RC Groups

RC Groups
    Batteries and Chargers
        Discussion Help, Lipo Battery wont seem to charge up all the way

#1 j3noob Jan 19, 2013 09:42 PM

Help, Lipo Battery wont seem to charge up all the way
 
Hi, I have only had 4 flights on my new 11.1v 1100Mah lipo, and Ive had it on the charger for 2 hrs and it is only going up to around 10.75. It is a cheap FMS balance charger but it went up to full charge in an hour before. Also, It only ran down to about 10 on my last flight before losing so much power that it wouldnt take off. I am new to lipos so any input would be greatly appreciated. Thanks!

#2 Wintr Jan 19, 2013 11:33 PM

Sounds to me like you over-discharged the battery. While loaded, 10V may be OK, depending on how much current the load represents, but if that was the voltage after is was unplugged a while, then it was too low. Have you measured the voltage of each cell? I suspect you'll find one is lower than the rest.

#3 bossee Jan 20, 2013 03:02 AM

Hi,

If one or more cell goes "bad" an indication of that is that it takes long time to get the battery pack fully (balanced) charged. The bad cell(s) will strugle to reach 4.20 volt (=fully charged). I have experienced this myself. I would guess that most common cause for this (exept the battery had many cycles on it) is that a battery has been run down to almost empty. Always leave about 20% of capacity in the battery when flying, the absolute minimum 10%. Otherwise the LiPo pack may get a shorter life then it otherwise will have. Another good thing is to storage charge the Lipo to 50-60% if capacity when You do not intend to use the battery for maybe a week (to have them fully charged ready for useage will be OK for a day or two).
Although balance charging is prefered You do not need to do that every time at the field (if You charge at the field). It goes faster to charge. You can set in many charger that it will end charging when it is charged to for example 95% - the last 5% usually takes long since then the balancing is working most at the end of charging process. But balance charge as often as it is practical possible to get all cells fully charged to 4.20 volt.

/Bo

#4 ggcrandall1 Jan 20, 2013 05:54 AM

Quote:

Originally Posted by j3noob (Post 23867065)
Hi, I have only had 4 flights on my new 11.1v 1100Mah lipo, and Ive had it on the charger for 2 hrs and it is only going up to around 10.75. It is a cheap FMS balance charger but it went up to full charge in an hour before. Also, It only ran down to about 10 on my last flight before losing so much power that it wouldnt take off. I am new to lipos so any input would be greatly appreciated. Thanks!

Since you are new to LiPo's here is some excellent reading. Many of your questions will be answered.
https://sites.google.com/site/tjingu...arging-how-tos

Also so far most of the suggestions you have received prior to this are based on an "if" as in "if a cell is low".

You really need to replace your charger with one that removes the "if" and provides you with the information you need. For example:
http://www.usastore.revolectrix.com/...llpro-Multi4_3
This charger will provide you with the:
Charging current
Pack Voltage
Individual cell voltages
Milliamps returned to the pack

There are cheaper chargers available but this is a good one for starters.

Glen


All times are GMT -5. The time now is 09:01 AM.