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View Full Version : battery doing weird things, help needed


rondoolaa
15-11-2012, 09:27 PM
i have one of those battery checkers that is just a circuit board with an lcd display wrapped in clear heatshrink,

one of these: http://www.google.co.uk/imgres?q=lipo+checker&hl=en&sa=X&biw=1280&bih=685&tbm=isch&prmd=imvnsfd&tbnid=RhJ8DanCw2pRtM:&imgrefurl=http://tq-tech.en.alibaba.com/product/376337590-210706655/6S_Voltage_Tester_Lipo_Checker_RC_Lipo_Battery_Mon itor.html&docid=Y5rk7Kf6ayxKoM&imgurl=http://i00.i.aliimg.com/photo/v0/376337590/6S_Voltage_Tester_Lipo_Checker_RC_Lipo.jpg&w=526&h=396&ei=x12lUL2EHqia0QWAuoGoCA&zoom=1&iact=hc&vpx=613&vpy=94&dur=6741&hovh=195&hovw=259&tx=139&ty=131&sig=103645025229990785945&page=1&tbnh=122&tbnw=154&start=0&ndsp=20&ved=1t:429,r:7,s:0,i:90

my overlander 2200mah 25c lipo batteries all read ok except 1,

the dodgy one reads on 6 cycles of the voltage readout,

cell 1 = 6.84
cell 2 = d3.2
all = 6.73


cell 1 = 7.00
cell 2 = d3.1
all = 6.75


cell 1 = 7.09
cell 2 = d3.1
all = 6.75


cell 1 = 7.13
cell 2 = d3.1
all = 6.78


cell 1 = 7.16
cell 2 = d3.0
all = 6.79


cell 1 = 7.22
cell 2 = 3.0
all = 6.79


if its just the fact that cell 2 has gone too low then would it be ok to balance charge and would the charger do it ok as one is so low or would i have to lower the higher cell with a bulb or simular, also its weird how after each cycle of the tester the voltage of cell 1 goes up in voltage.....

i have another tester made by fusion but that one reads all my other batteries ok but just does a clicking noise when connected to the battery in question


thanks for any help

imull
15-11-2012, 09:41 PM
Have you got access to a proper DVM/multimeter? I'd check the cells with that first.

Does your charger give you each cell readout? If theres a problem then it probably won't charge the cells anyway.

rondoolaa
15-11-2012, 10:15 PM
Have you got access to a proper DVM/multimeter? I'd check the cells with that first.

Does your charger give you each cell readout? If theres a problem then it probably won't charge the cells anyway.

ive put a multimeter on the balance wires and it shows cell 1 as 3.9v and cell 1 + 2 as 3.9v still, cell 2 on its own doesnt give a read out on the multimeter

CrashBangWallop
16-11-2012, 12:18 AM
Sounds very much like your pack is knackered. First check your charger is working ok by balance charging another pack on it.
Check your speedo if running brushless that the Li-po cut off voltage is set to 3v per cell.

rondoolaa
16-11-2012, 05:16 PM
it is weird, when i put the multimeter on it one cell is reading nothing and one 3.8 but when i connect to checker i get over 7 volt, very unusual, think i'm just gunna bin it, shame as no swelling and never been over worked


all my chargers work fine, 1 x ansman xbase deluxe and 2 x orion advantage touch and my speedo are all set on around 3.2v per cell cut off,

the batterys havnt been used for about 2 months, but 5 are still the same voltage i left them at and its just the one thats gone bad.

stegger
16-11-2012, 09:10 PM
If you arn't getting a reading at all on cell 2 with a multi meter then it must be a poor connection !