Lipo Help! (New and searching)
12-13-2014, 08:34 PM
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Lipo Help! (New and searching)
Hi folks,
I've always ran Nimh batteries. I've now (finally) decided I would like to try out one of the cold blooded beasts and see what everyone's been raving about. I'm scouting the web as I usually like to research on my own accord but I find myself becoming more and more confused on the topic.
I'm searching for a 2s Lipo, 5000mah minimum for my rusty (hopefully for Christmas
)
I'm starting to get hung up on "C" ratings. Traxxas online pdf states the Velineon ESC being 200A capable while I hear alot of other folks saying realistically it's 100A?
Thus far I've found no info to the max amp draw of the Velineon 3500 motor.
In short I'm looking for a best bang for the buck battery while staying within the safe limitations of my electronics. Any and all help is greatly appreciated. Thanks in advance guys!!
I've always ran Nimh batteries. I've now (finally) decided I would like to try out one of the cold blooded beasts and see what everyone's been raving about. I'm scouting the web as I usually like to research on my own accord but I find myself becoming more and more confused on the topic.
I'm searching for a 2s Lipo, 5000mah minimum for my rusty (hopefully for Christmas
)I'm starting to get hung up on "C" ratings. Traxxas online pdf states the Velineon ESC being 200A capable while I hear alot of other folks saying realistically it's 100A?
Thus far I've found no info to the max amp draw of the Velineon 3500 motor.
In short I'm looking for a best bang for the buck battery while staying within the safe limitations of my electronics. Any and all help is greatly appreciated. Thanks in advance guys!!
12-13-2014, 10:00 PM
#2
"Traxxas online pdf states the Velineon ESC being 200A capable while I hear alot of other folks saying realistically it's 100A?"
Classic example of Marketing BS vs Reality.
I understand your confusion on C ratings, as it kind of depends on what C rating you're discussing. You also need a good M-BS detector. If it is a battery's discharge rating, the one they usually put on the label, higher is better. All of Traxxas' Lipos are rated 25C on the label. They SAY the packs are capable of 50C. If that was true, don't you think they'd put 50C on the label? BS-detector says, "EGH! Somethin' stinks!" That said, Traxxas Lipos performed well against Turnigy and Gens Ace in a Big Squid Lipo shootout.
Theoretically, you multiply the pack's milli-amp-hour rating (dropping the zeros) by the C rating to give you the pack's max Amp output. Think of it as "how much juice in a given instant can this pack supply?" The higher the C rating, the more power the pack can easily supply without being stressed. You wouldn't, for example, want to use a 25C pack in a 1/8 scale 4wd buggy that weighs 8lbs. and has a 200A ESC with a 550-sized 4-pole brushless motor. The system would try to draw more Amps than the pack can easily supply, so it gets hot. In all things electronic, Heat Is Bad. You would want to run at least a 50C pack in that 8lb buggy.
Then there is the C rating that refers to the pack's Charging Rate. Usually, 1C is the norm. That is: Charge at 1Amp for every 1000mah of a given pack. So a 3000mah pack you'd charge at 3Amps, a 5000mah at 5Amps.
Gens Ace Lipos are good, I use them. I get the 5000mah 40C-50C 2S hardcase packs. Usually around $45ea. I've heard good things about Turnigy, and SPC. I've heard about SPC Lipos as little as $25 for a 40C 5000mah!
The most important thing about lipos is, always use a good connector like Traxxas or Deans. NEVER EVER Tamiya Molex connectors.
As for amp draw ratings on motors, it is something not commonly published. Kind of a pisser when one is trying to match a given motor to an ESC or vice-versa. I dunno what the big flippin' secret is.
Classic example of Marketing BS vs Reality.
I understand your confusion on C ratings, as it kind of depends on what C rating you're discussing. You also need a good M-BS detector. If it is a battery's discharge rating, the one they usually put on the label, higher is better. All of Traxxas' Lipos are rated 25C on the label. They SAY the packs are capable of 50C. If that was true, don't you think they'd put 50C on the label? BS-detector says, "EGH! Somethin' stinks!" That said, Traxxas Lipos performed well against Turnigy and Gens Ace in a Big Squid Lipo shootout.
Theoretically, you multiply the pack's milli-amp-hour rating (dropping the zeros) by the C rating to give you the pack's max Amp output. Think of it as "how much juice in a given instant can this pack supply?" The higher the C rating, the more power the pack can easily supply without being stressed. You wouldn't, for example, want to use a 25C pack in a 1/8 scale 4wd buggy that weighs 8lbs. and has a 200A ESC with a 550-sized 4-pole brushless motor. The system would try to draw more Amps than the pack can easily supply, so it gets hot. In all things electronic, Heat Is Bad. You would want to run at least a 50C pack in that 8lb buggy.
Then there is the C rating that refers to the pack's Charging Rate. Usually, 1C is the norm. That is: Charge at 1Amp for every 1000mah of a given pack. So a 3000mah pack you'd charge at 3Amps, a 5000mah at 5Amps.
Gens Ace Lipos are good, I use them. I get the 5000mah 40C-50C 2S hardcase packs. Usually around $45ea. I've heard good things about Turnigy, and SPC. I've heard about SPC Lipos as little as $25 for a 40C 5000mah!
The most important thing about lipos is, always use a good connector like Traxxas or Deans. NEVER EVER Tamiya Molex connectors.
As for amp draw ratings on motors, it is something not commonly published. Kind of a pisser when one is trying to match a given motor to an ESC or vice-versa. I dunno what the big flippin' secret is.
Last edited by EXT2Rob; 12-13-2014 at 10:08 PM.
12-13-2014, 10:11 PM
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I assume you're using the VXL-3S. These batteries would be nice. But, if you were to go with another brand, keep this in mind. This also explains C ratings very well.
Straight from SMC's Facebook page. I recommend Venom LiPOs, as they have the real C ratings, not this fluff he explains in the article
2S Venom LiPO; http://www.atomikrc.com/collections/...-with-uni-plug
3S Venom LiPO; http://www.atomikrc.com/collections/...1-1-5000mah-3s
I'm making this post to try and help educate everyone about how crazy the Lipo ratings have become and are pretty much useless. I know most of you will appreciate this post and some will think I'm just using this to promote SMC but this is really to open some eyes.
First let me explain the fact that their is no true C rate testing standards. Some factories use mAh retention and others use heat and voltage curve to determine the C rate. Every factory knows the C rate of their cells based on one of these 2 methods of C rate testing.
When I started testing and buying Lipos 8 years ago the C rates were 10 to 20C for car packs. At that time the factories were giving true C rates based on their testing method for C rate. Within a few years C rates doubled but this was just marketing to try and sell more packs and make more money. Now 8 years later it's even crazier with some outrageous C rate claims and mAh has also started to increase on the labels but not on the cells. In my opinion 80% or more of the packs being sold in car market today have a true C rate of 15 to 25C using the heat and voltage curve method for C rate testing. Using the mAh retention you can add 5C. There are some 30C and 35C packs available but these are very rare and cost more to make.
C rate is the amp rate at which the cell/pack can be discharged at. So a 5000-20C can do 100amps. A 7200-20C can do 144 amps and so on. IR(Internal Resistance) is directly related to a cells ability to handle amp loads. So it's not possible for a pack to have higher C rate and higher IR. This means a 7200-20C has to be lower in IR than a 5000-20C. The size of the cell also limits it's mAh or C rate/IR. In car packs with hard cases we're limited by the size of the case. This means if you want to increase mAh you must increase IR or vice versa. A 7200-25C will have higher IR than a 6000-35C. The 7200 will be able to do 180 amps and the 6000 will be able to do 210 amps. Only way the 6000 can provide more amps is to have lower IR.
Now that we know this if true C ratings would exist the consumer/racer would be able to know what pack better suits his needs. Unfortunately this isn't the case so there really is no way for the customer/racer to know. SMC is no different than others as we also use inflated C rates as we have no choice. If we would use true C rates we would be out of business. What we do try and do that is different is make sure that our ratings mean something. For example our 5000-40C will have higher IR than our 5000-50C and so on.
Here is something that I find interesting and frustrating at the same time. Some of our competitors buying the same packs we do offer them with higher ratings. This leads to some customers buying these higher priced packs instead of ours. Here are 2 examples. The 4400-60C shorty which we sell for 29.95 is being offered as a 4600-90C at 44.95 and it's the exact same pack that we offer. The 7200-60C-2S pack we offer for 39.95 is being offered as a 7600-75C for 64.95.
Something else interesting is that a customer who bought one of our 5000-40C-2S packs at 24.95 compared it to a 5450-120C-2S pack at 129.99 and told me that our 40C pack ran longer and faster in the same vehicle and the 120C pack was new to make a fair comparison.
Now that we know C rates are all made up and it's actually getting a bit ridiculous to claim even higher C rates it seems like in the past few years mAh is now what is being inflated. Recently I tested a 7000-1S pack that only put out 6222mAh. I will admit some of our packs also have a bit lower mAh than claimed but this is due to the model being improved to provide lower IR. If you drop the IR the mAh drops.
I hope this post can help some of you not fall for all the BS and hype and don't be surprised if SMC starts releasing higher rated packs to try and keep up as it's very frustrating to under rate our packs and lose sales.
First let me explain the fact that their is no true C rate testing standards. Some factories use mAh retention and others use heat and voltage curve to determine the C rate. Every factory knows the C rate of their cells based on one of these 2 methods of C rate testing.
When I started testing and buying Lipos 8 years ago the C rates were 10 to 20C for car packs. At that time the factories were giving true C rates based on their testing method for C rate. Within a few years C rates doubled but this was just marketing to try and sell more packs and make more money. Now 8 years later it's even crazier with some outrageous C rate claims and mAh has also started to increase on the labels but not on the cells. In my opinion 80% or more of the packs being sold in car market today have a true C rate of 15 to 25C using the heat and voltage curve method for C rate testing. Using the mAh retention you can add 5C. There are some 30C and 35C packs available but these are very rare and cost more to make.
C rate is the amp rate at which the cell/pack can be discharged at. So a 5000-20C can do 100amps. A 7200-20C can do 144 amps and so on. IR(Internal Resistance) is directly related to a cells ability to handle amp loads. So it's not possible for a pack to have higher C rate and higher IR. This means a 7200-20C has to be lower in IR than a 5000-20C. The size of the cell also limits it's mAh or C rate/IR. In car packs with hard cases we're limited by the size of the case. This means if you want to increase mAh you must increase IR or vice versa. A 7200-25C will have higher IR than a 6000-35C. The 7200 will be able to do 180 amps and the 6000 will be able to do 210 amps. Only way the 6000 can provide more amps is to have lower IR.
Now that we know this if true C ratings would exist the consumer/racer would be able to know what pack better suits his needs. Unfortunately this isn't the case so there really is no way for the customer/racer to know. SMC is no different than others as we also use inflated C rates as we have no choice. If we would use true C rates we would be out of business. What we do try and do that is different is make sure that our ratings mean something. For example our 5000-40C will have higher IR than our 5000-50C and so on.
Here is something that I find interesting and frustrating at the same time. Some of our competitors buying the same packs we do offer them with higher ratings. This leads to some customers buying these higher priced packs instead of ours. Here are 2 examples. The 4400-60C shorty which we sell for 29.95 is being offered as a 4600-90C at 44.95 and it's the exact same pack that we offer. The 7200-60C-2S pack we offer for 39.95 is being offered as a 7600-75C for 64.95.
Something else interesting is that a customer who bought one of our 5000-40C-2S packs at 24.95 compared it to a 5450-120C-2S pack at 129.99 and told me that our 40C pack ran longer and faster in the same vehicle and the 120C pack was new to make a fair comparison.
Now that we know C rates are all made up and it's actually getting a bit ridiculous to claim even higher C rates it seems like in the past few years mAh is now what is being inflated. Recently I tested a 7000-1S pack that only put out 6222mAh. I will admit some of our packs also have a bit lower mAh than claimed but this is due to the model being improved to provide lower IR. If you drop the IR the mAh drops.
I hope this post can help some of you not fall for all the BS and hype and don't be surprised if SMC starts releasing higher rated packs to try and keep up as it's very frustrating to under rate our packs and lose sales.
2S Venom LiPO; http://www.atomikrc.com/collections/...-with-uni-plug
3S Venom LiPO; http://www.atomikrc.com/collections/...1-1-5000mah-3s
12-14-2014, 11:41 AM
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I can't thank you two enough, you guys are brilliant!
Nice find collector1231, thanks for posting. Unfortunately marketing BS has its stamp on most products today, I'm not surprised to see this going on with products in the hobby. Talk about honesty, GOOD FOR THEM!
I went with a pack from SPC, scouted the web only to find good things about them. Thanks for introducing me to them EXT2Rob.
Backwards buying here :P now I just need a charger, something effective yet simple, what are your thoughts on these?
http://www3.towerhobbies.com/cgi-bin...&I=LXEVSD&P=ML
http://www3.towerhobbies.com/cgi-bin...&I=LXCADF&P=ML
http://www3.towerhobbies.com/cgi-bin...?&I=LXEFAL&P=7
The Duratrax says its a "balancing charger" while the Traxxas states "with ID" anyone familiar with such terms? As always, thanks gentlemen!!
Nice find collector1231, thanks for posting. Unfortunately marketing BS has its stamp on most products today, I'm not surprised to see this going on with products in the hobby. Talk about honesty, GOOD FOR THEM!
I went with a pack from SPC, scouted the web only to find good things about them. Thanks for introducing me to them EXT2Rob.
Backwards buying here :P now I just need a charger, something effective yet simple, what are your thoughts on these?
http://www3.towerhobbies.com/cgi-bin...&I=LXEVSD&P=ML
http://www3.towerhobbies.com/cgi-bin...&I=LXCADF&P=ML
http://www3.towerhobbies.com/cgi-bin...?&I=LXEFAL&P=7
The Duratrax says its a "balancing charger" while the Traxxas states "with ID" anyone familiar with such terms? As always, thanks gentlemen!!
12-14-2014, 09:09 PM
#6
The Traxxas "ID" is for for Traxxas batteries, somehow it knows what model Traxxas battery is hooked up and automatically configures the charge settings for you. It doesn't work for other brands, you have to manually configure the charge setting for other brands. I don't know what's out there for more basic chargers, I do know ExtRob has an inexpensive favorite that others like as well. Avoid that last Duratrax one you linked though, it only has a 20w output, that's a slow 3amp charge for a 2s and even slower for higher voltage batteries.
Collector1231, I've been preaching the same thing about C ratings for years ever since BigSquid showed a video of a lipo going up in smoke while trying to pull the amps its c rating said it could put out. Thanks for posting that.
Collector1231, I've been preaching the same thing about C ratings for years ever since BigSquid showed a video of a lipo going up in smoke while trying to pull the amps its c rating said it could put out. Thanks for posting that.
12-15-2014, 09:00 AM
#7
For general use Hobbyking T682 AC, iMax B6AC ,Thunder AC680 are good choices. I use a copy of the iMax B6AC 80 watt charger that I got on eBay. They come in many similar shapes; same specs; same 4 button programing flow, but with different ink printed on them (re-branded) as shown in the pictures.
Most have the internal balancing ports built into the side of charger and some have an external individual cell connector board, like the Thunder AC680. I had 4 of the B6AC80, but I sold one because the two that get used daily haven't given me any problems. One is kept for a spare.
Most have the internal balancing ports built into the side of charger and some have an external individual cell connector board, like the Thunder AC680. I had 4 of the B6AC80, but I sold one because the two that get used daily haven't given me any problems. One is kept for a spare.
Last edited by RustyUs; 12-15-2014 at 09:29 AM.
12-15-2014, 02:45 PM
#8
Sac, I wouldn't get any of the chargers you linked, to be honest. I would only consider the Traxxas model if you were going to buy a Traxxas vehicle and Traxxas Lipos. The "ID" thing is a new version of the Traxxas battery connector that includes the balance taps. That's how the charger detects what cell config, 2S or 3S, the pack has, and charges accordingly. Consequently, with plugs like that, you have to use the ID Charger. I like that it eliminates the fragile balance wires, but you end up with a proprietary system, which I don't like.
And, for the same money, you get a better charger, one with a digital readout, so you can see exactly what your cell voltages are. You know exactly what's going on at all times. WAY better IMO.
Eh, for the record, I have no experience with SMC packs. I just heard about them recently, and I plan on buying one or two to see what they're like. Let us know how you like it. And ya know...if you really get the bug bad, yer gonna want more than one pack!
And, for the same money, you get a better charger, one with a digital readout, so you can see exactly what your cell voltages are. You know exactly what's going on at all times. WAY better IMO.
Eh, for the record, I have no experience with SMC packs. I just heard about them recently, and I plan on buying one or two to see what they're like. Let us know how you like it. And ya know...if you really get the bug bad, yer gonna want more than one pack!
12-16-2014, 12:01 AM
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Thanks Rob, no Traxxas lipos for me, and thanks for the recommendations Rusty. I'll let you know how the SMC pack is once it arrives. As far as chargers go I'm thinking on going with either one of these guys:
http://www.hobbypartz.com/thac6smbac...ProductReviews
http://www.hobbypartz.com/73p-ac680-...ProductReviews
Thoughts please! Sorry lol, forgive a cheap bast**d like me, I'm sure you guys cringe a little every time you see these cheap junkers haha.
http://www.hobbypartz.com/thac6smbac...ProductReviews
http://www.hobbypartz.com/73p-ac680-...ProductReviews
Thoughts please! Sorry lol, forgive a cheap bast**d like me, I'm sure you guys cringe a little every time you see these cheap junkers haha.
12-16-2014, 07:49 AM
#10
Not cheap junkers at all! I have the AC680 and love it! my buddy has BOTH. The only difference between those two is the AC6 is 50W and the 680 is 80W and has the fan. The 680 is slightly more powerful. I'm totally behind buying so-called "cheap Chinese junk" as long as it does what it's supposed to. Get the AC680.
