Battery Load Test Comparisons

[Collin41]

This post is to share my results from testing a number of batteries under high amp loads. I question whether buying a Thunder Power is worth it's cost if an alternative brand consistantly performs better and is half the price. I wanted to know if 60 and 65C ratings were just hype. I've considered different ways to test batteries and evaluated what to look for to determine if a battery is actually putting out "60C" for example. I could find no definition for measuring "C" rating. Battery manufacturers never, ever, ever talk about it so there's probably a lot of hype going on.

We decided the only way to get some answers was to put a few batteries under a serious high load and see what squeezes out. Regardless of what the manufacturers imply with their high C ratings, even a gold plated battery pushing 200 amps through 10 gauge wires will melt the solder off the junctions. A case in point is the first test of Thunder Power's flagship 5000mah, 65C, 6S $250 Lipos showed that the 4mm bulleted split pack link connector melt off their wires at the equivalent of 32C.

To be fair TP's have the reputation of running strong long after the cheapies will turn to junk. However I take that on faith because I've never put 100 cycles on any one battery so I have no other way to tell. But what I do think is if I reeeeaallly load up a battery a few times it will start to show it's true colors. It will run hotter then the higher quality cells, get puffy when maxed out, etc.

Lipo break in is another issue. I've seen that the better batteries tend to get stronger as more cycles are run but have seen little change with the cheapies. I made sure all the batteries had a minimum of 6 light duty break in cycles on them before testing.

Voltage available under high load was another area of question. I've seen ESC's cut out when the throttle is opened past 75% because a crap battery couldn't keep up with a motors current demand so the ESC shuts down on low voltage. So what's a "respectable" percentage of voltage a battery will hold under load? Does one hold 5% voltage reserve at WOT conditions while another will hold 25%?

To get a start at some answers I built a box that puts a constant resistance across the batteries terminals. Using OHM's law and 6S as my standard I calculated what the nominal current should be and provided a number of different "taps" or resistances I could plug into. The resisters are large spiral types that act like a powerful heater so 1200 SCFM of air is blown over them during testing. While the batteries are under load the voltage, current and temperature are recorded. A common lipo tester is plugged into the balance taps so the actual percentage of voltage remaining is displayed.

There are the caveats: This is called "resistive" loading. When we run our motors we are putting them under an "inductive" load which is a different kind of load. A resistive load will tell you alot but there will be difference in the results. Also differences whether the load is pulsed or sustained, etc. Therefore the second half of this posting will be with an inductive load producing tester.

[MasteroFlego]

Sounds interesting. SMC has also done testing, if you want to check that out

Sent from my Nexus 5 using Tapatalk

[Hydrocarbon92]

So are you checking voltage drop with an ammeter or just how hot certain things get?

I found someone who made a spreadsheet where you input measured mOhms from your charger and battery capacity to get a fairly accurate max amp value. IIRC 3 & below is for very high amps, 3-5 for medium amp loads, and 5+ is for low powered brushed apps. IIRC my Gens Aces are lower 3's, SMC's in the 4's, and Turnigys in the 3.5-4.5 range depending on the size. In my boat I loose a few MPH switching from the Aces to the SMC, but 2x Turnigy in parallel are about the same (when trimmed for the extra weight). It's using a fairly hefty 3674 2250kv motor, or a little bigger than a Castle 1415.

[THX_138]

Originally Posted by Collin41

This post is to share my results from testing a number of batteries under high amp loads. I question whether buying a Thunder Power is worth it's cost if an alternative brand consistantly performs better and is half the price. I wanted to know if 60 and 65C ratings were just hype. I've considered different ways to test batteries and evaluated what to look for to determine if a battery is actually putting out "60C" for example. I could find no definition for measuring "C" rating. Battery manufacturers never, ever, ever talk about it so there's probably a lot of hype going on.

We decided the only way to get some answers was to put a few batteries under a serious high load and see what squeezes out. Regardless of what the manufacturers imply with their high C ratings, even a gold plated battery pushing 200 amps through 10 gauge wires will melt the solder off the junctions. A case in point is the first test of Thunder Power's flagship 5000mah, 65C, 6S $250 Lipos showed that the 4mm bulleted split pack link connector melt off their wires at the equivalent of 32C.

To be fair TP's have the reputation of running strong long after the cheapies will turn to junk. However I take that on faith because I've never put 100 cycles on any one battery so I have no other way to tell. But what I do think is if I reeeeaallly load up a battery a few times it will start to show it's true colors. It will run hotter then the higher quality cells, get puffy when maxed out, etc.

Lipo break in is another issue. I've seen that the better batteries tend to get stronger as more cycles are run but have seen little change with the cheapies. I made sure all the batteries had a minimum of 6 light duty break in cycles on them before testing.

Voltage available under high load was another area of question. I've seen ESC's cut out when the throttle is opened past 75% because a crap battery couldn't keep up with a motors current demand so the ESC shuts down on low voltage. So what's a "respectable" percentage of voltage a battery will hold under load? Does one hold 5% voltage reserve at WOT conditions while another will hold 25%?

To get a start at some answers I built a box that puts a constant resistance across the batteries terminals. Using OHM's law and 6S as my standard I calculated what the nominal current should be and provided a number of different "taps" or resistances I could plug into. The resisters are large spiral types that act like a powerful heater so 1200 SCFM of air is blown over them during testing. While the batteries are under load the voltage, current and temperature are recorded. A common lipo tester is plugged into the balance taps so the actual percentage of voltage remaining is displayed.

There are the caveats: This is called "resistive" loading. When we run our motors we are putting them under an "inductive" load which is a different kind of load. A resistive load will tell you alot but there will be difference in the results. Also differences whether the load is pulsed or sustained, etc. Therefore the second half of this posting will be with an inductive load producing tester.

If you want to come here and learn and or share your information or work, that’s perfectly fine and happy to have you involved.....


But if you’re simply here to try and make yourself look educated and part of the hobby..... you might want to be sure you full well know who’s work and writings that you are plagiarizing first and especially it’s not someone a MOD knows personally.

The above post you made isn’t yours and was originally posted back SIX years ago in 2012 by a friend in Washington State.

https://www.rcgroups.com/forums/show...ons&perpage=30

I’m going to check other posts on here by you, if I find others (good information or not) and if they are also situations of plagiarism, they will either be deleted or moved to chit chat.

RCCrawler is a great place to learn and share, but please be WHO YOU ARE, and not pretend to be a genius by stealing others writings. We all started in the hobby with zero knowledge, it’s perfectly ok to not know and ask instead of doing what you’re doing.

Don’t get yourself banned for plagiarizing others stuff.

[Duuuuuuuude]

Originally Posted by THX_138

The above post you made isn’t yours and was originally posted back SIX years ago in 2012 by a friend in Washington State.

Well know I'm kinda curious how this thread would have played out had nobody caught that.

[Duuuuuuuude]

I just went through and deleted 6 or 7 more posts that were plagiarized from other forums.

[THX_138]

Originally Posted by Duuuuuuuude

Well know I'm kinda curious how this thread would have played out had nobody caught that.

Originally Posted by Duuuuuuuude

I just went through and deleted 6 or 7 more posts that were plagiarized from other forums.

There was a few, like this thread from him, that although plagiarism I moved to chit chat simply because of your exact above comment.... interested to see how they played out because of the good info or questions he stole and reposted.

Not sure if it was all done to make his post count build... or simply because he was attempting to sound smart.
I don’t have the best memory anymore, but not many people use “caveats” and that’s what triggered my memory.

Not too mention one post he’s asking simple common sense two sentence questions.... then suddenly pumping out theoretical novels... kinda didn’t add up.

[durok]

What kills me is that he says he's in Bali, but he's posted a crawler vid from Montana. Initially I was responding to him as if he was confused about the site's purpose because he was perhaps using a translation program and misunderstanding... But now I'm just friggin' annoyed.

I posted a fairly aggressive response to one of his most recent aviation-related posts and then deleted it because I calmed down (right after I reported the post) - but then I just now found the post was moved to Chit-Chat WITH my response still included - and I watched it disappear earlier!

Funny thing is, now that I've read this thread - I'm happy with leaving my response in there......

I had noticed him cutting-and-pasting directly from other sites about various chargers and reported those... as well.

Had no idea that he's being THIS blatant, though.

Far out, man........

(funny coincidence - when I was a little elementary-school kid, my dad was an advisor to the Indonesian Army for a couple years - as an officer in the U.S. Army, Corps of Engineers... We lived in Jakarta, the capital city - and did a little vacation in Bali in the mid-'70s before it became a really fancy world-wide tourist spot. So, I went to all the trouble of writing some stuff in Indonesian in a response post a while back to be nice... D'Oh!)

[Elmo]

On RCShortcourse we have a few different people from GensAce/Tattu posting advertisements thinly veiled as "questions" and also posting things that are copied and pasted from other sites. Originally I would PM the person and ask them to remove the post but nothing is done about it so now I call them out on it publicly. I've noticed that most of "collin41's" posts are centered around GensAce products and that's what caught my attention.