coolgabsi
Super Mod & DEAL KING!
Had put 2 12s packs to balance charge . Was in sight but I couldn't see details and was rebuilding the warp. Well watched a full movie and still the packs didn't say completed charging. Still balancing. I go over and all packs are cool nothing wrong.
Well I start inspecting things. And one pack, outer shell is hard is it is supposed to be, but one of the 6 cells looks a bit deformed.. Wierd. Pull all batteries from charge and start checking internal resistances. This one 6s in the 12s duo, gives 140 mOhm and doesn't wanna give any cell wise reading.
I inpecr it further and it seems like there is moisture on the inside of these packs. Inside like two layers of clear heat sshrink in. Wierd..
Then turn the pack around for closer look, one cell right in the middle has lost it's seal.. Opened , I can see black on the inside.. And hold the battery eye level, I can see there is a little deformation in the outer shape!! Wow!
If I hadn't noticed this would have turned into a fire!
Why this happened? Cells were not on storage charge for over two months sitting in a cool place with no checking.... I preach it but I didn't follow.
Please make sure your cells are on storage charge (3.8v/cell) on storage for long times and monitor them every once in a while! Please balance charge big capacity packs when possible.. And check IR often
Good packs iR --- 1---5mOhm
Weak pack ---6---12mOhm
Higher... Is low low power and after 20.. Heli probably won't lift off easy
Please be safe
Will post a pic of the pack which is now sitting out on te concrete patio
Well I start inspecting things. And one pack, outer shell is hard is it is supposed to be, but one of the 6 cells looks a bit deformed.. Wierd. Pull all batteries from charge and start checking internal resistances. This one 6s in the 12s duo, gives 140 mOhm and doesn't wanna give any cell wise reading.
I inpecr it further and it seems like there is moisture on the inside of these packs. Inside like two layers of clear heat sshrink in. Wierd..
Then turn the pack around for closer look, one cell right in the middle has lost it's seal.. Opened , I can see black on the inside.. And hold the battery eye level, I can see there is a little deformation in the outer shape!! Wow!
If I hadn't noticed this would have turned into a fire!
Why this happened? Cells were not on storage charge for over two months sitting in a cool place with no checking.... I preach it but I didn't follow.
Please make sure your cells are on storage charge (3.8v/cell) on storage for long times and monitor them every once in a while! Please balance charge big capacity packs when possible.. And check IR often
Good packs iR --- 1---5mOhm
Weak pack ---6---12mOhm
Higher... Is low low power and after 20.. Heli probably won't lift off easy
Please be safe
Will post a pic of the pack which is now sitting out on te concrete patio