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"balancers are just a money grab"
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Slowkrawl
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"balancers are just a money grab" - 10.13.2009, 11:51 PM

So a buddy of mine has decided that balancers are useless. Apparently the guys on rc crawler have posted that balancers are just a money grab and are not needed. I full on, 100% DO NOT believe this for a second. But I'd like to know your guys' thoughts. I trust this forum over ANY other forum especially a ROCK CRAWLING forum where MAXAMPS is a major sponsor.... ... ...



-Matt

For the record, I am on RCC, and I know there are people on here from RCC. They are not stupid over there, however they build rock crawlers, not too many lipo nerds on there.

Last edited by Slowkrawl; 10.13.2009 at 11:54 PM.
   
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Arct1k
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10.13.2009, 11:56 PM

I'm on RCC to - The statement is just wrong...

There is a good write up on balancing in RC Driver (have to declare i write for them)...

Balancing ensures that over time voltages don't drift out of safe ranges ie a 2s pack drops to 2.6v and 3.4v in each cell - Total pack looks a healthy 6v

Balancing tells you when a pack is nearing its lifes end or is stressed - one cell is normally weaker than the rest

Balancing preserves the life of your pack

Balancing is good...

Last edited by Arct1k; 10.13.2009 at 11:58 PM.
   
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Slowkrawl
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10.13.2009, 11:59 PM

Not sure what you mean by "the statement is just wrong"? Also, I am not trying to start a flame war over RCC, just where the source of info came from... I have not checked out the site myself in a while, just that my buddy said "i stopped using a balancer when everyone on rcc did".

Personally, I have too much money into my 2 lipo's to take the chance.
   
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MetalMan
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10.14.2009, 12:05 AM

In some instances, where Lipo cells are perfectly matched and remain perfectly matched throughout the life of the pack, a balancer is truly useless.

A pack may seem like it remains in balance when a balancer does nothing, but if we don't monitor individual cell voltages, how will we know if a pack is balanced or not? There's no reason for us to constantly monitor the state of balance between cells in a pack if we have a balancer to take care of this task for us...

I think we need to go back to the basics and remember why cell balance is crucial:
-if a cell is overcharged its life may be shortened and there's the potential for rupture
-if a cell is overdischarged its life may be shortened which can result in this cell being overcharged in future use

So if an imbalanced pack is being charged, it's possible a cell will be overcharged past its tolerant limit. If an imbalanced pack is being discharged to the LVC point, it's possible a cell will be overdischarged.

High power setups often can weed out weaker cells and cause imbalances to worsen over time. Rock crawlers are not a high power application, and thus over the life of a Lipo pack imbalance may not be an issue.

Since we cannot be sure that a pack was built with identical cells, we have no way of knowing whether or not it will remain properly balanced. A balancer is "cheap" insurance because it can provide more cycles over the life of a pack and potentially prevent catastrophe.

However, Lipo packs of today are not the same packs of several years ago. Nowadays Lipos tend to be more tolerant and from what I've seen imbalance has been less of an issue. But IMO that's not a reason to disregard a $25-40 balancer...

To not use a balancer is like a biker choosing not to wear a helmet because he doesn't think he will crash. Sure, in Hawaii helmets aren't necessary, but the biker must assume the risk. Though he/she will never be able to completely anticipate future potential situations while out riding.


SH Z-Car, Custom Crawler, 8s Savage, 12s XTM XLB 1/7 buggy, 4wd 4-link rear/IFS Pro4 truck, Custom Hyper 10 Short Course, Belt-Drive Mammoth ST 1/8 truggy, 4s 17.5 MM Pro HPI Blitz

Last edited by MetalMan; 10.14.2009 at 12:08 AM.
   
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lincpimp
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10.14.2009, 12:11 AM

Well, the crawler guys do not draw their packs very hard, that is how they get away with using maxamps overpriced, overrated crap. So as long as they do not over discharge the packs, and have well matched cells (not a good chance of that with maxamps either) then they may not need a balancer.

However, having a piece of equipment that can monitor each cell during the charge, and interrupt the charge should one cell go under or over voltage is just a good idea. That will go along way to prevent lipo fires (they get real hot when you overcharge them) and damaged packs.

I bet none of the hicks over there that have done this have half a clue about lipo useage and saftey. Not that I care, just their money they are tossing out..

I think it was apogee that had some sort of info on their site that said that properly matched cells would never go out of balance. I have noticed this with my enerland cell based packs, they take little to no balancing when I use the 610i hyperion.
   
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Slowkrawl
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10.14.2009, 12:15 AM

Quote:
Originally Posted by MetalMan View Post
In some instances, where Lipo cells are perfectly matched and remain perfectly matched throughout the life of the pack, a balancer is truly useless.

A pack may seem like it remains in balance when a balancer does nothing, but if we don't monitor individual cell voltages, how will we know if a pack is balanced or not? There's no reason for us to constantly monitor the state of balance between cells in a pack if we have a balancer to take care of this task for us...

I think we need to go back to the basics and remember why cell balance is crucial:
-if a cell is overcharged its life may be shortened and there's the potential for rupture
-if a cell is overdischarged its life may be shortened which can result in this cell being overcharged in future use

So if an imbalanced pack is being charged, it's possible a cell will be overcharged past its tolerant limit. If an imbalanced pack is being discharged to the LVC point, it's possible a cell will be overdischarged.

High power setups often can weed out weaker cells and cause imbalances to worsen over time. Rock crawlers are not a high power application, and thus over the life of a Lipo pack imbalance may not be an issue.

Since we cannot be sure that a pack was built with identical cells, we have no way of knowing whether or not it will remain properly balanced. A balancer is "cheap" insurance because it can provide more cycles over the life of a pack and potentially prevent catastrophe.

However, Lipo packs of today are not the same packs of several years ago. Nowadays Lipos tend to be more tolerant and from what I've seen imbalance has been less of an issue. But IMO that's not a reason to disregard a $25-40 balancer...

To not use a balancer is like a biker choosing not to wear a helmet because he doesn't think he will crash. Sure, in Hawaii helmets aren't necessary, but the biker must assume the risk. Though he/she will never be able to completely anticipate future potential situations while out riding.
I thought this had been the basic understanding for quite a while now...It's not ALWAYS necessary to balance a pack, but why not? It sounds bad, but I hope ignorance comes to bite my buddy in the ass. He even has a blinky balancer and is just too ignorant/lazy to use it.
   
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lincpimp
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10.14.2009, 12:37 AM

Well, A blinky is just about useless from a safety standpoint. Plus it does nothing to provide you with actual info. It is a dinosaur and should only be used with an astro 109 (inside joke).

Buying a decent charger is one of those things that should be federally mandated, just ditch the 2 oz per flush toilets, make people buy decent lipo chargers and give me back that old toilet that could handle a mature sheep in a single flush!!!

When all of the "lipo pros" over at RCC start puffing their maxamps packs they will start blaming everything under the sun save for the lack of pack monitoring. I cannot belive that old Jason has not stepped in and preached to them that balancers are needed (especially with maxamps packs). I 75% discharged a maxamps 10000 mah pack about 2 years ago and it took 27hrs to balance, and then needed balancing during and after a full charge.

Bottom line, if you are not using a good charger and at least a charge thru balancer (like a lba6 or 10 equinox, checkpoint, v balancer, etc) you are running the risk of a puffed pack, or possibly a lipo fire. Stand alone balancers are a thing of the past, we are not clinging to 10c lipos (save for the maxamps cult) why not move on with charge equipment as well.
   
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Finnster
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10.14.2009, 01:16 AM

hey hey hey.. don't bash the blinky!
Don't blame the tool, but blame the user. If you are trying to use a wrench as a hammer, expect some bent nails. I love my blinky as I know how to use it and know it will balance anything, but you don't use it to charge @ 5C to 100% on a pack you just pulled 25C from to LVC. 0.1" pins FTW. You need a smart balancer/charger in the toolbox as well.

Not using a balancer is silly and lazy. The more modern cells are much better and safer than the ones from just a short while back, but not using a balancer won't save you anything long term. IDK know why someone would pay hundreds of $ for a lipo then treat it like a duratrax NIMH. Whatever, your money, your house. g/l
   
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Arct1k
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10.14.2009, 07:33 AM

Ps crawlers do pull some amps - my berg runs dual 35t on 3s with a 7950th on 7.5v from a 1100mah battery...
   
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Bondonutz
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10.14.2009, 10:29 AM

Here's one to make you think ?
One of my buddys whom I rarely see for RCing due to his schedual asked me to take a look at his packs. He has a TP 3s 3850mah and a Venom 3s 4000mah. These packs are over 2 years old and never seen a balancer, he uses a Multiplex charger only.
All the cells in both packs had 4.18volts when checked with voltmeter. That blew me away ? These packs are run hard in a Slash once every few months and the packs are stored at full charge for months at a time.
Is that dumb luck or he's super lucky with his packs qaulity ?????


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lincpimp
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10.14.2009, 10:33 AM

Quote:
Originally Posted by Finnster View Post
hey hey hey.. don't bash the blinky!
Don't blame the tool, but blame the user. If you are trying to use a wrench as a hammer, expect some bent nails. I love my blinky as I know how to use it and know it will balance anything, but you don't use it to charge @ 5C to 100% on a pack you just pulled 25C from to LVC. 0.1" pins FTW. You need a smart balancer/charger in the toolbox as well.

Not using a balancer is silly and lazy. The more modern cells are much better and safer than the ones from just a short while back, but not using a balancer won't save you anything long term. IDK know why someone would pay hundreds of $ for a lipo then treat it like a duratrax NIMH. Whatever, your money, your house. g/l
Yeah, I know what a blinky can do. I would not use one during the charge as it will not interrupt the charge if necessary. And I would never balance a pack after the charge, so it is not much use. You could use it to balance a partially discharged pack if said pack is way off, but I would rather use the balancing function of my 610i, as it will show me info as well as balance the pack. So a blinky is not much use to me. Old tech, plus you should balance packs during the charge, and a blinky is not optimum for this either. I have a few stand alone balancers, but all have digital screens that show individual voltages.

Quote:
Originally Posted by Arct1k View Post
Ps crawlers do pull some amps - my berg runs dual 35t on 3s with a 7950th on 7.5v from a 1100mah battery...
Yes, some crawlers do pull amps. I remember JRH doing tests to substantiate that claim. I am guessing most of these guys that are "saving" some money are running more simple single motor setups that are not as hard on batteries. I can imagine super class rigs can pull some juice too, but nothing like a flux on 4s can...
   
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lincpimp
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10.14.2009, 10:35 AM

Quote:
Originally Posted by Bondonutz View Post
Here's one to make you think ?
One of my buddys whom I rarely see for RCing due to his schedual asked me to take a look at his packs. He has a TP 3s 3850mah and a Venom 3s 4000mah. These packs are over 2 years old and never seen a balancer, he uses a Multiplex charger only.
All the cells in both packs had 4.18volts when checked with voltmeter. That blew me away ? These packs are run hard in a Slash once every few months and the packs are stored at full charge for months at a time.
Is that dumb luck or he's super lucky with his packs qaulity ?????
The thunderpower pack does not surprise me, I have left enerland cell based packs sit for 6 months fully charged and they have lost very little voltage and always stayed in balance.

As for the venom pack, I have no experience with the 4000 mah cells, but the little 1800 cells were pretty good. They did not last very long, but I was pulling them pretty hard.
   
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hoober
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10.14.2009, 06:33 PM

Quote:
Originally Posted by Bondonutz View Post
Here's one to make you think ?
One of my buddys whom I rarely see for RCing due to his schedual asked me to take a look at his packs. He has a TP 3s 3850mah and a Venom 3s 4000mah. These packs are over 2 years old and never seen a balancer, he uses a Multiplex charger only.
All the cells in both packs had 4.18volts when checked with voltmeter. That blew me away ? These packs are run hard in a Slash once every few months and the packs are stored at full charge for months at a time.
Is that dumb luck or he's super lucky with his packs qaulity ?????
All my packs are the same way , I check them once per year and balance them if needed. I have a range of mostly cheap, budget and many used packs that I bought used. Some of them are very cheap e-bay type packs. The cell match is nice on some, and terrible on others. Cell match has no bearing on cell balance as long as the pack was once balanced. I have a balancer that lives in it's box , and I don't even use it to balance. If ones packs are out by more than .1 volts then something serious is wrong and needs to be investigated.
   
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zeropointbug
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10.14.2009, 06:59 PM

Simply put, a balancer is a long term insurance on your lipo packs.

I have been charging my 2 G3 3s lipo packs as a 6s pack, non-balance mode, intentionally didn't balance them for roughly 20 cycles, I just checked them last night, nothing, as soon as I plug it in, the 720i balance mode says complete on both packs after a short pause. So there you go, if a pack is matched, it is far from crucial to use balancing every charge.


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redshift
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10.14.2009, 08:05 PM

linc: "Buying a decent charger is one of those things that should be federally mandated"

After spending most of a year with my 0610i I fully agree. AS much as I don't want gov't messing in my RC, this literally should be controlled.

I want to add also I think it's critical to use ONLY a balance charger at anything over a 1C rate. I have charged my Hyperion 20C 2S 4000 packs at 2.5C (10 amps) but normally charge at 2C, absolutely zero issues. These are packs rated for 1C charge, and I have no less than 80 cycles on the four packs I own. They have always been charged with at least 2C. If extreme out-of-balance conditions arise due to an internal or external short or broken circuit, the good chargers will let you know.

Again I would not charge over 1C with anything other than a balance charger. Like linc said, spend the $ on the charger, it's even more important when you are using lesser-name packs.
   
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