Lipo going down to 2.95v, does it safe when in under load?
05-20-2013, 03:22 AM
#1
Lipo going down to 2.95v, does it safe when in under load?
guys... wanna ask something.....
i was played drift a while ago and i thought lvc in my esc will kick in.
accidentally i overdischarge the lipo cell number 2 to 2.95v when i used it, but after i quickly turn it off, it will stable at 3.06v immidiately
the question is, will it damage the lipo? especially when the battery under load to 2.95v?
need someone who have a real experience about this.... thx
i was played drift a while ago and i thought lvc in my esc will kick in.
accidentally i overdischarge the lipo cell number 2 to 2.95v when i used it, but after i quickly turn it off, it will stable at 3.06v immidiately
the question is, will it damage the lipo? especially when the battery under load to 2.95v?
need someone who have a real experience about this.... thx
05-20-2013, 04:47 AM
#2
anyone?
05-20-2013, 10:05 AM
#3
Not if u just did It one time, but iff u keep running it pas the lv it will damage the lipo, fast!!
05-20-2013, 07:25 PM
#5
yesterday it still worked?
05-20-2013, 07:58 PM
#6
Battery voltage drops according to load (amp draw), which occurs in spikes, so most batteries will often see voltages lower than the recommended cutoff point, also in spikes. The thing to do is to avoid over-exposure to those low voltages, which requires to have a higher LVC than the minimum, like previously mentioned. Exactly how high depends on the person. Personally, the stronger the system I run, the higher I set the LVC. Ex: I like to set it ~3.6 for 1/8 scale, and ~3.4 for 1/10.
The only way I know of to determine battery degradation is to measure the internal resistance during load, which is something the average ESC won't do, along with doing a capacity test on a charger. (I'm assuming when you said "they" you meant the ESC, as when it goes into sleep mode?)
The only way I know of to determine battery degradation is to measure the internal resistance during load, which is something the average ESC won't do, along with doing a capacity test on a charger. (I'm assuming when you said "they" you meant the ESC, as when it goes into sleep mode?)
05-20-2013, 08:08 PM
#7
Battery voltage drops according to load (amp draw), which occurs in spikes, so most batteries will often see voltages lower than the recommended cutoff point, also in spikes. The thing to do is to avoid over-exposure to those low voltages, which requires to have a higher LVC than the minimum, like previously mentioned. Exactly how high depends on the person. Personally, the stronger the system I run, the higher I set the LVC. Ex: I like to set it ~3.6 for 1/8 scale, and ~3.4 for 1/10.
The only way I know of to determine battery degradation is to measure the internal resistance during load, which is something the average ESC won't do, along with doing a capacity test on a charger. (I'm assuming when you said "they" you meant the ESC, as when it goes into sleep mode?)
The only way I know of to determine battery degradation is to measure the internal resistance during load, which is something the average ESC won't do, along with doing a capacity test on a charger. (I'm assuming when you said "they" you meant the ESC, as when it goes into sleep mode?)
05-20-2013, 10:58 PM
#8
Can you share some of the references that mention 2.7V? (Is it for lipo, not another lithium chemistry, and/or current info?)
I’m not sure on the damage. One issue is the LVC doesn't detect individual cells, only an overall pack voltage. It’s possible for one cell to be far lower than the others if the pack is getting out of balance. I know I stay above 3.2V under load, rarely below 3.6-3.7V after returning to rest, and that seems to work really well for me. I track internal resistance and occasionally voltage under load to confirm.
One of the reasons I don’t go lower is the performance drops off so much the car is noticeably slower. I rarely hit LVC because of the performance decrease. Here is a typical set of discharge curves, even at a 50C constant discharge there isn’t much left after 3.4-3.2V under load.
I’m not sure on the damage. One issue is the LVC doesn't detect individual cells, only an overall pack voltage. It’s possible for one cell to be far lower than the others if the pack is getting out of balance. I know I stay above 3.2V under load, rarely below 3.6-3.7V after returning to rest, and that seems to work really well for me. I track internal resistance and occasionally voltage under load to confirm.
One of the reasons I don’t go lower is the performance drops off so much the car is noticeably slower. I rarely hit LVC because of the performance decrease. Here is a typical set of discharge curves, even at a 50C constant discharge there isn’t much left after 3.4-3.2V under load.
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