Kraton Should i switch to xt90 connectors?

[Surchaufeur]

What brand? 40C is pretty low, I wouldn't run a battery that said less than 60C. Those numbers aren't real, but it at least gives you something to compare against other batteries from the same manufacturer. I.e. if a company makes "60C" batteries and "100C" batteries, the 100C batteries are going to be higher quality. It's not really 100C, but it's definitely higher than the 60C batteries.

You sure 40c is low?:c

 

[jondilly1974]

I don’t own a battery that is rated under 50C and the one 50C is a 2S lipo from my Mega that I don’t even use anymore.

 

[Surchaufeur]

Well is it that bad running those baterries i have two of them;-;
Never thought the C rating was an issue

 

[olds97_lss]

You sure 40c is low?:c

The BLX185 manual says the minimum you should use is 35C 5000mah. Which I believe comes out to 175Amps. So if you went smaller capacity, you would have to go higher C. If you had higher capacity, you could run lower C.

The C rating is relative to the capacity of the pack, so 40C may be ok.

Amps = C * capacity in Ah

4000mah = 4 Ah
175/4 = 43.75C

5000mah = 5 Ah
175/5 = 35C

6200mah = 6.2 Ah
175/6.2 = 28.2C

So my 5000mah 50C are capable (in theory) of 250A output continuous.
My 6200mah 50C are capable (again, in theory) of 310A output continuous.

However, when I run the packs back to back, I can really feel that the 6200mah packs perform better overall. I feel better punch out of them in general throughout the run.

 

[razorrc]

The C numbers are not real. They’re made up by the manufacturer.

 

[olds97_lss]

The C numbers are not real. They’re made up by the manufacturer.

Yeah, kind of like nitro engine hp numbers.

Still, from the same mfr, should be somewhat comparable to each other. Then again, who knows.

All I know for sure is the 2 25C 3S 5000mah packs I got from traxxas did not do well in the same setup as the 50C HRB packs. Supposedly traxxas has 2 kinds of 25C packs... old and new. Old were bad, new supposed to be good. Regardless, I'm not spending traxxas money on lipo's anymore.

 

[Surchaufeur]

Yeah, kind of like nitro engine hp numbers.

Still, from the same mfr, should be somewhat comparable to each other. Then again, who knows.

All I know for sure is the 2 25C 3S 5000mah packs I got from traxxas did not do well in the same setup as the 50C HRB packs. Supposedly traxxas has 2 kinds of 25C packs... old and new. Old were bad, new supposed to be good. Regardless, I'm not spending traxxas money on lipo's anymore.

I have someone who says traxxas lipo are the best because quality and when i was a nub and i dissagree he started being bad at me. Traxxas lipo are way over priced and they are soft packs something i may jever use on an rc car for bashing pupases

 

[arrmadillo]

I have someone who says traxxas lipo are the best because quality and when i was a nub and i dissagree he started being bad at me. Traxxas lipo are way over priced and they are soft packs something i may jever use on an rc car for bashing pupases

Traxxas lipos are not the best and definitely overpriced. They are rated at 25c and IMO junk.

Early this year I bought a Rustler VXL 4x4 and TRX lipo before I discovered Arrma. I bought their 5000 mah short pack for the Rustler because I though I had to run their batteries because of the plug thing. Didn't know ant better.

Turns out these short red lable packs are junk. They puff right out of the box and if you put load on them good luck. Their website has nothing but horror stories on the short red packs.

I've heard the black lable regular (long) packs faired better than the older red lable longs.

Anyway when I found out I didn't have to run their lipos because of the new plugs I sold the 5000 short at a loss unused.

TRX tries to trick newbs to run their lipos and "smart chargers" because of their new plugs!!

 

[Surchaufeur]

Traxxas lipos are not the best and definitely overpriced. They are rated at 25c and IMO junk.

Early this year I bought a Rustler VXL 4x4 and TRX lipo before I discovered Arrma. I bought their 5000 mah short pack for the Rustler because I though I had to run their batteries because of the plug thing. Didn't know ant better.

Turns out these short red lable packs are junk. They puff right out of the box and if you put load on them good luck. Their website has nothing but horror stories on the short red packs.

I've heard the black lable regular (long) packs faired better than the older red lable longs.

Anyway when I found out I didn't have to run their lipos because of the new plugs I sold the 5000 short at a loss unused.

TRX tries to trick newbs to run their lipos and "smart chargers" because of their new plugs!!

I had a traxxas rustler 4x4 as my first rc and was horrible and sold the think was making me more depress and i got myself an kraton 4s

 

[Jimbobjr]

I run 35-50 c batteries all the time in my 4 6s arrmas. They get hot, big deal. Also have a big Graphene it gets hot too, it’s summertime around here anyway. If you can still touch it long enough to get it unplugged after a run than it’s fine imo. No expert here but I do own maybe a dozen lipos of various kinds run them all to lvc with no problems. They get hot, when you think of what is transpiring under the body in these trucks it’s a wonder they all don’t catch fire.

 

[SrC]

Lipos just get hot. I agree. I get 150 deg. F lipo temps when ambients are above 70F for sure. Regardless of the C rating. C ratings should only be used as a reference when comparing lipos within same Brand. IMO. Cr. is a false perception to many. It is not a regulated spec. within the lipo industry. It is a false marketing 'Number'. And a lot of lipo mfrs. get away with bogus claims. The higher the C the more money mfrs. get for it. Lipo's C can be tested. And independent comparisons have been made among different brands. It turns out that they are all false. But the better brands come within 20% of spec. And that seems to be the best you will get. And considered "good" enough. Remember Mah enters into that C equation.
As for Traxxas lipo's..... their chargers , their plugs....their way is best concept...don't get me started please.

 

[Jerry-rigged]

I’m telling you that heat is caused by voltage sag. It’s a matter of fact. You can try to deny it, but that’s the root cause. Find out why and you will know how to fix it. Could be a bad cell. Could be a bad wire. Could be a faulty mosfet. Lots of possibilities.

Heat is caused by amps, not voltage sag. Bad batteries will heat the battery, not the wire. Bad solder or bad plug or undersized plug can make the wire hot, it will hottest at the plug.

With modern ESC, if you have bad voltage sag, the ESC will LVC before the voltage sag can cause Brown out issues.

 

[SrC]

All soldered joints in a circuit create resistance. Any flawed joint that creates higher than normal resistance in that circuit will cause more heat along that circuit. Amp flow is retarded. You get a bottleneck. (hence heat) At some point failure results.
I tried to keep it simple.
XT90's EC5's etc, are all basically bullet connectors. (4-5mm) Just in a different package. The bullets themselves can handle the amps. How well they are soldered is the key. No matter the type of connector. I find that the best setup is the shortest length (feasibly possible) using low # guage wiring (10 AG) that's soldered well, achieves the best efficiency. Hence lowered heat across its respective circuit. The longer the wire, the more resistance under load you will get.
I noticed some high end ESC's will use 10 gauge on the pos. and 12 gauge on the neg. for battery leads. Not common however. But there is a reason. That's another topic....

 

[olds97_lss]

Traxxas lipos are not the best and definitely overpriced. They are rated at 25c and IMO junk.

Early this year I bought a Rustler VXL 4x4 and TRX lipo before I discovered Arrma. I bought their 5000 mah short pack for the Rustler because I though I had to run their batteries because of the plug thing. Didn't know ant better.

Turns out these short red lable packs are junk. They puff right out of the box and if you put load on them good luck. Their website has nothing but horror stories on the short red packs.

I've heard the black lable regular (long) packs faired better than the older red lable longs.

Anyway when I found out I didn't have to run their lipos because of the new plugs I sold the 5000 short at a loss unused.

TRX tries to trick newbs to run their lipos and "smart chargers" because of their new plugs!!

These were what I had, still have one but don't really use it in anything. It only fits in my eJato as it's a long pack that won't fit in my stampede. Since the other puffed and died, I don't intend on buying another to match with it in any of my big trucks that it actually fits in.
Part# 2872X

I wouldn't get them again.

 

[jondilly1974]

Heat is caused by amps, not voltage sag. Bad batteries will heat the battery, not the wire. Bad solder or bad plug or undersized plug can make the wire hot, it will hottest at the plug.

With modern ESC, if you have bad voltage sag, the ESC will LVC before the voltage sag can cause Brown out issues.

Amps are drawn. Voltage is pushed. Motors consume watts. When voltage sags, it pulls more amps to compensate.

For example if your motor needs 2500W and you’re running a 25V battery, it’s going to pull 100A. If your voltage sags to 22.8V, as it will do near the end of a pack, or if the pack has issues, then it will need to pull 110A to provide the same wattage output. If your voltage sags too far, then the amperage will spike.

 

[SrC]

These were what I had, still have one but don't really use it in anything. It only fits in my eJato as it's a long pack that won't fit in my stampede. Since the other puffed and died, I don't intend on buying another to match with it in any of my big trucks that it actually fits in.
Part# 2872X

I wouldn't get them again.

They cant be balanced charged except on a Traxxas charger. Disect them and install your own balance leads. probably not worth it.

 

[Jerry-rigged]

Amps are drawn. Voltage is pushed. Motors consume watts. When voltage sags, it pulls more amps to compensate.

For example if your motor needs 2500W and you’re running a 25V battery, it’s going to pull 100A. If your voltage sags to 22.8V, as it will do near the end of a pack, or if the pack has issues, then it will need to pull 110A to provide the same wattage output. If your voltage sags too far, then the amperage will spike.

That 2500w is not a constant. The motor can only make that power if it has full voltage at full amps. The motor has an internal amp limit (resistance) and a volt limit (insulation) If a motor maxes out at 100a, lowering the volts won't make it draw more amps. What happens at the end of the pack is that as voltage sags, the you get longer (time) at a lower power (watts) at the same amps. Amps makes heat, so more time, at same amps = more heat.

If this is what you were trying to say a few posts back, I agree. But then you threw in the "bad cell" causing sag into the argument. But a bad cell will either trip LVC early, or burn the car down (different kind of heating problems ?)

As for the plugs, and bad solder joints, yeah, I was trying to keep it simple. Bad solder, undersized plug, both add resistance which adds heat. The wire is probably not heating itself, it is absorbing heat from the plug/solder. Same as when you are soldering a new plug on a wire, and 3" away the wire may be too hot to hold...

 

[olds97_lss]

They cant be balanced charged except on a Traxxas charger. Disect them and install your own balance leads. probably not worth it.

I did, after that photo as I sold off the traxxas charger and didn't feel like screwing around with the adapters.