Chris_The_Battery_Man
I wanna be Dave
So, as of late, we have noticed that ALOT of manufacturers lipos are not holding up to their ratings. It kind of depresses me to see all the lieing. No matter if it is a well known brand, cheap ebay pack, or something from hobby king, seems like alot of todays lipos are severely over rated.
Lately I have seen ratings at 50C, 60C, and even "True 150C". Ratings we have seen first hand in most cases, that are FAR from the truth.
What made me want to post is seeing a well known brand advertise a 6500mah pack @ 150C. This would mean by industry standard, that the pack should be able to take a 975amp load, still retain about 3.4-3.7 volts per cell, AND get 6500mah of runtime.
I have problems with this...
A: Solder begins to un-solder it self @ about 200 amps.
B: No one else in the industry, even claims more than 100amps BURST. And that is with their over rated ratings.
C: This brand shows no proof of this rating.
D: We tested this brand's packs. Their pack didn't even hardly qualify as a 10C cell, but it was rated as a 50C. So how is it they cant get a 50C right, but just straight to 150C? 10C is only 20% of it's ratings. So with that, my educated guess is that this pack is probably only a 30C, which is 20% of 150.
I would love for this brand to prove this, or send a pack to me to test. Because if this IS true... I want. That is some massive power.
The above mentioned brand, does not believe in C ratings because they say that no one will ever use the packs at those loads(guess they haven't raced electric boats:roll
which is 99% true. But this is the only way to test everything across the board the same way under the same conditions. That is no different than saying a Dyno is pointless to rate horse power, because someone will never use all the horse power.
Personally I feel there should be regulations with these ratings for all battery manufacturers. This is simply lieing. There is no other word for it. You are paying for something you will not get. It is wrong.
I will let you guys decide what's fair. I am not here to pick on anyone. Perhaps the above brand has no way of testing, and are taking the factories word for it. I don't know. Either way, lieing is lieing.
So just so those that care, and read this post understand, I am going to briefly explain the C ratings.
C rating:
C is a rating at which your battery can be discharged safely. The higher C the more amps(higher load) the pack can handle.
Example:
1000mah(1 amp hour) pack rated at 20C = 20amps constant. 1 amp hour x 20 = 20 amps.
1500mah(1.5 amp hour) pack rated at 20C = 30 amps constant. 1.5 amp hour x 20 = 30 amps.
How this is tested and what to expect.
The way of testing is pretty simple. You just apply a constant load to a lose lipo cell, and record it's voltage, and how long it runs(runtime/mah). The pack should get at or above 3.4v, at it's constant C rating, and get to within 95% of it's rated mah. Below is a good graph as an example. You can see, as the load(amps) increase, the voltage drops. That is normal. But the capacity(mah) is always really close.
Let me know if you guys have any questions. I would be glad to answer them"thumbsup"
Lately I have seen ratings at 50C, 60C, and even "True 150C". Ratings we have seen first hand in most cases, that are FAR from the truth.
What made me want to post is seeing a well known brand advertise a 6500mah pack @ 150C. This would mean by industry standard, that the pack should be able to take a 975amp load, still retain about 3.4-3.7 volts per cell, AND get 6500mah of runtime.
I have problems with this...
A: Solder begins to un-solder it self @ about 200 amps.
B: No one else in the industry, even claims more than 100amps BURST. And that is with their over rated ratings.
C: This brand shows no proof of this rating.
D: We tested this brand's packs. Their pack didn't even hardly qualify as a 10C cell, but it was rated as a 50C. So how is it they cant get a 50C right, but just straight to 150C? 10C is only 20% of it's ratings. So with that, my educated guess is that this pack is probably only a 30C, which is 20% of 150.
I would love for this brand to prove this, or send a pack to me to test. Because if this IS true... I want. That is some massive power.
The above mentioned brand, does not believe in C ratings because they say that no one will ever use the packs at those loads(guess they haven't raced electric boats:roll
which is 99% true. But this is the only way to test everything across the board the same way under the same conditions. That is no different than saying a Dyno is pointless to rate horse power, because someone will never use all the horse power.Personally I feel there should be regulations with these ratings for all battery manufacturers. This is simply lieing. There is no other word for it. You are paying for something you will not get. It is wrong.
I will let you guys decide what's fair. I am not here to pick on anyone. Perhaps the above brand has no way of testing, and are taking the factories word for it. I don't know. Either way, lieing is lieing.
So just so those that care, and read this post understand, I am going to briefly explain the C ratings.
C rating:
C is a rating at which your battery can be discharged safely. The higher C the more amps(higher load) the pack can handle.
Example:
1000mah(1 amp hour) pack rated at 20C = 20amps constant. 1 amp hour x 20 = 20 amps.
1500mah(1.5 amp hour) pack rated at 20C = 30 amps constant. 1.5 amp hour x 20 = 30 amps.
How this is tested and what to expect.
The way of testing is pretty simple. You just apply a constant load to a lose lipo cell, and record it's voltage, and how long it runs(runtime/mah). The pack should get at or above 3.4v, at it's constant C rating, and get to within 95% of it's rated mah. Below is a good graph as an example. You can see, as the load(amps) increase, the voltage drops. That is normal. But the capacity(mah) is always really close.
Let me know if you guys have any questions. I would be glad to answer them"thumbsup"
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