LiFePo4 remove compression when charged

tweekzilla

New Member
Joined
Jun 23, 2021
Messages
33
So I built my nice 16s 280aH LiFePo4 pack and top balanced it. Unfortunately I top balanced it in a location that is nowhere near the invertor. I now need to either

  1. lug a 200lb pack into a very awkward space
  2. Discharge a 13kWh pack at 3.3V - read very long time
  3. Dismantle the pack and remove the compression whilst charged then reassemble in final location
I've seen a couple of videos that clam item 3. is a very bad idea and the cells will swell permanently if I did this. I've also seen vidoes where people top balance without any compression at all. So the questions is. Can I dismantle the pack - move it and reassemble it fully charged. Note these are new cells and looked great upon delivery.
 

DThames

Photon Sorcerer
Joined
Nov 22, 2019
Messages
1,428
Is your compression like a spring or more like, rigid? If rigid, then the main tension would be from the cells wanting to swell. If you can back the pressure off a bit, like loosen screws a little, you might be able to slide a piece of paper between cells, showing you there is not pressure from the high state of charge. But if you have spring type compression, this might not be as simple.
 

tweekzilla

New Member
Joined
Jun 23, 2021
Messages
33
Is your compression like a spring or more like, rigid? If rigid, then the main tension would be from the cells wanting to swell. If you can back the pressure off a bit, like loosen screws a little, you might be able to slide a piece of paper between cells, showing you there is not pressure from the high state of charge. But if you have spring type compression, this might not be as simple.
Yeah it's just a threaded rod - If it's not permanent then I don't think it's a big deal. I could maybe move them but not compress initially, do a discharge via the inverter one time and then compress again whilst in a low state. It's just that "woah don't do that they will permanently deform" which has got me worried a bit.
 

DThames

Photon Sorcerer
Joined
Nov 22, 2019
Messages
1,428
Tie a piece of wire around the pack, loosen up the nuts and see if the wire gets tighter. If it does, you know they are wanting to expand.
 

DLTooley

Solar Enthusiast
Joined
Jan 12, 2020
Messages
131
Can you reconfigure your bus bars and discharge at a higher voltage? If needed.
 
Top