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Charging with benchtop in series

sonny93

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hi all!

last night I successfully used my lifepo4 battery pack for 3 hours while busking in the street. I powered a valve amp and several guitar pedals (even scored 10 bucks ! )

i want to charge the batteries up as they were at 60% soc on the app. There isnt much information on charging in series with just a benchtop and I dont want to damage the bms or batteries after finally coming this far.

As per photos, ive connected the + and - of the benchtop to the corresponding terminals of the cells. The bms is attached also.
Am I okay to turn the benchtop power supply and charge to 14.6V? Do I set the current to max on the benchtop or would this damage the bms?
 

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Got impatient so I switched it on and set the volt and currents to max on the power supply
 

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Last edited:
set bench top to 13.8 v amps max. disconnect bench top first before setting voltage do not touch voltage nob again

ps your wooden box is wrong
1 your cells are not on compression now
2 no isolation between the cells
 

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If you charge via the bms, as you corrected in the second picture, the bms should protect the cells if you exceed cell volts. Use any voltae setting up to 14.6, if the cells are inbalanced reduce the volts, 13.8 to 12v will still charge.
Disagree with the box, it seems to have a significant restraining action against cell expansion.
Isolation material between cells is an optional extra, not needed if the blue covering is undamaged.

At all times the battery needs the bms in circuit. Always regard the P- as the battery 'negative'.

Adding a suitable fuse to the feed from the battery positive would be a useful safeto feature. Using the battery box in a mobile situation would benefit from a lid to prevent accidental short of the cells.

Mike
 
If you charge via the bms, as you corrected in the second picture, the bms should protect the cells if you exceed cell volts. Use any voltae setting up to 14.6, if the cells are inbalanced reduce the volts, 13.8 to 12v will still charge.
Disagree with the box, it seems to have a significant restraining action against cell expansion.
Isolation material between cells is an optional extra, not needed if the blue covering is undamaged.

At all times the battery needs the bms in circuit. Always regard the P- as the battery 'negative'.

Adding a suitable fuse to the feed from the battery positive would be a useful safeto feature. Using the battery box in a mobile situation would benefit from a lid to prevent accidental short of the cells.

Mike
Thanks Mike!
I have a 50A inline fuse normally attached to the positive of the battery. Are you suggesting I keep this attached while also charging with the psu just in case?

fortunately the output of the psu cant exceed 10A
 
Gosh this stuff can get fiddly and frustrating...
Why is my psu jumping between pushing current to not pushing current? Only displaying voltage and clamp meter reads no current being pushed. I have the current knob set to max

see photos for where the psu jumps between. Right now it is just staying at 14.26V and no current whats this mean? I have no idea how these psus are working
 

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Gosh this stuff can get fiddly and frustrating...
Why is my psu jumping between pushing current to not pushing current? Only displaying voltage and clamp meter reads no current being pushed. I have the current knob set to max

see photos for where the psu jumps between. Right now it is just staying at 14.26V and no current whats this mean? I have no idea how these psus are working
i think your charge mos is switching on and off. cell protection set to 3.4v? probably your psu is set to 14.26 v
by the way if you charge to 13.8 v your battery will be 99% full no need to charge it higher
 
i think your charge mos is switching on and off. cell protection set to 3.4v? probably your psu is set to 14.26 v
by the way if you charge to 13.8 v your battery will be 99% full no need to charge it higher
The only setting that I have that reads 3.4V is the balanced open start volt. Photos attached. Any clues? I think I have seen the charge MOS thrning on and off in the app
 

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The only setting that I have that reads 3.4V is the balanced open start volt. Photos attached. Any clues? I think I have seen the charge MOS thrning on and off in the app
Yep chg MOS light in app going green and grey
 
can you hook it up to a computer and send me a log file when you are charging, also a back up of your configuration.

 
hi all!

last night I successfully used my lifepo4 battery pack for 3 hours while busking in the street. I powered a valve amp and several guitar pedals (even scored 10 bucks ! )

i want to charge the batteries up as they were at 60% soc on the app. There isnt much information on charging in series with just a benchtop and I dont want to damage the bms or batteries after finally coming this far.

As per photos, ive connected the + and - of the benchtop to the corresponding terminals of the cells. The bms is attached also.
Am I okay to turn the benchtop power supply and charge to 14.6V? Do I set the current to max on the benchtop or would this damage the bms?
You have it connected so as to bypass the BMS, that is not a good idea.
Use the BMS, that's what it is for.
 
You have it connected so as to bypass the BMS, that is not a good idea.
Use the BMS, that's what it is for.
I fixed this
i already fixed this as per the other posts after I realised it myself.

the problem is still persisting after changing the psu to 5 amps instead. It jumps between 13.7V and 4.95 amps TO 14.49 and 0 ampsUnsure what to do. Any other suggestions? Photos attached for values, changes every 5 seconds
 

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The chg MOS button in the app goes from green to grey each time it changes too so the BMS is doing something. Could someone please decipher the settings I posted earlier to work out what I have incorrectly calibrated?
 
I fixed this

i already fixed this as per the other posts after I realised it myself.

the problem is still persisting after changing the psu to 5 amps instead. It jumps between 13.7V and 4.95 amps TO 14.49 and 0 ampsUnsure what to do. Any other suggestions? Photos attached for values, changes every 5 seconds
Go the full distance and replace the banana jacks. 1/4 ring terminals should fit fine.
 
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