Community
Wiki Posts
Search
Like Tree2Likes
  • 1 Post By billdelong
  • 1 Post By gigaplex

Lipo Battery

Thread Tools
 
Search this Thread
 
Old 03-21-2022 | 04:38 PM
  #1  
Thread Starter
Tech Initiate
 
Joined: Mar 2022
Posts: 22
From: Hong Kong
Smile Lipo Battery

Hi Everyone,
Can anyone tell me if a 6s lipo 60C 5000 mAh can be connected in series with a 4s lipo 60C 5000 mAh to provide a power bank of 10s? Remarks: they have different maximum burst discharge rates, i.e. 6s (120C) and 4s (100C).
Many thanks in advance.
Otto
Otto_Lee is offline  
Old 03-21-2022 | 04:45 PM
  #2  
bmwjoon's Avatar
Tech Adept
iTrader: (1)
 
Joined: Oct 2021
Posts: 204
From: Jersey as in JERRRRRZEEEEEE
Default

You can do it, but as the battery discharges the cells with less internal resistance will do more work ie. the cells will discharge at different rates.
bmwjoon is offline  
Old 03-21-2022 | 04:49 PM
  #3  
Thread Starter
Tech Initiate
 
Joined: Mar 2022
Posts: 22
From: Hong Kong
Default

Noted with thanks.
Otto_Lee is offline  
Old 03-21-2022 | 04:58 PM
  #4  
gigaplex's Avatar
Tech Champion
iTrader: (2)
 
Joined: Dec 2015
Posts: 7,766
From: Melbourne, VIC
Default

Originally Posted by bmwjoon
You can do it, but as the battery discharges the cells with less internal resistance will do more work ie. the cells will discharge at different rates.
In parallel, that would happen. In series, they have identical current load.
gigaplex is offline  
Old 03-21-2022 | 06:37 PM
  #5  
Thread Starter
Tech Initiate
 
Joined: Mar 2022
Posts: 22
From: Hong Kong
Default

Does it mean that it wouldn't matter if the cells have different max burst discharge rates?
Otto_Lee is offline  
Old 03-21-2022 | 07:58 PM
  #6  
gigaplex's Avatar
Tech Champion
iTrader: (2)
 
Joined: Dec 2015
Posts: 7,766
From: Melbourne, VIC
Default

Originally Posted by Otto_Lee
Does it mean that it wouldn't matter if the cells have different max burst discharge rates?
It'll only matter if you're getting anywhere close to those discharge rates. Assume the combined pack has a discharge rate of the lowest rated cell in the series.
gigaplex is offline  
Old 03-22-2022 | 07:55 AM
  #7  
Tech Champion
iTrader: (33)
 
Joined: Mar 2011
Posts: 6,410
From: Austin,TX
Default

While this CAN be done, I don't recommend doing it unless you buy both packs brand new and make sure they are identical spec with same C rating and capacity, treating the combined cells as an individual pack and rotating the series connection between each use, more information here:
https://www.smc-racing.net/index.php...egory&path=166

I once damaged a brand new pack when I tried to run it in series with an older pack and the new pack over drained and ballooned on me
MX304 likes this.
billdelong is offline  
Old 03-22-2022 | 08:14 AM
  #8  
the rc guy's Avatar
Tech Elite
 
Joined: Aug 2016
Posts: 3,433
From: Detroit
Default

ive done enough runs with series batteries and always found that the battery that is the negative feed battery will always drain faster than the others no matter what the ir is, ( electronic gurs will say different i have real life hands on experience and a dead battery or 2)
0invest in some simple battery buzzers it will save you the cost f replacing a battery, its like $5 each.
the rc guy is offline  
Old 03-22-2022 | 02:30 PM
  #9  
Tech Rookie
 
Joined: Mar 2022
Posts: 1
Default

oh really
stevetech is offline  
Old 03-22-2022 | 05:52 PM
  #10  
gigaplex's Avatar
Tech Champion
iTrader: (2)
 
Joined: Dec 2015
Posts: 7,766
From: Melbourne, VIC
Default

Why would the negative terminal battery drain faster? Kirchhoff's first law states that the current will be identical through the cells. If that actually happened, then you'll have the same exact problem internal to multi cell packs.
mrreet2001 likes this.
gigaplex is offline  
Old 03-22-2022 | 08:19 PM
  #11  
Tech Champion
iTrader: (33)
 
Joined: Mar 2011
Posts: 6,410
From: Austin,TX
Default

Originally Posted by gigaplex
Why would the negative terminal battery drain faster? Kirchhoff's first law states that the current will be identical through the cells. If that actually happened, then you'll have the same exact problem internal to multi cell packs.
I believe it's because the mass of the electron (negative charge) is only 0.0005486 amu and the proton (positive charge) is much heavier at 1.007276 amu which suggests energy flows from the negative terminal.... If I didn't observe the same phenomena myself, I would raise the same question, but there's a great discussion here which debates the flow of electricity where many scientists argue both directions:
https://www.douglaskrantz.com/ElecElectricalFlow.html

To summarize, any discussion about electricity from this post forward is a rabbit hole... the article I linked above from SMC is everything the OP needs to operate his 10S in series safely
billdelong is offline  
Old 03-22-2022 | 11:37 PM
  #12  
gigaplex's Avatar
Tech Champion
iTrader: (2)
 
Joined: Dec 2015
Posts: 7,766
From: Melbourne, VIC
Default

Originally Posted by billdelong
I believe it's because the mass of the electron (negative charge) is only 0.0005486 amu and the proton (positive charge) is much heavier at 1.007276 amu which suggests energy flows from the negative terminal.... If I didn't observe the same phenomena myself, I would raise the same question, but there's a great discussion here which debates the flow of electricity where many scientists argue both directions:
https://www.douglaskrantz.com/ElecElectricalFlow.html

To summarize, any discussion about electricity from this post forward is a rabbit hole... the article I linked above from SMC is everything the OP needs to operate his 10S in series safely
Protons don't leave the cells, or even the lithium atom. The same electrons pass through all cells in the series circuit. The cells are chemically isolated from each other.
I tried viewing the article you linked but the site appears to be down.
gigaplex is offline  

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.