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LIPO problems noob in training

Old 09-12-2010, 11:38 AM
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inteva6184
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Default LIPO problems noob in training



Hey guys Ihave searched and theirs a ton of info on lipos but Iam not finding anything specific to me. So first heres my setup. Its a ofna hyper 8 running a 80a esc and a 2370 7xl. My spur is a 46t and my pinion is 20t a little big Iknow but that setup doesnt get hot at all.The battery that Iam talking aboutis a turnigy 4s 30c 4.5. So here is my issue I went out for a bashing yesterday everything was going great did a bunch of full throttle runs no issue until we saw that huge quarter mile oval track. The ofna did great was full throttle around the track a few times I would say Imight have been full throttle for 30 seconds at a time. I then took it out for a little more abuse I drove it back to me bent over to pick it up and the hardshell popped apart one of the cells swelled up. This battery has only been charged about 10 times and was balanced each time. I never drain it to much so I dont know whats going on. My theory is Iam working the battery to hard causing this to happen and Imight need a 40c or bigger. What do you guys think?

Old 09-12-2010, 11:47 AM
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Default RE: LIPO problems noob in training

It sounds like you were overgeared.
Old 09-12-2010, 12:26 PM
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Default RE: LIPO problems noob in training

You're theory is correct, you might need a 40C or bigger. It is also possible that one or more cells was overdischarged.
Old 09-12-2010, 03:42 PM
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Default RE: LIPO problems noob in training

If not a 4500 mah 40c, then get a 5000 or higher mah battery rated at 30+ C (150 amp discharge) or even 5000 mah at 40C (200 amp discharge rate) if that is not too much more and you will have a much better safety margin.

And next time out, just make it a habit to check up on the battery (even if the motor/ESC are not hot) especially when dealing with lipo, every few minutes or passes, until you know it works reliably. Keep it below 120*F and you will have a better working battery. Also, balance them (assuming you already have that take care of) so one cell doesn't dump before the others and puff up.
Old 09-12-2010, 03:53 PM
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Default RE: LIPO problems noob in training

This is what I have been afraid of... a new-comer seeking LiPo related questions on THIS forum. **SIGH, SUPERSIGH**

Inteva6184, I have a link that will keep you BUSYFORWEEKS on ALL Lipo related questions consisting of personal experiances, and TRUEFACTUALINFORMATION!!! YOU WILLNOTFINDITHEREFROM SEVERALOFTHE"EXPERTS" on this forum, SOBEWARE!! . There are a few SERIOUSLY STUBBORNLIPOFANBOYDIEHARDSONTHISFORUM that will tell you that LiPo is safer than a padded room, Isware, its true.

These such folks here are IDIOTSand are PURELY MISLEADINGTHE NEWBIES here just because they are DIE-HARDFANBOYS of LiPos.


Here is your link:

http://www.rcgroups.com/forums/showthread.php?t=209187
Old 09-12-2010, 05:10 PM
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Default RE: LIPO problems noob in training

ORIGINAL: VXL_BASH

This is what I have been afraid of... a new-comer seeking LiPo related questions on THIS forum. **SIGH, SUPER SIGH**

Inteva6184, I have a link that will keep you BUSY FOR WEEKS on ALL Lipo related questions consisting of personal experiances, and TRUE FACTUAL INFORMATION!!! YOU WILL NOT FIND IT HERE FROM SEVERAL OF THE ''EXPERTS'' on this forum, SO BEWARE!! . There are a few SERIOUSLY STUBBORN LIPO FANBOY DIEHARDS ON THIS FORUM that will tell you that LiPo is safer than a padded room, I sware, its true.

These such folks here are IDIOTS and are PURELY MISLEADING THE NEWBIES here just because they are DIE-HARD FANBOYS of LiPos.


Here is your link:

http://www.rcgroups.com/forums/showthread.php?t=209187
how does that link help him at ALL with his current issue?

Back on to the question I'm going to guess your batteries were way out of balance. Your battery should have been fine seeing its maximum output would be 120A, and seeing the ESC is rated 80A I would think the ESC would have blown if you pulled over 120A through it. But that is just my guess.
Old 09-12-2010, 05:12 PM
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Default RE: LIPO problems noob in training

ORIGINAL: VXL_BASH

This is what I have been afraid of... a new-comer seeking LiPo related questions on THIS forum. **SIGH, SUPER SIGH**

Inteva6184, I have a link that will keep you BUSY FOR WEEKS on ALL Lipo related questions consisting of personal experiances, and TRUE FACTUAL INFORMATION!!! YOU WILL NOT FIND IT HERE FROM SEVERAL OF THE ''EXPERTS'' on this forum, SO BEWARE!! . There are a few SERIOUSLY STUBBORN LIPO FANBOY DIEHARDS ON THIS FORUM that will tell you that LiPo is safer than a padded room, I sware, its true.

These such folks here are IDIOTS and are PURELY MISLEADING THE NEWBIES here just because they are DIE-HARD FANBOYS of LiPos.


Here is your link:

http://www.rcgroups.com/forums/showthread.php?t=209187
That does NOT help the OP with his current problem. You are simply copy and pasting your BS argument in every thread in which you participate.

Any ANY over-drawn battery, which would be caused by too tall of a gear, will puff. Amperage is the enemy of electrical components. Just because YOU don't understand the basic principles of electricity does NOT mean HJJFFFAA or ANYBODY ELSE is out to misinform people.

NOT to mention you are spamming a non-RCU forum on RCU.

Call off your witch hunt.
Old 09-12-2010, 05:19 PM
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Default RE: LIPO problems noob in training

ORIGINAL: VXL_BASH

This is what I have been afraid of... a new-comer seeking LiPo related questions on THIS forum. **SIGH, SUPER SIGH**

Inteva6184, I have a link that will keep you BUSY FOR WEEKS on ALL Lipo related questions consisting of personal experiances, and TRUE FACTUAL INFORMATION!!! YOU WILL NOT FIND IT HERE FROM SEVERAL OF THE ''EXPERTS'' on this forum, SO BEWARE!! . There are a few SERIOUSLY STUBBORN LIPO FANBOY DIEHARDS ON THIS FORUM that will tell you that LiPo is safer than a padded room, I sware, its true.

These such folks here are IDIOTS and are PURELY MISLEADING THE NEWBIES here just because they are DIE-HARD FANBOYS of LiPos.


Here is your link:

http://www.rcgroups.com/forums/showthread.php?t=209187
Yea, beware of people on this forum that have been running lipo's, and rc's in general, for years they know nothing about them. Forums are to help people with rc issues of all types. Everyone was a "noob" at some point. No one knows everything but there are a lot of very knowledgeable people on these forums that can help people who are getting started. I love your signature, it must mean that since you only have 46 posts you must know everything.
Old 09-12-2010, 06:51 PM
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inteva6184
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Default RE: LIPO problems noob in training

Wow guys I didnt mean to start a war haha. Thanks for all the info though.  As far as them being balanced they are.  I always balance them and I just checked all my other lipos and they are all spot on so I think my charger is doing a good job.  By the way its a venom pro charger I know its not the best but its worked pretty good for me so far. 

So guys seems like we are thinking its a draw issue so now I have new issues.  One is I am crazy and just bought 4 zippy 4000mah 40c 4s batteries before I saw slo v's suggestion.  I know they arent high end batteries but sadly I am poor right now so its what I could afford.  So here is my problem I am loving the top end my car has now I am guessing 50-60 judging by those speed calculators and how fast it passed my friends car that goes 35-40.  It also is extremely controllable down low so all around I am happy with it.  So will these new batteries handle that kind of draw or am I going to have to gear it down a little.  Thanks again for all the help.   
Old 09-12-2010, 07:03 PM
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Default RE: LIPO problems noob in training

This diag question may decide whether the trouble was a over current problem or an under voltage problem. I'd hate to see you but the best batts you can get (adequately sized) and have the same exact trouble.

How long was the runs? (in minutes)
Old 09-12-2010, 07:06 PM
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inteva6184
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Default RE: LIPO problems noob in training

Well my guess is about 20 minutes.  The thing is it didnt slow at all and I thought I programmed it to cut off a 3.4 volts or so I will have to check what its set at.
Old 09-12-2010, 07:13 PM
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Default RE: LIPO problems noob in training

lol his post got deleted, but it is still their in quotes
ORIGINAL: VXL_BASH

This is what I have been afraid of... a new-comer seeking LiPo related questions on THIS forum. **SIGH, SUPERSIGH**

Inteva6184, I have a link that will keep you BUSYFORWEEKS on ALL Lipo related questions consisting of personal experiances, and TRUEFACTUALINFORMATION!!! YOU WILLNOTFINDITHEREFROM SEVERALOFTHE''EXPERTS'' on this forum, SOBEWARE!! . There are a few SERIOUSLY STUBBORNLIPOFANBOYDIEHARDSONTHISFORUM that will tell you that LiPo is safer than a padded room, Isware, its true.

These such folks here are IDIOTSand are PURELY MISLEADINGTHE NEWBIES here just because they are DIE-HARDFANBOYS of LiPos.


Here is your link:

http://www.rcgroups.com/forums/showthread.php?t=209187
Old 09-12-2010, 07:17 PM
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Default RE: LIPO problems noob in training

If you've already bought those other lipos, that's fine, they are more capable than your puffed one, however PLEASE do gear down a couple of teeth, it won't kill your top speed but it may just save your battery if for some funky reason your system is over drawing the lipos and give you just that more better runtimes, and cooler running.

As for the genius bashing everyone on this forum who gives lipo advice. granted there are newbies who try to help other newbies with wrong information, but for the most part, on this particular thread everyone's suggestions have been valid for the topic and question. There's always 100 reasons for something to go wrong, you just eliminate the variables and try to find the cause as best as possible. We're not all lipo fan boys, I wouldn't mind using Nimh if they didn't crap out on me every 2 months just sitting or being used and overheating so easily on brushed motors alone, from cheap to $50 packs.
Old 09-12-2010, 07:42 PM
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inteva6184
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Default RE: LIPO problems noob in training

Thanks for the suggestion. Its just ashame with a 16t it only topped out at 40 mph and it runs so much better with a 20t I guess I just gotta deal with it being slower or pay to play   Oh and I forgot I am actually on a 48t spur not that that matters since I trashed batteries anyway.
Old 09-12-2010, 08:01 PM
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Default RE: LIPO problems noob in training

Top speed runs (especially long ones) are great for trashing equipment. and lots of fun.

If we do a little loose math we can conclude that a 20 minute run is an average of 3C and even if we consider those 40C batts to actually only be 20C then we can assume that they were not discharged "too fast" , but rather "too low"

That's my best guess with the available info.
Old 09-12-2010, 08:19 PM
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inteva6184
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Default RE: LIPO problems noob in training

well guys I just checked the remaining good cells 3.63 3.66 and 3.34 so the one cell was much lower than the others so my guess is that the 4th could have been even lower.  So my question is why exactly do they discharge at different rates?
Old 09-12-2010, 08:19 PM
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Default RE: LIPO problems noob in training

i've had 3s batteries puff on my slash 4x4 as well, and the only time that happened was from running in an open pit with lots of full throttle runs. i've never had them puff on an actual track, or just bashing in a smaller space.
Old 09-12-2010, 10:31 PM
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Default RE: LIPO problems noob in training


ORIGINAL: inteva6184

well guys I just checked the remaining good cells 3.63 3.66 and 3.34 so the one cell was much lower than the others so my guess is that the 4th could have been even lower. So my question is why exactly do they discharge at different rates?
They don't. Cells in series must discharge all at the same rate. (this gets many riled up)

Old 09-12-2010, 10:43 PM
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Default RE: LIPO problems noob in training

the same current is going through all the cells, but not all cells are made equal.
Old 09-12-2010, 11:10 PM
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Default RE: LIPO problems noob in training

That is a good reason to have a seperate balancer.....
Old 09-13-2010, 02:32 AM
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Default RE: LIPO problems noob in training

Did you check your motor and esc temps. at all?
I'm thinking that if you were using too big a pinion your motor would overheat also.

Also check that your drive-train is running smoothly. I once had a battery overheat because a busted bearing was causing the motor to overwork.
Old 09-13-2010, 06:48 AM
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Default RE: LIPO problems noob in training


ORIGINAL: Brainanator

the same current is going through all the cells, but not all cells are made equal.
That's correct, and is the reason that we get an imbalance when discharged (unless the cells are capacity matched)

Old 09-13-2010, 01:24 PM
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Default RE: LIPO problems noob in training


Braininator has it... Cells under load can vary and lipos are tempramental.
The problem with using temp as a guide is it shows what you've already done (history), so it doesn't help prevent a problem.

Let's look at your hardware...
80A ESC. Is that peak or continuous? If continuous, you should set up for 80% of the ESC capacity. If you gear for 80 amps, you should buy a battery and ESC (and motor) that will provide 100A continuous. This will provide a 25% cushion for safety.

4.5A 30C battery. This 'should' provide 135A, but most batteries show 'peak' rating (for advertising reasons), not continuous. Depending on manufacturer, battery peak rating may be 10 to 30 seconds at that load. If the battery is good for 135 amps peak, it's generally good for 1/2 that continuous, or 67.5A. Using the 80% rate as a cushion, that battery should be run at a max of 54 amps continuous[X(]. Think continuous, not peak!

It should be noted that the brushless motor and esc are 'seeing' the max amp load continuously, the esc is simply switching that load on and off rapidly according to throttle position. For example, if the load is 80A and throttle position is half (50%), the esc is switching 80A on and off 50% of the time. Don't think that just because you're running the throttle at half that your equipment is loafing. Check out the Astro, Castle and Red Scholefield websites where this is explained.

The comments about buying the best equipment are true, but even that is no guarantee sometimes. Battery manufacturers are especially notorious for 'fudging' their numbers to make their packs appear better then their competitors.

Has anyone looked at A123 cells? They take abuse without 'venting with flame' as Lipos do.

Have fun!
Old 09-13-2010, 03:03 PM
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Default RE: LIPO problems noob in training

That link has more info than any of you dipsh*ts will EVER be able to give him/her. If any of you trash talkers ever come to Cali, (4o minutes south of LA) I would be happy to film us racing (I wont even race my T4) and then put the video on here for all to see.Bunch of trash talkers who live on here every second of the day. You all cant possibly be doing anything but getting calusis on your Azz's.Come to Cali and we'll film it, I dare you.
Old 09-13-2010, 05:39 PM
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Default RE: LIPO problems noob in training

thanks for the info guys.  As far as the motors and esc go I havent checked temps yet but I did the gangster hand check haha and it didnt leave any skin and I could actually hold it so I assume thats cool enough.  The esc is rated 80a continuous.  Thanks again

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