Battery power supplies for the Regen

[fob69]

Having deluged this thread with perhaps too much information about the care and maintenance of batteries, and despite my comfort with using LiPo batteries, I've been pursuing mmerrill99's suggestion of using LiFePO4 batteries instead.

 

I've spent several hours looking for a convenient 6.4V LiFePO4 battery pack, where the individual cells in the series-wired pack are not simply protected, together as a unit, from excessive charge or discharge voltages, but are also kept in a balanced state, while charging with a simple, semi-intelligent, two-wire charger - again, with the understanding that balance charging can greatly extend the service life of the pack by avoiding the situation where one weak cell gets weaker still, eventually spoiling the entire pack.

 

There are lots of LiFePO4 packs that have built-in protection circuits, but very few of them include balance charging modules inside the pack itself.

 

This 6.4V 4500mAH LiFePO4 pack by Tenergy, a company that has a great reputation in the battery industry, appears to have everything we could want in terms of easy use, with proper self-management of its cells:

 

 

[ATTACH=CONFIG]26878[/ATTACH]

 

Tenergy LIFEPO4 6.4V 4.5Ah Pack - Item #31949

 

http://www.tenergy.com/31949

 

https://www.amazon.com/Tenergy-4-5Ah-LiFePO4-Rechargeable-Battery/dp/B00CPTCCPK

 

(This $39.99 Amazon price is a really good deal, as most places sell it for $69.99)

 

 

And here's the matching charger:

 

[ATTACH=CONFIG]26879[/ATTACH] [ATTACH=CONFIG]26880[/ATTACH]

 

Tenergy 6.4V (2-Cell) Intelligent 1A LiFePO4 Battery Pack Charger - Item #01369

 

http://www.tenergy.com/01369

 

Amazon doesn't carry it. (Why not?)

 

Search Google Shopping: https://www.google.com/search?output=search&tbm=shop&q=tenergy+01369&oq=tenergy+01369

 

----

 

Here are some noteworthy specs for the battery:

 

Nominal Capacity: 4.6Ah (typ.), 4.5Ah (min.)

Nominal Voltage: 6.4V

Max. Discharge Current (Pulse): 8.0A

Discharge Method-Standard: 900mA

Max. Continuous Discharge: 5.0A

Discharge Cut-off Voltage: 4.6V

Battery Dimension: 70x47x101mm (It's about 4-inches tall)

 

I will add that, when fully charged, it can yield no more than 3.33V per cell or 6.67V, but will drop quickly to 3.2V per cell (6.4V) where it will stay throughout most of its discharge. The protection module will shut down the pack at 4.6V (2.3V per cell), but a USB Regen that has to provide 5V power to a DAC will fail before you can get down to 4.6V. If the USB Regen is not supplying 5V power to a DAC, then this battery will shut down before failing to satisfy the Regen's 3.3V regulator (which probably wants to see a little more than 3.3V, anyway, but probably doesn't need as much as 4.6V.)

 

So there you go... Now who wants to be first to give it a listen? :-)

 

By the way, you cannot combine these in series to achieve a higher voltage. If you want a different voltage, Tenergy has the following, similar products from which to choose:

 

Lithium Iron Phosphate

 

Mike

 

Hello

 

I bougth the same battery in an other brand : http://www.all-batteries.fr/batterie-lithium-fer-phosphate-un38-3-6v-4-5ah-t1-aml9142.html

 

It seams to be a perfect deal.

 

I bougth a lead battery charger given for 6v (i check it outputs 6,8v).

Did i make a mistake ? I did not found specific 6,4v lifepo4 charger ...

 

I need 5v outpu, so I bought a tps lineat regulator TPS7A4700 on ebay noise < 40 microV.

Is ther a risk to damage the regulator if the voltage comes under 6v ?

Do you know if such a regulator will change the battery output impedance ?

 

 

About to unplug the battery during the play :

I check and loader redistance is not infinite whrn it is unplugged. The loader should be disconected from the battery, otherwise there will be DC leakage am i right ?

 

Do disconet it, i should disconnect both wires except if charger is unplugged from the wall ?

 

Thank you for your help

 

Bernard

 

 

 

Sent from my iPhone using Computer Audiophile

 

Tplink optical bridge/etalon streamer/audiogd nfb29/linn klout/athom sirrocco + athom rafale v38 hypex

[zilch0md]

Hello

 

I bougth the same battery in an other brand : Batterie lithium fer phosphate UN38.3 6V 4.5Ah T1 - AML9142 | All-batteries.fr

 

It seams to be a perfect deal.

 

I bougth a lead battery charger given for 6v (i check it outputs 6,8v).

Did i make a mistake ? I did not found specific 6,4v lifepo4 charger ...

 

I need 5v outpu, so I bought a tps lineat regulator TPS7A4700 on ebay noise < 40 microV.

Is ther a risk to damage the regulator if the voltage comes under 6v ?

Do you know if such a regulator will change the battery output impedance ?

 

 

About to unplug the battery during the play :

I check and loader redistance is not infinite whrn it is unplugged. The loader should be disconected from the battery, otherwise there will be DC leakage am i right ?

 

Do disconet it, i should disconnect both wires except if charger is unplugged from the wall ?

 

Thank you for your help

 

Bernard

 

 

 

Sent from my iPhone using Computer Audiophile

 

Tplink optical bridge/etalon streamer/audiogd nfb29/linn klout/athom sirrocco + athom rafale v38 hypex

 

Please, do not use that lead-acid battery charger with your LiFePO4 battery. That's dangerous. You could start a fire using that charger.

 

The same vendor who sells your battery offers this 1.3A smart charger for 2-cell LiFePO4 chemistry:

 

Chargeur Lithium-ion pour 7.4V (Pack 2S) 1.3A - CEL5101 | All-batteries.fr

 

---

 

As I had written in the post you quoted, a two-cell LiFePO4 battery has a nominal rating of 3.2V per cell (6.4V total) but when fully charged, they can be as high as 3.33V per cell (or 6.67V total). When discharging under a load, the battery's protection module will shut down the pack at 4.6V total (2.3V per cell).

 

If you need 5V for the USB Regen, because you are powering a DAC via the USB Regen's 5V regulator, you can just connect the battery directly to the USB Regen, allowing the USB Regen's built-in voltage regulator (which is low-noise, state-of-the-art), to shut down when the battery voltage becomes too low. You will not hurt the built-in regulator by under-powering it and you do not need to insert an external voltage regulator into the power line - this would only create more noise.

 

You only have to disconnect one of the battery leads to prevent discharge.

 

Mike

[fob69]

Hi mike. The problem is that i supply an etalon player, not a regen, and i don't know if it is voltage regulated. I have a big doubt because it is written in bold on the resseller website not to supply the etalon more than 5v ...

 

Bernard

 

Sent from my iPhone using Computer Audiophile

 

Tplink optical bridge/etalon streamer/audiogd nfb29/linn klout/athom sirrocco + athom rafale v38 hypex

[fob69]

Etalon input is regulated. 6,6V is ok

 

 

Sent from my iPhone using Computer Audiophile

 

Tplink optical bridge/etalon streamer/audiogd nfb29/linn klout/athom sirrocco + athom rafale v38 hypex

[zilch0md]

Oh, that's good, then. All you need is the right charger for your battery.

[fob69]

The 6,6v lifepo4 battery i have has a iner low voltage / over charge management. It cut the battery at 5,3v and cut the load at 6,6. This is good because you juste have to provide a right voltage and current tu load it, but the problem is tha the usual loaders won't detect it is loaded.

 

The cheap lead charger i bougth works very well with it (6,8v), but stays in "load" mode when it reach 6,6v. If i unplug ang plug the loader, it then detect it is loaded. I cannot manage the hysteresis)

 

So two solutions :

- a timer

- a relay switch that cut the load at a fixed voktage (ex : 6,5v).

 

I am looking for a not so complicated electronic kit to do it.... any suggedt ?

 

The sound on my etalon is increadibly good with this supply. For the price (15$), it is a must.

 

I will buy an other on for my tplink.

 

 

Sent from my iPhone using Computer Audiophile

 

Tplink optical bridge/etalon streamer/audiogd nfb29/linn klout/athom sirrocco + athom rafale v38 hypex

[fob69]

http://www.all-battery.com/TenergyLiFePO4BatteryCharger-01369.aspx

 

 

Sent from my iPhone using Computer Audiophile

 

Tplink optical bridge/etalon streamer/audiogd nfb29/linn klout/athom sirrocco + athom rafale v38 hypex

[YashN]

I'm no stranger to odd things--heck the entire operating principal of the REGEN was considered odd or ridiculous to many (still is to some) when it first came out--but it would be a long time before I'd buy into the notion that the chemicals of a battery form and discharge differently depending upon the noise and spectra of what charged them.

 

I indeed read of such an odd thing using the repeated discharge of inductors to recharge a battery, the findings were very odd indeed.

[Cornan]

I indeed read of such an odd thing using the repeated discharge of inductors to recharge a battery, the findings were very odd indeed.

Personally, odd things makes me very curious. I have been curious if clean power makes a difference when charging a battery. So..what type of odd things came out of those findings?

I am sure there is something more that could be done to optimize battery charging or even make the battery supply cleaner!

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[ElviaCaprice]

Never mind, nobody likes a SA.

I still find that the single cell Lifepo4 battery the best solution to the Regen. Bypass the 5V vbus. Has anyone compared using this DIY with a LPS-1 instead?

Seems like an expensive solution the LPS-1, when the Lifepo4 battery and switching power supply for charger we're less than $30.

[Cornan]

I find If I wash my hands before plugging in the charger, to help.

Might be better if you keep your hands off!

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[YashN]

Personally, odd things makes me very curious. I have been curious if clean power makes a difference when charging a battery. So..what type of odd things came out of those findings?

I am sure there is something more that could be done to optimize battery charging or even make the battery supply cleaner!

 

The charge cycle and behaviour of the batteries were different than with a normal means of charging.

 

NB: this wasn't a 'clean' power in the Audiophile sense at all.

[sandyk]

I indeed read of such an odd thing using the repeated discharge of inductors to recharge a battery, the findings were very odd indeed.

 

You can get quite a high voltage from the "back EMF" of an inductor.

In the old Step by Step analogue Telephone Exchanges which typically used -52V supplies, the Signalling relays could develop a back EMF as high as 800V when the circuit was opened during 10 I.P.S dialling ! (monitoring those circuits caused my hearing damage)

The back EMF from a Motor UniSelector was very painful with it's higher current demands if you weren't careful.

Another example is the Kettering car ignition system where you may develop as high as 30KV from a 12V ignition coil.

[YashN]

You can get quite a high voltage from the "back EMF" of an inductor.

 

Absolutely, and that's the whole point of what I was reading at the time.

 

Thing is, for audiophile purposes, does such a power supply cause RFI or EMI that affects SQ, just as switching PSUs do? It appears the basis of operation is similar if not the same. I have not much knowledge of SMPSes, so I don't know.

 

Just think about this back EMF for a minute: most of our circuits seem to use the less efficient energy generated rather than this one... or am I incorrect here?