I tried to rotate the batteries and now seems to work correctly (I'm listening since 3 hours without problems).
I suspect to have one battery not perfect. Now probably is in the row in series to obtain 13V for I/V board.
@paoloilpizza,
Hmmm... Are they new cells from a reputable seller or ones that could be used or rejects from someone we may not want to trust?
@ilgavro,
Thanks for the details. JUST to keep the battery rails both totally isolated AND not introduce unneeded load (and also possibly noise) into one of the battery rails, IF IT WERE ME, I'd either:
- Take the relay energizing voltage from the 5V non-isolated supply. IF 5V is too high for the relay coils, then use a small dropping resistor.
or
- Take the relay energizing signal from any of the existing relay coils and use a small transistor relay driver circuit (search for them, sorry, I don't have one handy nor am I an EE, so I can't conjure one from thin air) powered from the input voltage into the board. Depending one the nominal coil voltage of the relays used and the parts in the driver circuit, you MAY need to drop the input voltage with a small regulator.
Yah, I know either a more complex, but like my sig says, 'Everything Matters'.
Of course, whether one can hear it is a different matter!
Greg in Mississippi
Hmmm... Are they new cells from a reputable seller or ones that could be used or rejects from someone we may not want to trust?
@ilgavro,
Thanks for the details. JUST to keep the battery rails both totally isolated AND not introduce unneeded load (and also possibly noise) into one of the battery rails, IF IT WERE ME, I'd either:
- Take the relay energizing voltage from the 5V non-isolated supply. IF 5V is too high for the relay coils, then use a small dropping resistor.
or
- Take the relay energizing signal from any of the existing relay coils and use a small transistor relay driver circuit (search for them, sorry, I don't have one handy nor am I an EE, so I can't conjure one from thin air) powered from the input voltage into the board. Depending one the nominal coil voltage of the relays used and the parts in the driver circuit, you MAY need to drop the input voltage with a small regulator.
Yah, I know either a more complex, but like my sig says, 'Everything Matters'.
Of course, whether one can hear it is a different matter!
Greg in Mississippi
Hi Greg
The cell are new bought in a German site (A123 ANR26650M1-B LiFePO4 Akkuzellen | i-tecc LiFeEnergy)
Honestly I didn't understand what happened.
Now the board works fine.
I tested the voltage of the batteries before to start using them, during the usage and when the board start to recharge but the voltage of all batteries are (more or less) the same and the right voltage.
I did two things:
I rotated the batteries
I changed the default time out setting 6hr (instead of 5hr)
I would try to restore the old position of the batteries to verify what happens.
G2RL-2-5DC Relay electromagnetic DPDT Ucoil5VDC 8A/250VAC 8A/24VDC G2RL-25VDC https://www.amazon.it/dp/B01M4IPN6K/ref=cm_sw_r_cp_apa_i_pov9CbJTH5PNC
Could it resolve the problem ?
I've come across an issue with one of my three LiFePO4 boards. In troubleshooting I found that in "Off" mode the (-) of all the batteries are connected (grounded for charging). I'm not sure if the (+) terminals are connected or independent. In any case it seems theoretically possible one could have a 3.3V always on (but would not be floating in charge mode). However, any series connections would be a Chernobyl (I'm watching the HBO series) in charge mode as it would be a dead short.
I believe I have a bad relay connected to BT4.
In off mode, measuring underside of PCB, all batteries measure +3.3V
In On mode:
(-)BT2 to (+)BT6 = +13.2V
(-)BT3 to (+)BT1 = +6.6V
(-)BT4 to ANY (+) = 0V (I don't understand this. shouldn't I get +3.3V to BT4?)
(-)BT5 to (+)BT5 = +3.3V
(-)BT5 to (+) of BT4 or BT3 or BT1 = 0V
In off mode, measuring underside of PCB, all batteries measure +3.3V
In On mode:
(-)BT2 to (+)BT6 = +13.2V
(-)BT3 to (+)BT1 = +6.6V
(-)BT4 to ANY (+) = 0V (I don't understand this. shouldn't I get +3.3V to BT4?)
(-)BT5 to (+)BT5 = +3.3V
(-)BT5 to (+) of BT4 or BT3 or BT1 = 0V
I had a similar situation before. One 13.2V rail measured low at ~10V. When I check individual cells during pending mode one cell measured 0 volt. The charging cycle appeared to work as expected though. I removed that cell and it did measure 0V so I replaced it with another one which fixed the problem.
One thing to note: the two rows of cells for the two higher voltage rails are LEFT/RIGHT swapped compared to the output terminal blocks (I have Mk.1 battery board). I.e., the left terminal block is in fact connected to the right row of battery and vice versa.
One thing to note: the two rows of cells for the two higher voltage rails are LEFT/RIGHT swapped compared to the output terminal blocks (I have Mk.1 battery board). I.e., the left terminal block is in fact connected to the right row of battery and vice versa.
I had checked each battery prior to installation. You had a low output indicating a bad battery, but I get 0V/no output at the suspect terminal block (the other 3 being okay). When I get home I will take the each battery out and check again though.
I have been using Ian's LiFePO4 unit successfully for some time (with FifoPI 9038Q2MPi I/VSTD). During the weekend I stacked my other LiFePO4 unit to provide 2 additional rails for the Ian's DAC. The added unit has just two cells (BT6 & BT7). It works well, but during charging and pending it makes quite an awful whistling sound (high pitched buzz).
I have used different 12V AC-DC adapters, either connected separately or just one powerful one.
Any hints what to check first?
I have used different 12V AC-DC adapters, either connected separately or just one powerful one.
Any hints what to check first?
@nielsek,
Can you try a laptop adapter around 18.5V capable for 4A or higher?
The charging current can go up to 10A. I think your current adapter doesn't have enough power for more battery cells.
Ian
I tried 2 different 12V ones, both were around 4A, guite big ones.
I have 20V ones but nothing in between. Could test with 30V/3A lab supply, setting the voltage limit to 19V.
Kent
I did some tests, separating the stack and powering just the whistling unit with different 12V power bricks. The result is same.
Then I tried different batteries and also without any, which also produced the whistling while connected to power bank. Unfortunately, putting back the batteries I was able to reverse terminals on BT7 and create some smoke. Looking at the back, seems that one of the R015 resistors is burnt. Image attached.
The unit can still turn on and provide voltage. I have not yet connected it to DAC though, just to be sure.
Please advise, how to proceed.
Then I tried different batteries and also without any, which also produced the whistling while connected to power bank. Unfortunately, putting back the batteries I was able to reverse terminals on BT7 and create some smoke. Looking at the back, seems that one of the R015 resistors is burnt. Image attached.
The unit can still turn on and provide voltage. I have not yet connected it to DAC though, just to be sure.
Please advise, how to proceed.
Attachments
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@nielsek,
That the unit still turns on suggests you might be good by just replacing that resistor. Go back over the posts in this thread for the last 2-3 weeks to find the PN.
The output power SHOULD still be ok, though I suggest measuring it. When the unit is turned on, the relays connect the cells to the output... when off, to the charging circuitry. So the on-state is likely not affected. BUT AFAIK, it won't charge that cell correctly.
Sounds like you haven't yet tried the lab supply with the output voltage limited to 19V. Please try that and let us know if the whistling still occurs. Sorry, I have not powered mine with 12V supplies... I'll look around and see what 12V supplies I have that would be appropriate and give it a try.
Finally, if you have not yet color-coded your cells for polarity, please do so. That has helped me NOT connect them in reverse-polarity.
Greg in Mississippi
That the unit still turns on suggests you might be good by just replacing that resistor. Go back over the posts in this thread for the last 2-3 weeks to find the PN.
The output power SHOULD still be ok, though I suggest measuring it. When the unit is turned on, the relays connect the cells to the output... when off, to the charging circuitry. So the on-state is likely not affected. BUT AFAIK, it won't charge that cell correctly.
Sounds like you haven't yet tried the lab supply with the output voltage limited to 19V. Please try that and let us know if the whistling still occurs. Sorry, I have not powered mine with 12V supplies... I'll look around and see what 12V supplies I have that would be appropriate and give it a try.
Finally, if you have not yet color-coded your cells for polarity, please do so. That has helped me NOT connect them in reverse-polarity.
Greg in Mississippi
Thanks Greg. I did look for .015R resistor PN but couldn't find it. Did order these ones WW20NR015FTL WALSIN - Resistor: power metal | TME - Electronic components, 2010 casing.
As I'm not using the 3.3V-13.2V rails, could I just swap one .015R resistor from there, until I have sourced for new one?
Concerning testing different power supplies (12V > 19V), the other LiFePO4 unit fully loaded with 10 batteries works correctly with all my 12V supplies. Of course I will proceed with testing different AC-DC adapters. I just don't think the whistling noise is caused by that.
The lab supply I have, probably didn't have enough power. I did test it with full stack (2 LiFePO4 units and 12 batteries).
Thanks for the help, hopefully I'm able to replace the resistor and test more.
Hi Deenoo ,
How about those resistors marked 2R0 ? Are they current sense resistors also ?
Can you help to show the part number ?
How about those resistors marked 2R0 ? Are they current sense resistors also ?
Can you help to show the part number ?
@Deenoo, THANKS on the .015R PN! You were faster than me.
The PN for the ones marked 2R0 is:
Digi-Key Part Number 541-2.00ACCT-ND 541-2.00ACCT-ND
Manufacturer Vishay Dale
Manufacturer Part Number CRCW20102R00FKEF CRCW20102R00FKEF
Description RES SMD 2 OHM 1% 3/4W 2010
Greg in Mississippi
P.S. @nielsek, I just noticed in your picture you added the jumpers on the cell positions closest to the cells you have in place for the 3.3V-13.2V, but not for any of the other positions. You have to have a jumper in every position where there is not a cell. At least that is what I found when I traced the cell circuit and what worked on my setup.
When I finally get around to updating the manual, I will make that clearer.
Greg
The PN for the ones marked 2R0 is:
Digi-Key Part Number 541-2.00ACCT-ND 541-2.00ACCT-ND
Manufacturer Vishay Dale
Manufacturer Part Number CRCW20102R00FKEF CRCW20102R00FKEF
Description RES SMD 2 OHM 1% 3/4W 2010
Greg in Mississippi
P.S. @nielsek, I just noticed in your picture you added the jumpers on the cell positions closest to the cells you have in place for the 3.3V-13.2V, but not for any of the other positions. You have to have a jumper in every position where there is not a cell. At least that is what I found when I traced the cell circuit and what worked on my setup.
When I finally get around to updating the manual, I will make that clearer.
Greg
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Thanks, ordered some.
First I thought I need 3 additional rails for the DAC, but 2 was enough, so I just used BT6/7.
I used my lab supply with 19V and no more whistle! It's only there when using 12V bricks. I didn't have much time today to use more voltages but will try that in near future.
I checked the burnt R015 sense resistor and it's still working. Just to be sure, switched it with a fresh one from a rail I'm not using.
The strange thing is that for 5 seconds the Lifepo4 unit is charging and then 5 seconds pending and so on. Both when using 19V or 12V brick. When using the latter, the whistling sound is changing a bit, from pending to charging.
I checked all the resistors on the back with multimeter, they were all OK.
Also connected the 2 rails to DAC and everyting is OK, of course I won't risk it with charging as it keeps changing from pending to charging every 5 seconds.
Unfortunately I can't be 100% sure if this was present before I reversed the battery. I used this Lifepo4 unit just for few days and it was stacked under the other one, so didn't see the OLED correctly.
What should I test next? Batteries are running empty while listening good quality audio, need to get them charged
