my Battery is weird? please help

[MRCCRAWLER1.9]

alright, so i have the blue cell lipos from hobbypartz in my losi mini rock crawler, and its soon going to be passed onto my xr-10..

only issue right now is that when its around 3.6V per cell there isnt any more power and its not even close to lipo cut off..

i dropped it into my slash 2wd, and it properly goes down all the way to 3.2V which is the cut-off i want.

im using the castle micro mamba in the MRC if that helps..

[TattooKenny]

What is the cut off set at on your ESC? Have you plugged the Castle Link into it to check?

[MRCCRAWLER1.9]

my cut off right now is at 6.4V, 3.2V per cell..

ive checked over and over. still the same cut-off, but the lipo itself slows down at around 3.6v.

[Charlie-III]

Is this a 2S or 3S pack?
If so, try running the battery down again, when the rig stops, quickly check it's voltage.
You "may" have a cell that is going flat which pulls the pack below the LVC (low voltage cutoff) but with no load on it, it may pop back up to seem normal.

In general, a failing cell can "look normal" just sitting there, but the discharge curve can drop off quickly under load.

[MRCCRAWLER1.9]

Originally Posted by Charlie-III

Is this a 2S or 3S pack?
If so, try running the battery down again, when the rig stops, quickly check it's voltage.
You "may" have a cell that is going flat which pulls the pack below the LVC (low voltage cutoff) but with no load on it, it may pop back up to seem normal.

In general, a failing cell can "look normal" just sitting there, but the discharge curve can drop off quickly under load.

its a 2s lipo.


the issue is that it doesnt hit LVC at All. what happens is the performance drops like a NIMH, where the power gradually slows down, and doesnt make it to LVC.

[Charlie-III]

Originally Posted by MRCCRAWLER1.9

its a 2s lipo.


the issue is that it doesnt hit LVC at All. what happens is the performance drops like a NIMH, where the power gradually slows down, and doesnt make it to LVC.

I understand, but, you still have an issue.
How/when do you check battery voltage? It still sounds like you have a failing cell that hits LVC (for the pack) but bounces back up if you take too long to check voltage.
Maybe check cell voltage off the balancing plug.
I have also used a "meter" that plugs into the balancing plug of the pack and it scans each cell as well as total voltage.

[MRCCRAWLER1.9]

Originally Posted by Charlie-III

It still sounds like you have a failing cell that hits LVC (for the pack) but bounces back up if you take too long to check voltage.
Maybe check cell voltage off the balancing plug.
I have also used a "meter" that plugs into the balancing plug of the pack and it scans each cell as well as total voltage.

i think that sounds just about right. ill run my kit today, and pull out a multimeter and check the balance cable.. see if 1 cell does fall below LVC before the other..

[DickyT]

Originally Posted by MRCCRAWLER1.9

i think that sounds just about right. ill run my kit today, and pull out a multimeter and check the balance cable.. see if 1 cell does fall below LVC before the other..

Be sure to test it with load on it. Sitting idle voltages bounce back up some.

[MRCCRAWLER1.9]

i dont think i have time to run it in my crawler.. but in running the bat on my touring car, to get it back and running.. see what happens.. but you guys are right.. one of the cells is loosing voltage faster than the other.. right now ive been running full throttle for 5-10min.. the voltage is already at 3.57v and 3.48v

[MRCCRAWLER1.9]

hmm same performance through the whole time, and went into LVC perfectly..


weird..