Lipo battery and charger

[southernsoftie]

Apologies for bombarding this forum with newbie questions but I've just bought a Kong Charger and a lipo 7.4v. I've read that it's good to discharge the battery after use to 3.7v for storage? My Kong charger doesn't have a discharge mode (at least not that I can see) so should I invest in a Turnigy 6 Accucel or should I just use my common sense and change the battery once the ROF reduces. I've heard too many horror stories abut Lipo's to take the risk. Any advice welcome.

Thanks

 

[zetec]

You should store at 7.4 volts which sounds strange but a fully charged 2 cell lipo will be at 8.4 volt..you are partly correct in 3.7 volt per cell, you have 2 cells hence 7.4 volt. easy way to do things is to charge the lipo with a charger to 8.4 volts a day or so before you play. When you have used the battery dont charge it till you need it again, problem start when you leave stored fully charged for weeks on end.

Storing charged can mean the cells start to swell, I dont me a little, this is normal, the cell will increase by about 50% thickness when buggered. They will still work but not worth the risk...

My son races RC cars where the lipos take a real hammering and no horrors yet, just dont over charge or run flat.

As a guide we use about 250 - 300mA per hour max...this means we can use 1800mah 2 cell battery all day normally.

You can get a decent little charger which will do everything like the Imax B6 for not a lot of £££.

 

[southernsoftie]

You should store at 7.4 volts which sounds strange but a fully charged 2 cell lipo will be at 8.4 volt..you are partly correct in 3.7 volt per cell, you have 2 cells hence 7.4 volt. easy way to do things is to charge the lipo with a charger to 8.4 volts a day or so before you play. When you have used the battery dont charge it till you need it again, problem start when you leave stored fully charged for weeks on end.

Storing charged can mean the cells start to swell, I dont me a little, this is normal, the cell will increase by about 50% thickness when buggered. They will still work but not worth the risk...

My son races RC cars where the lipos take a real hammering and no horrors yet, just dont over charge or run flat.

As a guide we use about 250 - 300mA per hour max...this means we can use 1800mah 2 cell battery all day normally.

You can get a decent little charger which will do everything like the Imax B6 for not a lot of £££.

Cheers for taking the time to reply mate, really helpful

 

[Ian_Gere]

Imax B6 and Turnigy Accucell 6 are the same machine with different branding. I have an Accucell 6 and it has all the bells and whistles you could ever want. I went the whole hog and ordered the USB connector and software from the USA, i think - i forget, could have been HK, so I can watch its progress on my lappy. TBH I have very little idea what I could or should do about what I'm looking at, but it's pretty! It didn't actually cost much either. You can also get a temperature thingumajig that plugs in the same port as the USB converter flibbet...

I had money spare at the time and I wanted a charger that could balance LiPo's, so I went for it. I don't think I actually need most of what it can do, but at least I can relax in the knowledge that I can deal with just about any rechargeable battery I'm likely to use in the next 10 years. Unless you have the money spare, I'd take zetec's advice and not bother.

 

[southernsoftie]

Imax B6 and Turnigy Accucell 6 are the same machine with different branding. I have an Accucell 6 and it has all the bells and whistles you could ever want. I went the whole hog and ordered the USB connector and software from the USA, i think - i forget, could have been HK, so I can watch its progress on my lappy. TBH I have very little idea what I could or should do about what I'm looking at, but it's pretty! It didn't actually cost much either. You can also get a temperature thingumajig that plugs in the same port as the USB converter flibbet...

I had money spare at the time and I wanted a charger that could balance LiPo's, so I went for it. I don't think I actually need most of what it can do, but at least I can relax in the knowledge that I can deal with just about any rechargeable battery I'm likely to use in the next 10 years. Unless you have the money spare, I'd take zetec's advice and not bother.

Many thanks Ian. My Kong charger actually says its a 'balance' charger on its front - what does that actually mean, I haven't got a clue

 

[zetec]

If you have lipos with more than one cell they should be supplied with the main cable and another small plug connected with thinner cables. This plug, when connected to the charger, allows each cell to be charged independent of the others and allows the charger to "Balance" each cell to the same voltage rather than over charging one cell and leaving another low. I tend to balance charge every new battery first time I charge it and then every 5th or 6th time.

Your charger will also show you the voltage of each individual cell which is useful if you think a battery has failed due to a cell going down.

Have a look on Youtube for a video of how to use the charger, once you get the menus all will be clear.

 

[southernsoftie]

If you have lipos with more than one cell they should be supplied with the main cable and another small plug connected with thinner cables. This plug, when connected to the charger, allows each cell to be charged independent of the others and allows the charger to "Balance" each cell to the same voltage rather than over charging one cell and leaving another low. I tend to balance charge every new battery first time I charge it and then every 5th or 6th time.

Your charger will also show you the voltage of each individual cell which is useful if you think a battery has failed due to a cell going down.

Have a look on Youtube for a video of how to use the charger, once you get the menus all will be clear.

Tks mate, very helpful