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Old 06-30-2011, 04:28 AM   #5461
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Hi guys

I have been doing some testing on some lipos of many brands not to degrade them but to see how they can come back from low voltage readings .

I have found some info that can help most of you when you do have a low voltage signal from your charger .

I found that most batteries can be brought back by using a lower charging input example

for 7.4V 2s when showing low voltage charge the battery at 1s without the balance lead attached for 3-5 minutes then plug the balance lead in and switch to 2s .

The same happened with 3s with low voltage signal charge at 2s without the balance lead and then swap back to 2s after 3-5 minutes with balance lead plugged in .

same with 4s charge at 3s for 3-5minutes without the balance lead and so on .

I have heard many people use nimh to jump them cells for 5-10 seconds but thats a very dangerous way of doing it .The way i have been testing is the safe way .

It might not work with cheaper cells but you will never know until you try .

Most of the higher end packs worked really well .

now back to esc's

thank you for your time

regards Angelo

From all the packs i tested they all came back to normal voltage levels .
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Old 06-30-2011, 04:33 AM   #5462
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What gearing are you running. Is the motor and or the esc really hot? Could be thermaling out.
yes you are correct thermal could be another reason as the 5.5T is the lowest you can run on the 60 amp esc so gearing and timing is very important .If your timing is the extreme the esc could be shutting down over heat .
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Old 06-30-2011, 05:17 AM   #5463
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going to get jumped on as usual but here goes
worse thing to do is constantly balance charge lipo`s every time
i used to balance charge every time years ago, but was told by a guy in the battery industry the worst thing to do is balance them to much.
since then i only balance charge if the cells are more than .03 of a volt out
which is very very rare, i have had a couple packs for 3-4 years still going strong that have never been balanced.
mind you i check voltage every charge and very rarely run till low voltage kicks in and i take care of by packs.
lipo quality has come a long way in the last 4-5 years and are not as temperamental or fragile as they once were.
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Old 06-30-2011, 05:59 AM   #5464
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Originally Posted by ozzy-crawl View Post
going to get jumped on as usual but here goes
worse thing to do is constantly balance charge lipo`s every time
i used to balance charge every time years ago, but was told by a guy in the battery industry the worst thing to do is balance them to much.
since then i only balance charge if the cells are more than .03 of a volt out
which is very very rare, i have had a couple packs for 3-4 years still going strong that have never been balanced.
mind you i check voltage every charge and very rarely run till low voltage kicks in and i take care of by packs.
lipo quality has come a long way in the last 4-5 years and are not as temperamental or fragile as they once were.
Balancing is for wimps .

I only balance mine by sticking lead weights to them
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Old 06-30-2011, 06:38 AM   #5465
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Originally Posted by MICHAEL BROWN View Post
I only balance mine by sticking lead weights to them
I always balance charge them, otherwise 1 cell in your pack might be heavier then the other...
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Old 06-30-2011, 06:45 AM   #5466
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I always balance charge them, otherwise 1 cell in your pack might be heavier then the other...
does not matter when in series as once you plug it in the extra weight will split in half and automaticlly travel in to the other cell. its called lithium weight transference
its much better spending the time making sure the power wires are straight so the electricity gets a better flow
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Old 06-30-2011, 06:55 AM   #5467
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Originally Posted by ozzy-crawl View Post
does not matter when in series as once you plug it in the extra weight will split in half and automaticlly travel in to the other cell. its called lithium weight transference
its much better spending the time making sure the power wires are straight so the electricity gets a better flow

Thanks for the advise!

You can also better use as thin as possible power wires, so the flow of electricity goes faster, and so does your car!...
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Old 06-30-2011, 10:51 AM   #5468
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JKL1031
That was about the fans

Quote:
Originally Posted by COBRARACING View Post
seems like a voltage cut off even though its only for lipo but five minutes sounds correct for the voltage to drop very quickly on your nimh battery especially running a 5.5T motor
It has ran for about 10-15mins but the weather was a lot colder.
Need to look into Lipos, deffo, don't know a thing about lipos.
The Ni-mh does get a bit hot.

Quote:
Originally Posted by scoop View Post
What gearing are you running. Is the motor and or the esc really hot? Could be thermaling out.
Nope the speed controller isn't hot.. but the motor is.

Have got another version 2 to replace the version 1.
Now have 2 version 2 Ezrun combos, both 5.5t.

Would it be a good idea to drop the punch down and set the timing to 0degrees along with the neutral range set at 6%?

Edit, was going to put a pic up but not allowed to yet.
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Old 06-30-2011, 04:21 PM   #5469
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Originally Posted by ozzy-crawl View Post
going to get jumped on as usual but here goes
worse thing to do is constantly balance charge lipo`s every time
i used to balance charge every time years ago, but was told by a guy in the battery industry the worst thing to do is balance them to much.
since then i only balance charge if the cells are more than .03 of a volt out
which is very very rare, i have had a couple packs for 3-4 years still going strong that have never been balanced.
mind you i check voltage every charge and very rarely run till low voltage kicks in and i take care of by packs.
lipo quality has come a long way in the last 4-5 years and are not as temperamental or fragile as they once were.
I guess everyone has there own opinion which is good or this world would be stuffed lol.

But im a true believer they build lipos with a balance lead for a reason and thats for it to be used and used for a purpose.

I also know that technology in lipos has come a long way in the years gone by but i still know 70% of all lipos are still bad quality .I see it at the tracks every weekend especially Batterys coming out of the dongguan province of china .I wont mention any brands .

If the scientists who i read about on the internet who have invented the chemistry for lipo and life out of the US etc that highly recommend the use of balancing the cells must know something that us amatuars dont know right?

well anyway i just thought id post something up of my findings so others can read and know what to do when there lipos do drop below voltage .

Your input is highly appreciated and your experience could help someone out on the forum in the future .
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Old 06-30-2011, 05:53 PM   #5470
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From my experience, those lipos from china actually last better than the high end ones that seem to be care fragile. Ive had my china pack going on a year, treated it anyway I wanted besides not storing it too low. it hasnt swelled or anything. Maybe its because I didtnt race much..
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Old 07-01-2011, 02:19 AM   #5471
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ha ha i think lipos come from only a couple of factorys there all the same. bet some of those expensive packs use china made cells. balancing yeah personal opinion a pack wont die if its not balanced every time my chinese packs never balanced run in mod with no troubles. imo if cells need balancing because of cell voltage difference the pack is prob no good. two good cells in series should divide the charge evenly, and should not require balancing. dont aways work like that but in theory it should with perfectly matched cells. but little off topic now
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Old 07-01-2011, 02:33 AM   #5472
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Quote:
Originally Posted by Ian78 View Post
JKL1031
That was about the fans



It has ran for about 10-15mins but the weather was a lot colder.
Need to look into Lipos, deffo, don't know a thing about lipos.
The Ni-mh does get a bit hot.



Nope the speed controller isn't hot.. but the motor is.

Have got another version 2 to replace the version 1.
Now have 2 version 2 Ezrun combos, both 5.5t.

Would it be a good idea to drop the punch down and set the timing to 0degrees along with the neutral range set at 6%?

Edit, was going to put a pic up but not allowed to yet.
Would not run the gearing less than 7. Its the timing that causes the heat but if you get the gearing right and let the motor spin up you can add the timing back in. I would set the neutral at 6%.
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Old 07-01-2011, 02:47 AM   #5473
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I honestly don't think balancing your lipo's every time does all that much, in fact I think the less you fuss with them, the longer they may last, can't say for sure but I suspect when you balance and use storage after use constantly, maybe you work the cells more than you need to (it's just a theory though).

What I think really shortens life the most is running them low, high current draw, no rest time between usage, and excessive usage, but some of that is unavoidable.


And hey I finally got my hands on a Black Justock, wanted it for some time now, and it's nice, small and frees up room on my Photon chassis, good wiring layout, only gripe is I don't like pre-soldered wires on them, mainly cause by law I think they have to use lead free solder now, and I hate working with the stuff.
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Old 07-01-2011, 02:50 AM   #5474
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Quote:
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I would set the neutral at 6%.
Maybe, depending on your radio gear, I noticed some transition glitches at 6%, at 9% they go away, at least if you get some weird forward/brake behavior at 6% know going to 9% may fix it.
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Old 07-01-2011, 06:59 AM   #5475
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Originally Posted by Bishop View Post
I honestly don't think balancing your lipo's every time does all that much, in fact I think the less you fuss with them, the longer they may last, can't say for sure but I suspect when you balance and use storage after use constantly, maybe you work the cells more than you need to (it's just a theory though).
thats the inside tip i got from a manufacturer, less is best
also has some thing to do with the cell being constantly open whilst charging were balancing its open/closes open/closes as it balances.
but a lot i believe depends ( as you said)on how you treat them.

i used to run electric boats with constant amp draw up around 160-180 amps
one of the cheap Chinese brands was 99.9% as powerful as a few of the so called top brands, only difference was the cheap brand last about 30 times longer. $50 verses $300 Hmm
but as is known only china and Taiwan make lipos
so some of the best come from china
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