Cheapo Battery Management System

[Saturnus]

Originally Posted by jkeny

I'd be interested in your impressions of these batteries powering the Tripath amp as this is my next step - I have a TA2020 amp that my transformer output DAC is DC connected to - sounds excellent with SMPS 12V power - will be trying a Salas shunt reg & then the batteries.

In my opinion a battery supply is superior. It's like on some live recordings the music gets more relaxed and stop being a concert but becomes an evening with guys jamming. With a SLA battery the bass may at times seem hesistant (but still better than on a grid powered power supply) but with the LFPs it has perfect timing and appears endlessly deep.

[jkeny]

I just found these battery management ICs specifically for LiFePO4 batterries - MCP73123 - available in Mouser $1.50. Has anybody used them or got any spare to send me?

[alain_online]

Hi Jkenny,
I'm also searching for a simple charger for a Hyperion LiFePO4 battery powering the digital part an ESI Juli@ soundcard.
Are you using HyperionA123 batteries ?
For these, I'm afraid MCP73123 would not be adequate, as the standard charge methods are:
1100mAh: 1.5A to 3.6V CCCV, 45 min.
2300mAh: 3.0A to 3.6V CCCV, 45 min.
and MCP73123 is limited to 1100 mA.
Not 100% shure, but CCCV is CC and CV charging (CC first, and, as as charge goes on, the current charge is then voltage limited). A L200 regulator can do that, except swithing off after 45 min.
For SLAs, it's better to charge it individually; do not know for LiFePO4, but can't be wrong doing it.
Best regards,
Alain

[jkeny]

Alain,
You seem to be correct, I overlooked the specs on these but should have noted that they are meant for mobile devices so probably limited current.

Here's a cheap single charger for $13.75 which seems to suit - only problem is shipping is US only http://www.all-battery.com/tenergyli...rger01300.aspx I've too many things to DIY & an off-the-shelf solution appeals to me now.

Yes, I have the Hyperion A123 2.3Ah batteries (good prices). Individual charging is recommended - all the muti-cell chargers have balancing circuits to protect individual cells from overcharge (>3.7V) damage, so my simple approach would be to charge individually but in parallel.

Where are you using your batteries & with what result? I'm only starting to use mine so too early to give any feedback but I intend to power a ESS Sabre32 DAC with some of these. First, I'm experimenting with them on powering a Musiland USB DAC pcb & ESS 2 channel Vout DAC as well as a Tripath (TA2020) amp.

[alain_online]

Jkenny,
My little experience with batteries are with tube heaters, Fertin's driver field coil and for cathode bias. Except for the last on, I liked the result more than the on I had before. Just subjectively cleaner, looking deeper in music; not tested anything.
Now, I have not yet powered the Juli@ soundcard, so I can't tell anything about it. I'm using it with cMP PC audio setup, with I2S to Sabre DAC.
On my to do list about batteries: power my Sabre DAC and the computer.
For monitoring discharge, I found a little voltage comparator, which seems simple to implement (see: "simple comparator" in application notes) : LM139.
Best regards,
Alain

[calypso]

we all need the poor man solution! is there someone who arranged to feed a ta2020 with a li-ion notebook battery?
do you think it may be possible to use a 60W step up converter boosting a 7.2v to 14.4v with a ta2020 amp?
they're rated from 5000 to 10000 mah... and the only expense would be the converter and a low battery alarm.