Hey guys I know to use the Search Button and Google. But I dont think I am understanding Lipo Batteries Enuff.
I want to know more about the " C " Rating. I want to know The Higher the C rating the faster Or Stronger Current draw?? For example is a 30C battery better than a 20C??
If it is Will you see a difference on the track??? Is it Beneficial??
Also The Mah rating.. Is the Higher the Mah the Stronger the battery?? Or is the Mah just how much Capacity the Battery holds??? For example Is a 4800 Mah Battery Better than the 3400 Mah battery??
All the info and advice will help thank you. I just want to know this for when i race at my local track.
C rating can be thought of as the lipos discharge capability. If you have a 20C 5000mah its discharge capability is 20 x 5000/1000 = 100amps. The same capacity but 30C would have 30 x 5 = 150amps. So, there is a diff. It is indirectky influenced by the mah or capacity as you can see with how the discharge capability is calculated. A 40C 3400mah would have 136amps and have more discharge capability than a 20C 5000mah which would only be 100amps.
Where does it make a diff? It depends on the setuo you;re running and how many amps it needs. If you're running a heavy rc like a Flux, the higher C rating does make a diff you can see. If you're running a 5lb onroad car, it is prob not going to make a visible diff. They other way the C rating shows up is in lipo temp - if your batt is having to supply 80-90 of its C capability a lot of the time, it will run hot which is not what you want for long life. If you size teh C rating so the setup is using a lower percentage of its capability, it will run cooler and have a longer life.
There are some good links here, read teh one from the Heli site, it will help with understanding - Lipo for newbies
C rating can be thought of as the lipos discharge capability. If you have a 20C 5000mah its discharge capability is 20 x 5000/1000 = 100amps. The same capacity but 30C would have 30 x 5 = 150amps. So, there is a diff. It is indirectky influenced by the mah or capacity as you can see with how the discharge capability is calculated. A 40C 3400mah would have 136amps and have more discharge capability than a 20C 5000mah which would only be 100amps.
Where does it make a diff? It depends on the setuo you;re running and how many amps it needs. If you're running a heavy rc like a Flux, the higher C rating does make a diff you can see. If you're running a 5lb onroad car, it is prob not going to make a visible diff. They other way the C rating shows up is in lipo temp - if your batt is having to supply 80-90 of its C capability a lot of the time, it will run hot which is not what you want for long life. If you size teh C rating so the setup is using a lower percentage of its capability, it will run cooler and have a longer life.
There are some good links here, read teh one from the Heli site, it will help with understanding - Lipo for newbies
Excellent Information. I understand what you are explaining and teaching. I am a very fast learner. So what I want to ask you is......
I run a RC10 B4 with LRP SXX and a 10.5 orion
I have 2 orion Platnuim Batts 4800 mah 20C batteries that are used and
I have 2 Teak tekin 3400 Mah 23C Batteries that are new
Which would be better for the car? I now only run a SMC batt 5200 Mah 24C at the moment. I am trying to use 2 of the same batteries so I dont throw off the weight distro when changing batts. =)
The Orions would appear to have the higher discharge, 78amps vs 96amps. But the SMCs are even higher at 125amps.
The one variable in this thats not been mentioned is the C ratings. There's no industry standard for determining th Crating, a little like HP rating for nitro engines. One company's 30C may be another companys 25C if they are more conservative. Orion is made using Kokam cells and they are one of the best lipo cells out there. SMC tends to be conservative based on data I've seen and read. They're great lipos as well. All this is based strictly on discharge capacity.
I'll leave it to our resident racers to weigh in on what will be enough for your setup.
Last edited by Duster_360; 10-22-2009 at 03:01 PM.
One company's 30C may be another companys 25C if they are more conservative.
I'll leave it to our resident racers to weigh in on what will be enough for your setup.
Can you be more elaborate on that. I dont understand or can figure out how one teams C rating can be anothers. Are you saying the cells are shit and not as good? Or the quality of the pack?
Also how many cycles can you get out a battery? Or how many cycles till you notice the batteries not performing to its standards?? Just some info Id like to find out before I go out n spend some dough on 2 good batts to run..
No, not saying that at all. There is no RC industry accepted standard for establishing a lipos C Rating. Period, its a fact. Its basically up to the manufacturer to decide what his lipo C ratings are going to be. Some use rigorous testing, some use less rigorous testing. This is what I meant by company A's 30C may be no better than company B's 25C rating. This is why performance based feedback is helpful in deciding what to purchase.
There are quality differences in lipo cells. Some cells hold higher voltage at a given amp dioscharge than others. Some of this is quality (cost) related and some of it is not. Some of the extra cost is for assembly - premium lipos are made with matched cells - they are matched not only for voltage, but internal resistance as well. Some manufacturers do nothing but wire cells together and package. I run some lipos from Neuenergy - I can discharge 80% of the pack capacity and when I put it on the charger, the cells are almost identical, usually not more than .002v (2mv) out of balance. Lesser quality or unmatched cells, I've seen guys say they were 90mv difference in voltage. Cell imbalance during discharging can cause probs and you can damage a cell at the extreme.
I've been using some of mine for 3yrs. You should be able to get hundreds of cycles if treated with care and maintained (balanced). Lipos are getting better and better as far as life is concerned. My first ones started fading after 100cycles.
So how does your esc join into the equation? I know your esc is rated at an amperage right? So do you get a c rating that doesn't exceed your rating on the esc? Say in your equation above with a 20 c at 100 amp, does your esc have to be rated at 100 amp? Also does the motor matter or does the esc control the amperage?
My understanding is it's the motor that sets demand based on speed, load and other factors. Its the esc's job to supply. You match the esc to the motor.
I've messed around with an onboard data recorder on my Slash that I run with 2S 5000mah 25C IP lipos with a MM/5700 Castle combo. There is a big diff in what the lipo can generate based on its C rating and what the recorder shows the system is using. A typical bash session in my backyard, recorder over a 8 min part of the run showed an average amp draw of 18amps. The highest amp draw was a 114amp spike and there were several other spikes that were above 100amps. There were plenty od draws in the 40-80amp range as well. But with coasting, or running at constant speed, tha average is pretty low.
I prob could do with a lesser lipo since the burst rating could prob cover the amp spikes, but I wouldn't want to push a lipo harder and have it run hot. This lipo comes out after 25min just barely warm. Thats the setup I want to run - one that keeps everything cool.
one small tip ive been given is even if battery A is 5000mah and 40C, battery B could be 5400mah and 25C. it may not theoretically give more current, though the larger capacity will keep the voltage at its maximum longer, giving you that "punch" longer.. more V = more torque! (i believe)
No, not saying that at all. There is no RC industry accepted standard for establishing a lipos C Rating. Period, its a fact. Its basically up to the manufacturer to decide what his lipo C ratings are going to be. Some use rigorous testing, some use less rigorous testing. This is what I meant by company A's 30C may be no better than company B's 25C rating. This is why performance based feedback is helpful in deciding what to purchase.
There are quality differences in lipo cells. Some cells hold higher voltage at a given amp dioscharge than others. Some of this is quality (cost) related and some of it is not. Some of the extra cost is for assembly - premium lipos are made with matched cells - they are matched not only for voltage, but internal resistance as well. Some manufacturers do nothing but wire cells together and package. I run some lipos from Neuenergy - I can discharge 80% of the pack capacity and when I put it on the charger, the cells are almost identical, usually not more than .002v (2mv) out of balance. Lesser quality or unmatched cells, I've seen guys say they were 90mv difference in voltage. Cell imbalance during discharging can cause probs and you can damage a cell at the extreme.
I've been using some of mine for 3yrs. You should be able to get hundreds of cycles if treated with care and maintained (balanced). Lipos are getting better and better as far as life is concerned. My first ones started fading after 100cycles.
I have 2 brand new team tekin 3400Mah 23c Batts Should I use these or get rid of them and gett sumthing higher in voltage for racing??? I dont know how to balance the orion batterys with my hyperion duo, also I have a smc so how do i balance that with my charger?? I am new to this Lipo stuff and it would help me out.
Now also can you link me to a shitty battery, and then link me to a excellent battery? And what I should buy and what I should not buy. this will help me out alot.
I use a Lrp SXX w/ the orion motors. So I dont think I have an issue with them. I do wiht batteries. I havent tryed the tekins yet. So IDk about those. Any1 else use them?
Just my opinion, but seeing an oddball C rating (not an even number like 20,25 or 40) makes me guess the company has been conservative, they prob could have used a little lower voltage and said it was 25C, butthey didn't. That gives me a good feeling about them. I only know Reedy by rep and its a good one from everything I've seen and read. I wouldn't hesitate to use them. Again, I'm not familiar with your setup, but seems to me the Reedys should do a fine job.
These are hard case and need a separate harness to balance with. This should work with your DUO -
If you look at the diagram, believe you'll see how it works. You'll need two for the DUO if you want to balance charge both at once. I use this harness for my IP lipos which are hard cased.
Crappy lipo - go to eBay ans search in 'toys and hobbies' category for lipo. Take teh cheapest one as a crappy lipo cause it prob is. The Reedys or Orions are premimum lipos that are hard cased, Hyperions, Neuenergy, PolyQuest are premium soft cased lipos. Look at all these here -
Just my opinion, but seeing an oddball C rating (not an even number like 20,25 or 40) makes me guess the company has been conservative, they prob could have used a little lower voltage and said it was 25C, butthey didn't. That gives me a good feeling about them. I only know Reedy by rep and its a good one from everything I've seen and read. I wouldn't hesitate to use them. Again, I'm not familiar with your setup, but seems to me the Reedys should do a fine job.
These are hard case and need a separate harness to balance with. This should work with your DUO -
If you look at the diagram, believe you'll see how it works. You'll need two for the DUO if you want to balance charge both at once. I use this harness for my IP lipos which are hard cased.
Crappy lipo - go to eBay ans search in 'toys and hobbies' category for lipo. Take teh cheapest one as a crappy lipo cause it prob is. The Reedys or Orions are premimum lipos that are hard cased, Hyperions, Neuenergy, PolyQuest are premium soft cased lipos. Look at all these here -
I have 2 brand new team tekin 3400Mah 23c Batts Should I use these or get rid of them and gett sumthing higher in voltage for racing??? I dont know how to balance the orion batterys with my hyperion duo, also I have a smc so how do i balance that with my charger?? I am new to this Lipo stuff and it would help me out.
?????
I have 2 brand new team tekin 3400Mah 23c Batts Should I use these or get rid of them and gett sumthing higher in voltage for racing??? I dont know how to balance the orion batterys with my hyperion duo, also I have a smc so how do i balance that with my charger?? I am new to this Lipo stuff and it would help me out.
?????
This is what you need to balance charge your Orion/Trakpower/Tekin packs using your Hyperion charger..
I don't have any SMC packs so I don't know much about them
thank you I already know about that adapter.
I am talking about Lipo Batteries.... What 2 should I buy for Racing. I have plenty of used batteries. I want 2 for just racing. So let me know what you guys think thanks.
Lipo Batteries
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