and check it out for you.

[Chris Adams]

Thanks.  Just for your info, I let it charge all night and checked the voltage. Only 6v.

[Doc B.]

For what it's worth Josh put a Bottlebatt with a battery from the same batch as yours online today around 9:30 and it's still running our DAC just fine at 3:45. We now have a good baseline to compare to when your supply arrives, in order to help us sort out just what is going on.

[jake111]

Mine has an issue too. I have only ever used the USB connection to the DAC. Today after overnight CHG only, the DAC quits after 2.5 hours of BAT only. I checked the voltage and it was 3.84v. I'll check the voltage tomorrow after CHG only all night.
Thanks, Jess

[Doc B.]

Yes the DAC quits when the 6V battery discharges to around 3.9V. We got 12 hours out of a battery from the same batch as those shipped and now have a several hours on another from the same batch. I'll suggest you run the DAC on BAT/CHG for a few days to let the battery really get a deep charge, then try again on BAT ONLY see how long it lasts.

[Paul Birkeland]

Mine has an issue too. I have only ever used the USB connection to the DAC. Today after overnight CHG only, the DAC quits after 2.5 hours of BAT only. I checked the voltage and it was 3.84v. I'll check the voltage tomorrow after CHG only all night.
Thanks, Jess

Does the red LED glow when you're on the charge setting?  At 3.84V, on charge, the LED will glow quite visibly.

[jake111]

Yes, the charge light works. Been charging for 30hrs and it's at 6.8v. I have it on CHG ONLY since BAT CHG only got it up to 5.8v in 25hrs without use.

So, what's the reason for only a 6v battery?  Just curious.

[Doc B.]

I'm not sure I understand the question. The battery is to supply more clean power than the line lump. It is 6V because the DAC needs 6V to feed the regulators. If your battery has charged to 6.8V it should be ready to run for 7-8 hours, which is what we estimate for average run time.

[Paul Birkeland]

Yes, the charge light works. Been charging for 30hrs and it's at 6.8v.

That's excellent, and super topped off.

I have it on CHG ONLY since BAT CHG only got it up to 5.8v in 25hrs without use.

The charge is intentionally slow, the idea here is to use the middle switch positioning for casual listening, and the battery position for intense listening sessions.  There isn't anything wrong with running the DAC with the switch position in the middle and 5.8V available.  Slow trickle charging will give your battery a nice, long life. 

So, what's the reason for only a 6v battery?  Just curious.

A 12V battery of the same size would run for half as long and produce more than twice as much heat in the regulators inside the DAC, as well as requiring a different line lump power supply for charging.

[mcandmar]

The 3.8v cutoff makes sense as most 3.3v regulators need .5v headroom before they drop out, but does the USB interface continue to operate down to these voltage levels?

[Paul Birkeland]

The 3.8v cutoff makes sense as most 3.3v regulators need .5v headroom before they drop out, but does the USB interface continue to operate down to these voltage levels?

The point is being missed a little bit here.  Running the fully charged battery down to 3.8V is going to take in excess of 12 hours.  This is not the intended use of this product.  We intended it to be run on the battery only from 4-8 hours, then to sit on the charge only or battery/charge cycle for long periods of time.  Running the battery down to 3.8V repeatedly is only going to result in premature battery wear and very long charge times.

[mcandmar]

Ahh ok, that makes more sense. 8 hours run time will be more than enough for me.

[Doc B.]

The point is being missed a little bit here.  Running the fully charged battery down to 3.8V is going to take in excess of 12 hours.  This is not the intended use of this product.  We intended it to be run on the battery only from 4-8 hours, then to sit on the charge only or battery/charge cycle for long periods of time.  Running the battery down to 3.8V repeatedly is only going to result in premature battery wear and very long charge times.

Yes, and I pointed this out yesterday, but we seem to be generating multiple threads on the same subject. It's not an iPhone and it's not intended that you carry it in your pocket all day and only plug it in after you exhaust it. The BAT only mode is really just there for critical listening and we were pleased to find that BAT/CHG seems to perform just about as well, both being an improvement over using the stock line lump alone.

http://bottlehead.com/smf/index.php?topic=7975.msg81328#msg81328

[jake111]

Ok, thanks for the explanations. I just assumed that since the DAC says 9v, that's what it would require from the battery.

Now with a 6.24v full charge I got 3hrs on BAT ONLY before it quit. I'll leave it charge till Monday and maybe it'll get better.