Develop ultra capacitor power supply and LiFePO4 battery power supply

Hi there.

Let me ask you a question.

The thread title announces an ultracap supply. Why has this project turned into a battery supply project? Did I miss something?

I thought Ian even confirmed when we were having the discussions around the best-of-all-options some time back that a supercap supply would be No.1 choice !?!?

Thx.[/QUOTE
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Hi Claus!
You did not miss a thing.
Ian started to put the 123 first on the road. Some of the reasons were:

He had a long-time-experiance in useing those batteries and an extended state of development at the start of the thread. Eventually he would continue refining and finish the Ultra C solution.

In most setups both powering systems could be needed.
The 123 batt. are meant for 3.3Volts + multiples while the U Capacitor system aims for 2.5 volts and its multiples.

Ed
 
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@Ed Linssen,

I don't believe Ultracaps are at all limited to multiples of 2.5V. In my experience, they still work well when run at voltages under their max (typically but not always 2.7V).

I suspect they will work BEST in some range above 0V and below their max voltage, say 1.5V - 2.5V each. BUT I don't know that and I could easily be wrong here.

I DO believe that for reasons of safety and Ultracap longevity, you want to stay a couple tenths of a volt below their rated maximum... say 2.5V max for a 2.7V rated Ultracap.

BUT you can string together a series set of Ultracaps with appropriate balancing circuitry (see datasheets) and get a variety of output voltages.

I have 3 of Ian's UCPi setups and regularly use them at either 3.3V each or 5V each.

I suspect @Soundcheck inquired as he recently tried the new Allo Shanti and had some very positive things to say about it. That dual 5V supply has a 2-Ultracap series string of 1.5F Ultracaps as the final element in each rail. They do some very good things there and are IMHO a large part of the sonics one gets from the Shanti.

OTOH, I'm comparing a slightly-modified Shanti to a pair of Ian's UCPi charged to 5V powering an Allo Katana. IF a pair of 1.5F Ultracaps per rail provide positive benefits in that supply, imagine what a pair of 350F Ultracps per rail in Ian's UCPi does! BUT these and my associated charging string cost MUCH more than the Shanti for those additional benefits.

I'm curious where Ian is on his Ultracap supply too. Over the years, I have learned that Ian will announce when he is ready. AND those announcements are well worth waiting for!

Greg in Mississippi
 
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Hi Greg,
Depending from make Uc's vary globally from 2.3V to 2.7Volts. Going higher than the max will short lifespan.
No problem staying lower than the max.
What I understood from one of Ian's first posts was that he was aiming for a safe average of about 2.5V steps for his to develop Uc's supplies as an easy way to make 5, 10, 15 volt steps.
Anyway this is what I understood from his writing, but I am shure he can help us out with his real reasons.
And of course you yourself can do as you like and charge the C's with any voltage you like or need, as long as you keep a safe margin and not charge higher than the max per C.
Ed
 
Look folks.

A non-regulated supercap supply with 2 x 2,7V caps in series can deliver any voltage between 0 and 5.4V.

The output voltage solely depends on the charging voltage.
By introducing a flexible charging voltage you can run whatever
voltage up to 5.4V.

This approach is as flexible as a supply can get. And IMO much better than any battery supply.

BUT. It all this needs some logic.

* You need to wait until the caps are charged to a certain threshold
* The charging current must be higher then the discharging current
* You need a turn-off mechanism on the DC side (cut off DC-load -> turn on discharge-R)
 
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Ian,

Last night I soldered all the batteries into my four LiPo4 supplies, tested them and everything worked fine first go. Excellent! Thank-you.

So I am sitting there thinking about my next project which are some DHT preamps trialling a number of tubes operating at B+ between 100Vdc and 200Vdc. If I series connected my four battery supplies together I would have 150Vdc, which would be great for the breadboarding stage of that project. Can you see any issues with me series connecting these supplies to reach that sort of voltage?

Who knows, I might like the sound of battery B+?

Anthony
Anthony
 
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@acg,

You are a very brave soul. OTOH, I am looking at my 2 Ian LiFePO4 supplies and thinking I can use both with each side of the board in series to give me 4 16.5V floating supplies for the 2 EUVL SEN I/V boards I have here for Ian's DM 9038Q2M DAC duties... and use 2-6 UCPi for the FiFoPi and DAC boards, with anything from 1 UCPi each to 3 powering the key areas of each board.

Or get 2 more boards to get 2 +-33V supplies for an OPC N1DT I/V setup.

As I understand it, Ian's boards monitor the voltage on each of the cells separately so that when the first cell reached the low-voltage limit, it would cause all 4 ganged boards to turn off and start recharging. That would let it work safely and without damaging any cells through over-discharging, though you'd likely want to time how long that takes and be ready to power down the rest of your system (or at least the amp) before preamp powers-down.

AND recently doing a lot of listening to both Ian's GB setups using his LiFePO4 supply and an Allo Katana using either 2 5V-charged UCPi or an Allo Shanti (which has 2 1.5F Ultracaps in series at the output of each of its 5V rails), I think you'd like that battery B+ very much!

What current draw do you expect with this setup?

Greg in Mississippi
 
@Greg Stewart

I purchased the LiPo4 boards for a few reasons, none of which had anything to do with tube gear. At the time I was thinking about SS preamplifiers and phonostages and I will still trial the supplies in that gear which looks for anything up to a bipolar 20V.

In the DHT tube preamplifier, depending on the tube I use, B+ current should only be 20mA - 35mA per channel, with one tube option capable of a whopping 85mA at low voltage (160V).

If I trialled these batteries in the tube phonostage then B+ is about 150V and the total current draw of all four tubes is 70mA, or 35mA per channel.

I figure that with the four LiPo4 supplies I have here I can get somewhere close to 150V, assuming it is safe to do so, and can trial and measure and listen to one channel to determine if it is worthwhile. What I don't know is if the relays and caps and any other things on the lipo boards will see this high voltage and if they are rated to carry it.

Anthony
 
Hi to all
I would like to remotely control my LiFePO4 board to turn it on (and off) using a signal on J15 jumper.
From the manual I understand that I have to use PIN 1 and 2.
Ma question is: may I use another power supply to turn on this one? If I use +5v where do I have to connect ? To pin2 and so 0V to pin1?
 
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@paoloilpizzo,

The manual specified 3.3V-3.6V on J15 pins 1 & 2 to turn the unit on, bipolar (so either polarity ok). You can use your +5V supply, but you need to drop it down to the allowable voltage level. I'd suggest using a small cheapo 3.3V regulator for that purpose.

The manual doesn't state what will happen if you feed it 5V there, but in many cases that will damage that input, so you don't want to do that.

Greg in Mississippi

Greg
 
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@paoloilpizzo,

As I said above, pins 1 & 2 are bipolar so you can connect them in either polarity.

OTOH, while I understand that @neilsek has it working with a 5V input, I still suggest regulating down to 3.3V, especially if your 5V is not well regulated to 5V.

Ian is a great guy and will likely help you out if you burn that input with a 5V input that drifts up to 5.5V or 6V, but why go there?

My 2 cents.

Greg in Mississippi
 
@paoloilpizzo,



As I said above, pins 1 & 2 are bipolar so you can connect them in either polarity.



OTOH, while I understand that @neilsek has it working with a 5V input, I still suggest regulating down to 3.3V, especially if your 5V is not well regulated to 5V.



Ian is a great guy and will likely help you out if you burn that input with a 5V input that drifts up to 5.5V or 6V, but why go there?



My 2 cents.



Greg in Mississippi



Thanks Greg. Because I want to use an ATX power supply (to power another raspberry and an external HDD) I will use the 3.3V output.
 
Hi to all
I would like to remotely control my LiFePO4 board to turn it on (and off) using a signal on J15 jumper.
From the manual I understand that I have to use PIN 1 and 2.
Ma question is: may I use another power supply to turn on this one? If I use +5v where do I have to connect ? To pin2 and so 0V to pin1?

It says 3.3-6v. I've been using it effectively with 5v.

@paoloilpizzo,

As I said above, pins 1 & 2 are bipolar so you can connect them in either polarity.

OTOH, while I understand that @neilsek has it working with a 5V input, I still suggest regulating down to 3.3V, especially if your 5V is not well regulated to 5V.

Ian is a great guy and will likely help you out if you burn that input with a 5V input that drifts up to 5.5V or 6V, but why go there?

My 2 cents.

Greg in Mississippi

Thanks Greg. Because I want to use an ATX power supply (to power another raspberry and an external HDD) I will use the 3.3V output.

Thanks guys for your help. I'll double check the design principle later today to confirm if 5V is safe enough. I'll let you know.

Regards,
Ian
 
Hi to all
I would like to remotely control my LiFePO4 board to turn it on (and off) using a signal on J15 jumper.
From the manual I understand that I have to use PIN 1 and 2.
Ma question is: may I use another power supply to turn on this one? If I use +5v where do I have to connect ? To pin2 and so 0V to pin1?

Hi Paoloilpizzo,

Just checked up the schematic and design principle. I can confirm that it safe to use 5V to turn on the LifePO4 power supply.

Actually, internally it connects to an optical isolator diode with serial resistor. 3V to 6V are all with in working range. The polarity doesn't matter. And it's 100% isolated from the power supply.

So, please no worry. Go ahead with your configuration.

Regards,
Ian
 
I set up today one of my Lifepo4 MKII boards for 13,2V configuration. Before I used it only for 2x3.3V, now added 13,2V.
When testing with multimeter J3&J4, it starts from 4,xV and drops down to 0V.
All the batteries and holders are OK and show 3,25V, either with ON or OFF, testing from the board (underside).
When testing -BT10/+BT8 and -BT4/+BT1 multimeter shows 9,9V. But when measuring -BT2/+BT8 and -BT5/+BT1 I get down to zero (same as J3/J4).
What should I test next to find a solution?
 
Carefully check the connection of (-)BT1 and (-)BT8. Many of us have had a problem with a barely elevated plastic in the center of the negative terminal causing discontinuity. In off mode the batteries are all in parallel so all the measurements on the underside will be +3.25V, even if one of the batteries is not connecting.
 
Thanks alazira
The connections are rigid, checked also with ohmmeter, also from battery holders.
The last three rows are working correctly to my understanding and they provide 9,9V. But when measuring with the second row, it does not provide expected 13,2V.

Carefully check the connection of (-)BT1 and (-)BT8. Many of us have had a problem with a barely elevated plastic in the center of the negative terminal causing discontinuity. In off mode the batteries are all in parallel so all the measurements on the underside will be +3.25V, even if one of the batteries is not connecting.
 
Thanks alazira
The connections are rigid, checked also with ohmmeter, also from battery holders.
The last three rows are working correctly to my understanding and they provide 9,9V. But when measuring with the second row, it does not provide expected 13,2V.

In [ON] mode, if (+)BT10 to (-)BT8 measures +9.9V and (+)BT2 to (-)BT8 doesn't measure 13.2V then there is probably a connection issue with BT2 as they should be connected in series in [ON] mode. Start systematically measuring from (+)BT2 to the (-) of the other batteries to determine where the problem is.