LOL... @pinnocchio, I took @Studey's question on gloves as referring to protection from the sharp edges on the cut tabs.
AND I did get a very minor scratch from mine that could have been much worse.
For cut protection, there are cut-resistant Kevlar gloves. Here in the US, we get them from our local hardware store.
AND @pinnocchio, I generally agree with what you said about shock protection. BUT when I was assembling the 325F Ultracaps for Ian's trial boards, a friend of mine who works in the industry and builds/handles Ultracap units on a daily basis cautioned me that they could kill. While I don't wear shock protection when working with either LiFePO4 cells or large value Ultracaps, I do treat the exposed terminals with extreme care.
Greg in Mississippi
P.S. Frightening people was my intention. As I said, I have built battery packs for almost 20 years and LiPo packs since they became available in the middle 2000's. Also building / debugging tube gear almost 30 years. AND I had more serious close calls in my LiFePO4 build than in all of that time. I thought it was going to be a quick and easy build based on my past experience. AND as each close call happened, I instituted another piece of protection/prevention that I hadn't realized I needed beforehand.
ALSO, do realize that at least in the US and Canada, it takes special training and certification to ship those cells and devices containing them. It's not too hard, I've been certified in the past for both these and explosive devices (in addition to model aircraft and helis, I also fly rockets and rocket-boosted gliders). BUT it is not something you want to do without that training and certification... both from a hazard perspective and the trouble you'll get into.
AND I did get a very minor scratch from mine that could have been much worse.
For cut protection, there are cut-resistant Kevlar gloves. Here in the US, we get them from our local hardware store.
AND @pinnocchio, I generally agree with what you said about shock protection. BUT when I was assembling the 325F Ultracaps for Ian's trial boards, a friend of mine who works in the industry and builds/handles Ultracap units on a daily basis cautioned me that they could kill. While I don't wear shock protection when working with either LiFePO4 cells or large value Ultracaps, I do treat the exposed terminals with extreme care.
Greg in Mississippi
P.S. Frightening people was my intention. As I said, I have built battery packs for almost 20 years and LiPo packs since they became available in the middle 2000's. Also building / debugging tube gear almost 30 years. AND I had more serious close calls in my LiFePO4 build than in all of that time. I thought it was going to be a quick and easy build based on my past experience. AND as each close call happened, I instituted another piece of protection/prevention that I hadn't realized I needed beforehand.
ALSO, do realize that at least in the US and Canada, it takes special training and certification to ship those cells and devices containing them. It's not too hard, I've been certified in the past for both these and explosive devices (in addition to model aircraft and helis, I also fly rockets and rocket-boosted gliders). BUT it is not something you want to do without that training and certification... both from a hazard perspective and the trouble you'll get into.
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@Studley, got it. Thanks for that warning.
@misterdog, I would not bond the cells to the board, that will make removal for repair VERY difficult. The tabs on these are stout, so they make a VERY secure mounting of the cells to the boards.
@casshan, we would have to know more about your DAC to understand if this supply would work. We'd need to know what power rails it has with voltage and current for each. AND do understand this is not an 'Always On' supply. It is designed to be powered on when you are ready to listen or a bit beforehand to give it time to warm up, then listen for the time the batteries last. It will cut off when a lower cell voltage is reached if you have not turned it off before then and it recharges while off. This may or may not work with how you use your system.
Greg in Mississippi
@misterdog, I would not bond the cells to the board, that will make removal for repair VERY difficult. The tabs on these are stout, so they make a VERY secure mounting of the cells to the boards.
@casshan, we would have to know more about your DAC to understand if this supply would work. We'd need to know what power rails it has with voltage and current for each. AND do understand this is not an 'Always On' supply. It is designed to be powered on when you are ready to listen or a bit beforehand to give it time to warm up, then listen for the time the batteries last. It will cut off when a lower cell voltage is reached if you have not turned it off before then and it recharges while off. This may or may not work with how you use your system.
Greg in Mississippi
Default Tips on assembling and using the LiFePO4 Power Supply safely part 3
This is a very short part. The message here is that once you have assembled your cells to the boards, you now have a LOT of potential accidental short paths on both the top and the bottom of the board. SO you need to cover / insulate those areas.
You see in the pictures Ian posted of his that he mounted his boards to a wooden bass. This is an effective way to prevent most shorts on the bottom. Better would be to wrap a skirt of tape around the edges of the board or wedge in felt or foam to prevent anything from accidently getting dropped or pushed under the board and causing a short.
What I did was to make up a 4-ply piece of corrugated cardboard ply-cardboard (corrugation laid at 90-degrees to each other on each succeeding layer) to mount to the bottom of the LiFePO4 board.
Before I did that, I:
- Covered both sides with packing tape for some moisture resistance.
- Cut an airflow opening directly under where the large heatsink is on the top of the board AND made sure that area was totally covered in Kapton tape before mounting.
- Cut a recess for the remote communication cable socket on the bottom of the display / control sub-board.
I mounted the finished cardboard ply board right up against bottom of the LiFePO4 board, thinking the cut cell ends would cut into the board and allow it to lay flat. They did not, there is a little flex in my board, so I need to removed it and see where there are depressions, cut slots there, and remount at some point.
Because it is right against the bottom of the board most paths for shorts on the bottom are covered.
On the top, I wrapped Kapton tape across the ends of the cells to insulate them. Then I covered the top of each of the two rows of cells with packing tape so nothing can drop between them.
Others have suggested mounting the entire thing in a box, which is not a bad idea, but I suggest making sure you insulate the inside of the box where the bottom will mount with multiple layers of Kapton tape. AND make sure to allow for airflow.
You can see another taping routine in post #3236 of Ian asynchronous I2S and S/PDIF FIFO KIT group buy , but he did not fully cover the top, so you still can drop things between the cells.
However you do it, make sure to fully protect the bottom of the board and the top around the cells! This does not prevent ANY accidental shorts, but makes it much less likely they will happen.
I'll post some pics when mine is prettier. AND post your pics and ideas too!
Greg in Mississippi
This is a very short part. The message here is that once you have assembled your cells to the boards, you now have a LOT of potential accidental short paths on both the top and the bottom of the board. SO you need to cover / insulate those areas.
You see in the pictures Ian posted of his that he mounted his boards to a wooden bass. This is an effective way to prevent most shorts on the bottom. Better would be to wrap a skirt of tape around the edges of the board or wedge in felt or foam to prevent anything from accidently getting dropped or pushed under the board and causing a short.
What I did was to make up a 4-ply piece of corrugated cardboard ply-cardboard (corrugation laid at 90-degrees to each other on each succeeding layer) to mount to the bottom of the LiFePO4 board.
Before I did that, I:
- Covered both sides with packing tape for some moisture resistance.
- Cut an airflow opening directly under where the large heatsink is on the top of the board AND made sure that area was totally covered in Kapton tape before mounting.
- Cut a recess for the remote communication cable socket on the bottom of the display / control sub-board.
I mounted the finished cardboard ply board right up against bottom of the LiFePO4 board, thinking the cut cell ends would cut into the board and allow it to lay flat. They did not, there is a little flex in my board, so I need to removed it and see where there are depressions, cut slots there, and remount at some point.
Because it is right against the bottom of the board most paths for shorts on the bottom are covered.
On the top, I wrapped Kapton tape across the ends of the cells to insulate them. Then I covered the top of each of the two rows of cells with packing tape so nothing can drop between them.
Others have suggested mounting the entire thing in a box, which is not a bad idea, but I suggest making sure you insulate the inside of the box where the bottom will mount with multiple layers of Kapton tape. AND make sure to allow for airflow.
You can see another taping routine in post #3236 of Ian asynchronous I2S and S/PDIF FIFO KIT group buy , but he did not fully cover the top, so you still can drop things between the cells.
However you do it, make sure to fully protect the bottom of the board and the top around the cells! This does not prevent ANY accidental shorts, but makes it much less likely they will happen.
I'll post some pics when mine is prettier. AND post your pics and ideas too!
Greg in Mississippi
Hi @ian,
Today I assembled the lifepo4 battery power supply and everything seemed to be in working order. But the batteries kept on charging beyond the threshold of 3.35V. J4 and J3 read 14.61V and 14.51V instead of the expected 13.4V. I checked the batteries indivudally and there is one that has a reading below 3.35V. The other batteries have all a reading over 3.6V. The display shows charging 3.30V at 9.95A. I don't want to overcharge the batteries so I disconnected it from power. What can be wrong? Is the board faulty?
With regeards,
Big Bird.
Today I assembled the lifepo4 battery power supply and everything seemed to be in working order. But the batteries kept on charging beyond the threshold of 3.35V. J4 and J3 read 14.61V and 14.51V instead of the expected 13.4V. I checked the batteries indivudally and there is one that has a reading below 3.35V. The other batteries have all a reading over 3.6V. The display shows charging 3.30V at 9.95A. I don't want to overcharge the batteries so I disconnected it from power. What can be wrong? Is the board faulty?
With regeards,
Big Bird.
@big bird
Please set the ending charge voltage to the lowest number. The charger should be stopped in this case with OLED showing "Pending". Then read the voltage number from the OLED screen and let me know.
Please also make sure your multi meter is correct. The LiefePO4 board measurement was internally calibrated, should be accurate.
Regards,
Ian
Please set the ending charge voltage to the lowest number. The charger should be stopped in this case with OLED showing "Pending". Then read the voltage number from the OLED screen and let me know.
Please also make sure your multi meter is correct. The LiefePO4 board measurement was internally calibrated, should be accurate.
Regards,
Ian
@ian
I set the voltage to the lowest number of 3.25V. The charging starts pending and keeps pending up to 3.3V. Above 3.3V it starts charging according to the oled screen but the charging led is off.
The readings of the outputs are as follows (when the charging was pending at 3.25V):
J1: 3.69V
J2: 3.29V
J4: 14.75V
J3: 14.75V
J8: 5.089V
The voltage of the individual batteries are:
BT7: 3.290V
BT8: 3.696V
The others are all 3.698V
The voltage of the individual batteries increases again when the voltage is been set to 3.31V and higher except for BT7. That one stays at 3.290V.
With regards,
Big Bird.
I set the voltage to the lowest number of 3.25V. The charging starts pending and keeps pending up to 3.3V. Above 3.3V it starts charging according to the oled screen but the charging led is off.
The readings of the outputs are as follows (when the charging was pending at 3.25V):
J1: 3.69V
J2: 3.29V
J4: 14.75V
J3: 14.75V
J8: 5.089V
The voltage of the individual batteries are:
BT7: 3.290V
BT8: 3.696V
The others are all 3.698V
The voltage of the individual batteries increases again when the voltage is been set to 3.31V and higher except for BT7. That one stays at 3.290V.
With regards,
Big Bird.
It appears that BT7 does not get charged and stays at the initial voltage. I got 2 spare batteries and their initial voltage is 3.290V.
@Morde
Actually the threshold is 3V. The power supply will be shut down when the output voltage is lower than.
Thank you so much for finding a bug in the user's manual.
Regards,
Ian
Hi Ian,
But my LifePO4PowerSupply turn off when the J2 voltage is about 3.0V~3.1V and J1 is about 3.35V.
After I set "End charge voltage" to higher voltage, let J2 voltage is about 3.4V, and its stable now.
I assembled the 26650 cells on this board today and thought everything was fine, after a period of charging I tested the outputs and I am getting zero volts at J4 when there should be 13.2 or so.
The fuse F3 is good, so I'm at a loss to know why I have no juice at J4. Any suggestions on what to check are greatly appreciated, all other outputs measure the correct voltage except for J4.
Thanks very much in advance.
The fuse F3 is good, so I'm at a loss to know why I have no juice at J4. Any suggestions on what to check are greatly appreciated, all other outputs measure the correct voltage except for J4.
Thanks very much in advance.
Why not use the Prismatic pouch Cell to design a lifepo4 power supply? The pouch Cell has a larger capacity and can be used longer to charge, while the large capacity battery has a lower internal resistance of the pouch cell because the pouch cell does not need to connect more batteries for the large capacity.
I think we can buy a LiFePO4 module containing batteries from Taobao and then make a power supply by youself. It can ask for 3.3V or 12V. It has built-in protection and even short-circuit protection which Ian's board doesn't has this fuction. When the LiFePO4 module is low power, you can connect it to the DC of the relative voltage. The battery indicator is also very easy to buy.
Such as photos, such a battery module is only about 21 US dollars.
Those who know a little can also use the relay module to form a more complete charging and discharging architecture.
??12V?????????????YTX14 YTX7A????A123??-???
Such as photos, such a battery module is only about 21 US dollars.
Those who know a little can also use the relay module to form a more complete charging and discharging architecture.
??12V?????????????YTX14 YTX7A????A123??-???
Hello Everyone!
I got my board assembled with 10 LiFePO4 cells last night. Much like MikeyFresh I am having voltage issues on J4. All other ports (J1,2,3&5) are functioning as expected.
When I measure the voltage at J4 it is all over the place, not switching quickly, but different between each power on. Values have been from about 6v to 14v.
Measuring voltages on all the cell directly gives me expected values. I can also measure voltage (with the unit in the ON state) from the negative of BT2 to the positive of BT8 and get approx. 13.2v, as desired.
I checked resistance between the different J ports and the batteries directly, all with the unit in the ON state. Of all the links the only one I get a high resistance value is between the negative of BT2 and the negative of J4. I also measured resistance between the pins of the relays from the bottom of the board, both in the On and OFF state. I believe my problem to be the outer most switch of the K4 relay.
With all that said I have two questions:
1. Does that seem like it could be the problem? What else should I check.
2. Any advice on how to replace this, as all the batteries are installed. Would a solder sucker, hot air, etc... be the best option?
thank you in advance.
I got my board assembled with 10 LiFePO4 cells last night. Much like MikeyFresh I am having voltage issues on J4. All other ports (J1,2,3&5) are functioning as expected.
When I measure the voltage at J4 it is all over the place, not switching quickly, but different between each power on. Values have been from about 6v to 14v.
Measuring voltages on all the cell directly gives me expected values. I can also measure voltage (with the unit in the ON state) from the negative of BT2 to the positive of BT8 and get approx. 13.2v, as desired.
I checked resistance between the different J ports and the batteries directly, all with the unit in the ON state. Of all the links the only one I get a high resistance value is between the negative of BT2 and the negative of J4. I also measured resistance between the pins of the relays from the bottom of the board, both in the On and OFF state. I believe my problem to be the outer most switch of the K4 relay.
With all that said I have two questions:
1. Does that seem like it could be the problem? What else should I check.
2. Any advice on how to replace this, as all the batteries are installed. Would a solder sucker, hot air, etc... be the best option?
thank you in advance.
Because the batteries are connected for higher voltage, not for higher capacity. Read the posts before, so you understand what it is meant for...
Who cares ? Ians PSU is not just 4 connected batteries, it features WAY more and ofcourse all the features this batteries offer... What if you stop spamming this thread with taobao stuff, that nobody wants.
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@yaboin
Sorry about the issue.
First, please check all of the fuse make sure they are good.
Please also check the polarity of each battery cell. If any was reversed, the protection resistors could be damaged.
Connect a load to J4 with around 50mA current, then measure the Voltage on J4.
Also make sure K1 and K2 is on shortly after the first click sound.
Please let me know if you have more update.
Regards,
Ian
Ian,
Thank you for the quick response. No worries on the problem, I shorted the pins with my clips while trimming a battery tab. (they got under the tape...) So most likely I am to blame for the problems.
1. The fuses are both good.
2. All batteries verified to be in the correct orientation.
3. K1 and K2 both appear to be on after power up.
4. I forgot to add a led resistor when applying a load and ended up burning up the LED. The unloaded voltage is not consistent from power up to power up, what would be the best way to apply 50 mA load?
In the image below all the resistors circled in blue measure about 0.1 ohms, while the one in red measures 116k ohms. The relay pins circled in blue behave similarly ( Left two shorted in the On state and right two shorted in the OFF state), the three pins circled in red read 100k+ between the middle and left/right in the ON and OFF state. Also all the resistors labeled 2R0 measure 2 ohms.
Imgur: The magic of the Internet
Thank you for the quick response. No worries on the problem, I shorted the pins with my clips while trimming a battery tab. (they got under the tape...) So most likely I am to blame for the problems.
1. The fuses are both good.
2. All batteries verified to be in the correct orientation.
3. K1 and K2 both appear to be on after power up.
4. I forgot to add a led resistor when applying a load and ended up burning up the LED. The unloaded voltage is not consistent from power up to power up, what would be the best way to apply 50 mA load?
In the image below all the resistors circled in blue measure about 0.1 ohms, while the one in red measures 116k ohms. The relay pins circled in blue behave similarly ( Left two shorted in the On state and right two shorted in the OFF state), the three pins circled in red read 100k+ between the middle and left/right in the ON and OFF state. Also all the resistors labeled 2R0 measure 2 ohms.
Imgur: The magic of the Internet
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