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View Full Version : 1000mAh fujicell break-in help


cdog4w
2007.03.21, 04:04 PM
I started breaking in my first set of 4 cells, but I'm wondering if I chose the best path. I have 5 more sets to break in so any suggestions would be great. All charging was done on a triton in a 4 cell AAA pack with a fan on all batteries. I listed the settings for each cycle and how much was discharged and then charged. Voltage off the 4 cells fresh out of the shrinkwrap was right on 5V. All cycles started with discharge followed by a charge with 5 minutes in between.

cycle 1: 0.2A dis / 0.2A chrg 5mV deltaV 1.0V cutoff
263mAh / 424mAh
cycle 2: 433mAh / 558mAh
cycle 3: 0.5A dis / 0.5A chrg 5mV deltaV 0.8V cutoff
583mAh / 611mAh

Seems like I should be getting more capacity out of the cells, but perhaps it just needs more cycles?

Thanks in advance!

Sinister_Y
2007.03.21, 05:36 PM
Hi,

I'm no electronic wiz, but since you're working with 4 cells in series...you should be using 4x what the settings were that you're using.

On a big note, your cutoff is way too low for 4 cells in series, i.e. 1.0V, it should be 4.0V...you may have damaged your cells.

According to the fujicell spec sheet, slow rate charge is around 0.2 A like you stated, except for each cell, not 4, i.e. also 4 V cutoff, i.e. also charging, etc...

cdog4w
2007.03.21, 06:26 PM
Hi,

I'm no electronic wiz, but since you're working with 4 cells in series...you should be using 4x what the settings were that you're using.

On a big note, your cutoff is way too low for 4 cells in series, i.e. 1.0V, it should be 4.0V...you may have damaged your cells.

According to the fujicell spec sheet, slow rate charge is around 0.2 A like you stated, except for each cell, not 4, i.e. also 4 V cutoff, i.e. also charging, etc...

Triton was set for 4 cells so those were per cell settings. Sorry, should have stated that.

kartermdb
2007.03.21, 08:48 PM
those are the batteries i prefer, they are awesome batteries, they hold up awesome, mine are a year old and are still charging over 850 mah. what charger are you using? i charge them at 1.4 amps with a .7 mv cutoff on my duratrax ice, and i peak them at 2 amps, and they kick really hard for our 5 min races here.

cdog4w
2007.03.22, 01:23 AM
those are the batteries i prefer, they are awesome batteries, they hold up awesome, mine are a year old and are still charging over 850 mah. what charger are you using? i charge them at 1.4 amps with a .7 mv cutoff on my duratrax ice, and i peak them at 2 amps, and they kick really hard for our 5 min races here.

How hot do they get at 1.4A charge? I really need to pick up a temp probe for the triton...

I just ran the 4th cycle 1.5A discharge followed by 0.9A charge, 7mV peak and 0.9V cutoff on the discharge. I also set the total mAh cutoff to 1000mAh which I ended up hitting on the charge :) In the end, it dicharged 604mAh from the previous charge and charged 1000mAh, so I think I'm good now.

Trying a fresh set with 2 cycles at 0.2A discharge, 0.9V cutoff, then 0.2A charge with a 6mV deltaV peak detection. Will post results.

UPDATE:
cycle 4: 1.5A dis / 0.9A chrg 7mV deltaV 0.9V cutoff (1000mAh max capacity)
604mAh / 1000mAh

I think the 7mV deltaV peak detection was a bit too high since it hit the 1000mAh cutoff before stopping, not the peak detection. That or it could have kept charging safely, who knows.

kartermdb
2007.04.05, 08:53 PM
oh they get warm, similar to my sub c 6 cells i use for touring mod, peaking about 130 to 140 degrees, hot enough to make you roll them in your hand as you go to put them in lol but im not really worried i get fugi cells for cheap so if they stop charging, ill just get more :D

dont worry about charging them over 1000 mah, let them go til they peak voltage wise, that way you know they are fully charged