New charger

[FP Dave]

Got a new charger today, imax b4ac. I thought I try it out so I flatten a battery (1s 3.7v) and put it on. It's now be on for 48 minutes and still charging. But how will I know when it's finished? It's showing 3.9v and a charged capacity of 77. On the charger that came with the heli only took about 20-30mins. Any help would be gratefully received.

[Nick_C]

Hi,what mah is battery,and what rate are you charging at

[Nick_C]

I usually charge my 1s 150mah batteries at 0.3 amp,which is 2c rate

[FP Dave]

Hi,what mah is battery,and what rate are you charging at

The battery is a 160mah and I've got it on 0.1a. I'm not understanding the setting yet, and that is what it started up with.

[Nick_C]

The battery is a 160mah and I've got it on 0.1a. I'm not understanding the setting yet, and that is what it started up with.

Thats why taking so long to charge,increase to 0.3 amp and try it

[FP Dave]

Thats why taking so long to charge,increase to 0.3 amp and try it

Cheers Nick.
Just trying to get my head round it. Am I right in thinking if I have one battery it should be 0.2-0.3a, but if I put 3 batteries on it should be more like 0.5-0.6?
It will switch off when charged?

[Nick_C]

Cheers Nick.
Just trying to get my head round it. Am I right in thinking if I have one battery it should be 0.2-0.3a, but if I put 3 batteries on it should be more like 0.5-0.6?
It will switch off when charged?

Yes,times the battery capacity by the amount of batteries being charged,3 x 150 =4.5a at 1c rate,and chrger will turn it self off when done

[FP Dave]

Thanks again Nick, I appreciate your help.
The battery finished in about 5 minutes when I turned it up.

[Nick_C]

No probs,thats great

[Planehazza]

Also, when you say flatten, how low did you take the LiPo? The recommended safe charge rate of LiPos is 1C, though many can be charged at 2C or more these days. 0.16A is 1C for a 160mAh pack

[FP Dave]

Also, when you say flatten, how low did you take the LiPo? The recommended safe charge rate of LiPos is 1C, though many can be charged at 2C or more these days. 0.16A is 1C for a 160mAh pack

I only flatten it with a 4 minute flight. Sorry but what is 1c and 2c?

[DrSteve]

Good guide here to C rating:



The variable C and how it applies - TJinTech

[FP Dave]

Good guide here to C rating:



The variable C and how it applies - TJinTech

Thanks Steve.
I understand now, and learnt a lot more from that site too!

[choppaholic]

Yes,times the battery capacity by the amount of batteries being charged,3 x 150 =4.5a at 1c rate,and chrger will turn it self off when done

Just a note 3x150mah =0.45a not 4.5a I am sure its a typo, but if you did try it , you surely set the batt on fire so just a caution on 150 mah batts I would not exceed 2 to 3 c the batt is to small to take high amps

[Nick_C]

Just a note 3x150mah =0.45a not 4.5a I am sure its a typo, but if you did try it , you surely set the batt on fire so just a caution on 150 mah batts I would not exceed 2 to 3 c the batt is to small to take high amps

Sorry,my mistake,meant to put 0.45 amp! That would kill batts at 4.5a