Turnigy rapid 4s 5500 mah 140c review

[Elmm]

Hello everyone just a quick review about this new turnigy packs , tested them out on sunday for the first time and i like them but not love them.
The good: beautifull looking and well built, light weight for its capacity rating , increrible runtime after 25 min of hard bashing my talion they where still going strong.
The bad: 12awg its not ideal for a 140c pack full stop, when it comes to raw power the turnigy heavy duty 60c 5000mah have more punch and i enjoy using them more .
In conclusion, would i buy them againg if i was racing? , yes, would i buy them for bashing fun?, no , the turnigy heavy duty 60c 5000mah are way more fun to use.

 

[rflx]

Hello everyone just a quick review about this new turnigy packs , tested them out on sunday for the first time and i like them but not love them.
The good: beautifull looking and well built, light weight for its capacity rating , increrible runtime after 25 min of hard bashing my talion they where still going strong.
The bad: 12awg its not ideal for a 140c pack full stop, when it comes to raw power the turnigy heavy duty 60c 5000mah have more punch and i enjoy using them more .
In conclusion, would i buy them againg if i was racing? , yes, would i buy them for bashing fun?, no , the turnigy heavy duty 60c 5000mah are way more fun to use.

Very cool to give us some insight, thanks!

I would be really interested in hearing about the durability of these packs. It uses 2 cells in parallel, right? Can those ever be properly balanced? If so, how does it work? If not: Isn't that pretty terrible in the long term?

 

[Elmm]

Hi rflx, the packs are wired as 1 4s pack and have a 4s balance lead, so they balance perfectly , ill will update on durability at 6 months and then a year , if you are planing to run your car at a 1/8 track where you need more control and good runtime they are amazing i use the 20tooth pinion on my talion and after the full run the lipos where just warm they didnt break a sweat.

 

[jondilly1974]

Hi rflx, the packs are wired as 1 4s pack and have a 4s balance lead, so they balance perfectly , ill will update on durability at 6 months and then a year , if you are planing to run your car at a 1/8 track where you need more control and good runtime they are amazing i use the 20tooth pinion on my talion and after the full run the lipos where just warm they didnt break a sweat.

What he is getting at is the individual packs are 4S2P packs. That means inside each pack there are 8 cells. Two parallel four cell packs. That’s what 4S2P stands for.

 

[rflx]

Hi rflx, the packs are wired as 1 4s pack and have a 4s balance lead, so they balance perfectly , ill will update on durability at 6 months and then a year , if you are planing to run your car at a 1/8 track where you need more control and good runtime they are amazing i use the 20tooth pinion on my talion and after the full run the lipos where just warm they didnt break a sweat.

Thanks, looking forward to hearing about it in 6 months
Lipo reviews are far too rare.

And yes, @jondilly1974 is exactly right about what I was asking. The pack has 8 cells and 4 balancing cables.. I assume they try to match the internal resistance of the parallel cells. But still, I imagine it cannot ever get balanced as well as a 1P pack.

 

[jkflow]

They are physically connected i. e. they will always balance perfectly.

 

[rflx]

They are physically connected i. e. they will always balance perfectly.

Can you explain how that works? What do you mean by "physically connected"?

As you might be able to tell, I'm pretty confused about how 2p Lipos work ?

 

[jkflow]

The packs are connected by wire. Just like the rest of the pack. Electrically invisible, no matter how many you place in parallel. Only physical differences is the packaging. There are no pro or cons for 1p vs 2p other than dimensions and complexity of manufacturing the pack. Of course, the more items the more chance for a weak link.

 

[jondilly1974]

Yeah I didn’t think that thru. Of course two parallel cells will always balance. They never get disconnected electrically.

 

[rflx]

The packs are connected by wire. Just like the rest of the pack. Electrically invisible, no matter how many you place in parallel. Only physical differences is the packaging. There are no pro or cons for 1p vs 2p other than dimensions and complexity of manufacturing the pack. Of course, the more items the more chance for a weak link.

Thank you! I think I get it at least partly now.

I remembered reading something about differences in internal resistance affecting the degradation of cells that are wired in parallel and got confused. I have found the publication again ( http://web.mit.edu/bazant/www/papers/pdf/Gogoana_2013_J_Power_Sources.pdf ) and I guess it has nothing to do with balancing and might not be applicable at all to LiPo cells.

Thanks for helping me learn, cheers!

 

[Elmm]

Sorry rflx i didnt understand your question and thanks jon and jk for your answers.

 

[jkflow]

Damage is a little weird on parallel packs. Typically, you will damage both cells when they are in parallel just like a single one but always exceptions to the rule.
In parallel, as soon as one is getting stressed the internal resistance increases of that one side. As a result, it will pull more on the 2nd side and most likelty stress it as well. They will always charge equally but charging is typically not where the damage occurs.
At the end of the day it's typically no better or worse than damaging a single cell. If they are badly matched cells it would be a concern but all these packs are manufactured the same nowadays.