Size of battery & alternatives

[Christopher Morris 2]

Hi, i am looking at a model that requires an 8 cell 3200mA minimum. Now i havant got an 8 cell charger, my one is only a 6 cell. What could the alternative be?. 2x4cell in series ? or, is this not the way.

Details of model motor & power:

Motor: 50mm 310 rev per volt - Propeller: 14x10 ~ 15x10
ESC: 60A -
Lipo Batteries: 8 cell 3200mA

Thanks

[Frank Skilbeck]

Yep that's what I do on a model that generates around 1800 watts, 2 x 5,000 mah 4s in series. I use 5.5mm connectors connect the two batteries together and then hook up to the ESC with the antispark connector last. Make sure your ESC can handle 8 cells as well, most can only go to 6 cells so you need to make sure that yours is OK on 8 cells.

Edited By Frank Skilbeck on 21/10/2019 17:24:19

[Christopher Morris 2]

Thanks for that. I noticed that some ESC are marked 80A Brushless ESC with 5A BEC (2~6S) does the 2~6 mean the equivalent of 12 cells & would be ok for 8 cells.
Presumably i am also best to charge the 2 battery's separately & not wile in series .

[Alan Gorham_]

2-6S means it is suitable for 2S upto 6S batteries. You may have to look for so-called HV or high voltage ESC to handle 8S or up.

[Christopher Morris 2]

thanks.  Turnigy dlux 80A HV Brushless ESC w/8A SBEC and Data Logging (2s~8s) £72.55 ouch! 

 

Edited By Christopher Morris 2 on 21/10/2019 21:28:43

[Brian Stevenson 1]

Posted by Christopher Morris 2 on 21/10/2019 19:30:02:

Presumably i am also best to charge the 2 battery's separately & not wile in series .

 

 

Yes, you can't put them in series when you only have a 6 cell charger. And of course charging them separately will take twice as long..

 

Two solutions.

A) Buy a 'parallel charging' board. You can get one from Overlander and there are other places too.

B) Make sure they are equally discharged (as you are flying them together in series they will be, roughly). Then:

Make up a 'parallel Y lead' and charge them together forgetting the balancing. You don't actually NEED to balance them every time you charge, every 10 or 20 charges will do. The charging 'protocol' is such that the charge tapers off gradually at the end and this will tend to roughly balance them, as the 'internal resistance' of each individual cell increases as the voltage reaches a maximum, so fuller ones will get less current anyway. I went two years (at least a hundred flights/charges) without balancing some at all, ever. And they are still fine. If you do this DON'T charge at more than a '2C' rate, though a '1.5C' or '1C' rate is better but not essenrial.

Edited By Brian Stevenson 1 on 21/10/2019 22:21:08

Edited By Brian Stevenson 1 on 21/10/2019 22:22:14

Edited By Brian Stevenson 1 on 21/10/2019 22:23:57

[Christopher Morris 2]

Thanks for all the great info guys. Your making my life a lot easer.

[Frank Skilbeck]

I also use these connectors to avoid the spark when connecting up setups greater than a 6s. The connector with the inline resistor is fitted to the ESC and made up last.