Lipo battery use update. SMC gets ?

[Danny/SMC]

The irony here is we have had an abundance of users here complaining that their LVC is kicking in too soon. ??‍?

Again, we greatly appreciate the time you have taken to help us understand your products better.

If I may take another moment of your time, how is it that your Premium packs are so much lighter than other packs with the same rating?

When it comes to LVC there are a few things that impact the cutoff. One of them is the IR of the cells. Higher IR cells mean the voltage drop will be more so the cutoff will happen earlier. Second the wire length and condition of the connector will impact the overall resistance so once again the voltage drop can be higher or lower due to how well the pack connects to the ESC. The last thing that impacts the cutoff is the ambient and pack temperture. The colder the temp the higher the voltage drop will be as colder cells have an increase in IR. The cool thing about our Precision Lipo Alarm is that you can adjust it to where it needs to be at and since it measures the cell voltages at the balance connector you by pass the resistance of the wires and connectors so you get a precise cutoff.

The 5000 Premium packs are made with thin cells so we can offer a 3S pack in a 2S case. So these use materials that increase mAh and lowers the IR for a specific cell size. We then have a 6200 pack which is more like a true 5800 as the factory wasn't able to achieve the estimated mAh when making these cells as they made them a bit to thin. Once again these use materials to increase the mAh and not the size of the cell. So cells that are thinner will not be as heavy.

I posted the TLDR version of this a page prior.



I still think that issue is more battery related than esc related.

You can have the same brand/model ESC in different vehicles and they can cutoff at different voltages even if they are set at the same voltage. As mentioned in the previous post I just made the wire length and condition of the connector have an impact on the LVC.

I've used the top expensive SMC, but I don't buy them, too expensive. The set I got with an E-Revo puffed and one had a cell failure.

After the SMC I got some cheap ass Floureon and could not tell any difference.

I've used HRB and Power Hobby, Hobbystar, gensacearespammers, now Goldbat. They all perform the same. I just buy whatever is cheapest within specs I need. If they puff or go bad I don't care, just buy another cheap one. Usually the cheapest option costs about 1/3 to 1/2 of what SMC and other "premium" brands want.

Which model of ours did you use in your E-Revo and have issues with ? Did you contact us about the pack with cell failure as if it's within one year of date of purchase this is covered under our warranty ? Are you running the Traxxas ESC ?

 

[slick2500]

I've used the top expensive SMC, but I don't buy them, too expensive. The set I got with an E-Revo puffed and one had a cell failure.

After the SMC I got some cheap ass Floureon and could not tell any difference.

I've used HRB and Power Hobby, Hobbystar, gensacearespammers, now Goldbat. They all perform the same. I just buy whatever is cheapest within specs I need. If they puff or go bad I don't care, just buy another cheap one. Usually the cheapest option costs about 1/3 to 1/2 of what SMC and other "premium" brands want.

Could be worse he could have bought a Maxamps 5450mah 6s for $250........what a bunch of crooks.

When it comes to LVC there are a few things that impact the cutoff. One of them is the IR of the cells. Higher IR cells mean the voltage drop will be more so the cutoff will happen earlier. Second the wire length and condition of the connector will impact the overall resistance so once again the voltage drop can be higher or lower due to how well the pack connects to the ESC. The last thing that impacts the cutoff is the ambient and pack temperture. The colder the temp the higher the voltage drop will be as colder cells have an increase in IR. The cool thing about our Precision Lipo Alarm is that you can adjust it to where it needs to be at and since it measures the cell voltages at the balance connector you by pass the resistance of the wires and connectors so you get a precise cutoff.

The 5000 Premium packs are made with thin cells so we can offer a 3S pack in a 2S case. So these use materials that increase mAh and lowers the IR for a specific cell size. We then have a 6200 pack which is more like a true 5800 as the factory wasn't able to achieve the estimated mAh when making these cells as they made them a bit to thin. Once again these use materials to increase the mAh and not the size of the cell. So cells that are thinner will not be as heavy.


You can have the same brand/model ESC in different vehicles and they can cutoff at different voltages even if they are set at the same voltage. As mentioned in the previous post I just made the wire length and condition of the connector have an impact on the LVC.


Which model of ours did you use in your E-Revo and have issues with ? Did you contact us about the pack with cell failure as if it's within one year of date of purchase this is covered under our warranty ? Are you running the Traxxas ESC ?

I just mentioned the battery because we do have a lot of guys who buy those random no name lipos and they use adapter plugs a lot as not a lot of these companies sell batteries with EC5 or IC5 connectors. Most of them use knockoff deans same goes for the adapter plugs. Most of the time the cheapo batteries have umatched, unbalanced low quality cells and the afor mentioned crappy knockoff connectors.

It sounds like he bought the revo used and most likely the batteries were used and abused before he got them.

 

[Danny/SMC]

Could be worse he could have bought a Maxamps 5450mah 6s for $250........what a bunch of crooks.

I just mentioned the battery because we do have a lot of guys who buy those random no name lipos and they use adapter plugs a lot as not a lot of these companies sell batteries with EC5 or IC5 connectors. Most of them use knockoff deans same goes for the adapter plugs. Most of the time the cheapo batteries have umatched, unbalanced low quality cells and the afor mentioned crappy knockoff connectors.

It sounds like he bought the revo used and most likely the batteries were used and abused before he got them.

Good point I forgot about adapters they will also increase resistance and voltage drop but if our precision lipo alarm is used this will by pass the voltage drop due to wires , adapters and connectors.

 

[jondilly1974]

Danny this is all great info.

 

[Danny/SMC]

This thread has made me think about our battery lineup. Seems that many only care about bottom price when it comes to packs and are not concerned about warranty if something it wrong with the packs since the price is lower. I would like to know if customers would buy packs from SMC at the lower pricing with no warranty ? It's easy for us to buy from the few factories who make these lower priced cells/packs but I was always under the impression it was better to sell packs with higher grade materials and offer a warranty against defects as there is no Lithium factory who makes 100% defect free cells. In fact SMC tests every pack prior to shipping to make sure the cells are at proper voltage and the IR are within the proper specs. We have around 2% of the packs we get in that don't pass testing due to cells with issues. This rate is pretty normal for Lithium cells especially since they are done by factories who do RC cells. These factories are not as sophisticated as the factories who make high end consumer cells or cells for real cars. In fact even the high end factories who make Lithium cells for real cars have a percentage of cells that are defective.

 

[Kenblazer318]

SMC is not what it used to be, I had 2 7200mah 2s 60c that lasted about 3yrs at roughly 6-700 cycles each until they didn't want to charge properly, so I bought another one exactly the same been less then a year at maybe 150 cycles already puffing the hard case but still works properly. My buddy has blown out 3 of the 4 he bought in the last 2 years. Neither of us will buy SMC again he bought 2 you&me brand half the price works just as good if not better so far, well see- not sure what im gonna buy!

 

[olds97_lss]

Thoughts on HRB batteries anyone?

I've been running 4 of the 3S 5000mah 50C packs in my ERBEv2 and Outcast 6S since Spring and they seem to do fine. I also run hobbystar 6200mah 50C 3S packs, which perform a bit better, but the added weight is something I'll avoid in the future when they die. I've been running them about as long as the HRB's and now I only run the 6200's in my outcast as the ERBEv2 holds up better with less weight.

 

[Lefty_Al]

I use Turnigy Nanotech 4200 hard case batteries for most of my cars. They have 2 discharge rates, so the lower ones for the stockers and the higher ones for the modified cars.
Have started using their Heavy Duty ones for the boy's Outcast 6S. a 5000mAh 4S and 2 4000Mah 3S. Very happy with the performance and charging of them.
I am sure that just about every issue I have had with any lipo battery has been more about not treating them right (putting into storage charge etc) vs poor batteries.
In AU HobbyKing/Turnigy batteries are hard to beat for price and performance wise (only bashing) I am quite happy with them.

 

[olds97_lss]

I used to run only SMC packs for about 3 years. Still have 8 or so of them, 4 of which are the hard case 2S 7400 packs that I'll break down to make 3S packs out of for my smaller trucks now that I run 3S or 6S only. I had one of my first SMC's die on me after about 14 months ran in my v1 revo. One of the cells dropped out and wouldn't hold a charge. All 4 of my 9000mah 2S packs I bought back then puffed a bit and didn't fit well in the revo after about 6 months which is when I switched to the 7200 (then later bought 7400) 2S packs.

I think out of the 14-16 I've bought only 2 have dropped a cell and that was after a year or more of abuse. Always charged at a bit more than 1C (10A into 7200/7400 2S packs) and storage charged after every bash even if I was planning to use them the next day.

I only started running other brands because at the time I needed 3S packs, they didn't have the size in stock that I needed, so I went with what was cheap, hrb 5000mah 50C and hobbystar 6200mah 50C. So far, they have held up fine, both with 9 months of use on them in 3 of my 6S trucks. Will see how they last.

 

[Danny/SMC]

SMC is not what it used to be, I had 2 7200mah 2s 60c that lasted about 3yrs at roughly 6-700 cycles each until they didn't want to charge properly, so I bought another one exactly the same been less then a year at maybe 150 cycles already puffing the hard case but still works properly. My buddy has blown out 3 of the 4 he bought in the last 2 years. Neither of us will buy SMC again he bought 2 you&me brand half the price works just as good if not better so far, well see- not sure what im gonna buy!

We stopped offering the 7200-60C over 2 years ago so if you bought a 7200-60C last year it wasn't off the SMC site. When buying batteries it's important to make sure they are fresh and haven't been sitting ona shelf for over a year as all batteries detoriate when sitting unused for extended periods of time. This is why we run out of packs from time to time it's not because we can't stock more packs it's because we want to offer fresh packs. If you have read all my posts in this thread so far I did mention that our DV series packs have more empasis on reliablity at the expense of some performance. This has been done as we realize the new power systems in todays are RC are much more demanding then in the past so the cell formulation must be different. Also when claiiming a certain brand is better then another there are things to consider such as the mAh of the cell versus the size of the cell. This has a big impact on how the cell holds up. When trying to make cells that fit a certain size and increase the mAh you must make the layers thinner to increase the mAh this can impact how the cell will hold up so it's allot more complicated then it seems. So a 7200mAh pack with cells that fit s standard 2S case which is 25x47x139 is allot harder to make then a 5000 or 6000mAh cell that fits the same case. When comparing packs the only true way to compare them is to go with the same mAh , size and weight and then see what packs give you the best results. For example we sell a 5200 pack under our Premium series this pack has very low IR for a 5200 of this weight and price. We also sell a 5200 under our Extreme Graphene series which is a heavuer pack and costs more. The Extreme pack has even lower IR and comparing both makes no sense.

 

[Kenblazer318]

When it comes to Lipo batteries there are many things that can account for them expanding and swelling. At SMC we have always focused on providing packs with higher performance as we typically want to sell packs that make a difference. That being said with the new breed of RC kits that are bigger and have more high power systems we had to reconsider our pack lineup. When selling packs with more power this means the cells have lower internal resistance. This equates to less voltage drop under load so the packs will discharge more under load as the cutoff will not kick in as early. The RTR ESCs supplied by most companies don't have an adjustable cutoff and cutoff to low. Running cells to low under load increases the chance of cell damage and cell expansion.

We released the DV series to accomodate the new breed of vehicles and the cells in these packs focus on maximum reliability at the expense of some performance but feedback has been very good on these so far. We also have very good info on our site under the Technical Info section on the top bar. For those who want to better understand Lipos this can be very helpful.

The pack shown in the first post is one of our 5000-6S Premium series which focuses on low IR to maximize voltage under load. These are small cells designed to fit a 3S in the standard 3S case and a 4S in the 3S case and 6S in 4S case. Tyipcally guys who run normal 1/10th size vehicles where a 2S pack size is required and want to go with 3S will use these smaller packs. We also sell these as a low center of gravity race pack for 1/8th scale offroad racing so you get a light and thinner 4S pack. The 6S pack can be run in a 1/8th scale buggy where a 4S pack will fit. So these are the main applications for these packs. We do offer under the DV series a 6500-6S and 8000-6S that are designed to fit in the Arrma vehicles listed in the Arrma Battery guide on the top bar of our site. These are bigger cells and under the DV series makes them more reliable. I suspect some will not want to buy these as they cost more the 5000-6S but these should be the packs used Arrma 6S kits. To compare our smaller 5000-6S pack with any other pack that is made with bigger cells is not a fair comparison. We have sold hundreds of these new 5000s and so far we have not heard any negative issues about them. That being said there is always the certain applications where a certain model of pack can have issues. For example if you run the packs down to low and use them in very demanding conditions like tall grass or sticky mud this puts allot more stress on the packs due to the amp draw being higher. In these applications a bigger pack will do better for sure.

I've been selling RC packs for over 30 years and have my own testing equipment and I can tell you that there is no company/factory that makes 100% perfect cells and there will always be the chance of cells going bad due to manfacturing defects. This is why we offer a one year warranty against manufacturing defects. If a cell shorts out which is one of the most common issues with Lipo cells we will take care of it within the first year of purchase. Many of our competitors will not warranty packs when a cell has an issue. Also when it comes to the very low priced packs you must be careful as most of them are not made using premium materials in fact RC grade cells are made with Lithium Cobalt Oxide in the cathode and many of these very low priced packs use some sort of substitute for Lithium Cobalt Oxide which decreases the cycle life. We can easily offer these packs at the same prices as others do but we believe this is not worth it. You might as well pay a bit more and get a real Lithium Cobalt Oxide pack that has a warranty.

Hope this post can help some better understand Lipo packs and if you check out our Technical Info section on the top bar of our site I think you will get even more knowledge.

Right on thankyou, maybe I'll try a DV pack! I really liked my first 2 SMC packs, third one not so much, and im the reason my buddy bought his that he blew out 3 of 4 so not sure but thankyou.

 

[Danny/SMC]

I used to run only SMC packs for about 3 years. Still have 8 or so of them, 4 of which are the hard case 2S 7400 packs that I'll break down to make 3S packs out of for my smaller trucks now that I run 3S or 6S only. I had one of my first SMC's die on me after about 14 months ran in my v1 revo. One of the cells dropped out and wouldn't hold a charge. All 4 of my 9000mah 2S packs I bought back then puffed a bit and didn't fit well in the revo after about 6 months which is when I switched to the 7200 (then later bought 7400) 2S packs.

I think out of the 14-16 I've bought only 2 have dropped a cell and that was after a year or more of abuse. Always charged at a bit more than 1C (10A into 7200/7400 2S packs) and storage charged after every bash even if I was planning to use them the next day.

I only started running other brands because at the time I needed 3S packs, they didn't have the size in stock that I needed, so I went with what was cheap, hrb 5000mah 50C and hobbystar 6200mah 50C. So far, they have held up fine, both with 9 months of use on them in 3 of my 6S trucks. Will see how they last.

There are a few things that cause a cell to drop off one of them is manufatcuring defect and this will happen wihen the pack is relatively new and this is covered under our 1year warranty. If the pack is older and has a good amount of cycles on them this is due to dendrite formation which shorts out the cell. The best way to prevent this is to not discharge the cells to low under load wich most users tend to do as the cutoffs are to low in the RTR ESCs. Another thing to note is the Premium packs you got were made using oil in the cells to lower IR. Cells with oil tend to expand easier then cells without oil. The upside of oil is that it increases the power of the cell. When we realized that the newer RC kits are cmoning out with more powerful setups we decided to release the DV series which are cells with no oil so this increases the reliability of the cells at the expense of some performance. Please note these are still powerful packs as they are made using real Lithium Cobalt Oxide and not the cheaper substitute found in many of the lower priced packs.

 

[Kenblazer318]

We stopped offering the 7200-60C over 2 years ago so if you bought a 7200-60C last year it wasn't off the SMC site. When buying batteries it's important to make sure they are fresh and haven't been sitting ona shelf for over a year as all batteries detoriate when sitting unused for extended periods of time. This is why we run out of packs from time to time it's not because we can't stock more packs it's because we want to offer fresh packs. If you have read all my posts in this thread so far I did mention that our DV series packs have more empasis on reliablity at the expense of some performance. This has been done as we realize the new power systems in todays are RC are much more demanding then in the past so the cell formulation must be different. Also when claiiming a certain brand is better then another there are things to consider such as the mAh of the cell versus the size of the cell. This has a big impact on how the cell holds up. When trying to make cells that fit a certain size and increase the mAh you must make the layers thinner to increase the mAh this can impact how the cell will hold up so it's allot more complicated then it seems. So a 7200mAh pack with cells that fit s standard 2S case which is 25x47x139 is allot harder to make then a 5000 or 6000mAh cell that fits the same case. When comparing packs the only true way to compare them is to go with the same mAh , size and weight and then see what packs give you the best results. For example we sell a 5200 pack under our Premium series this pack has very low IR for a 5200 of this weight and price. We also sell a 5200 under our Extreme Graphene series which is a heavuer pack and costs more. The Extreme pack has even lower IR and comparing both makes no sense.

Im sorry it puffed in less then a year, and still works today!

 

[Danny/SMC]

Right on thankyou, maybe I'll try a DV pack! I really liked my first 2 SMC packs, third one not so much, and im the reason my buddy bought his that he blew out 3 of 4 so not sure but thankyou.

I think you will be very happy with our DV packs we have packs for all the popular vehicles and like all our packs we offer a 1 year warranty against manufactruring defects such as a cell that shorts out. You still need to treat these packs properly to get the most out of them so I recommend not discharging them down to low under load. Ideally you want the cells to be in the high 3.6 to low 3.7 range as soon as your LVC cuts in. Don't leave them stored fully charged and store them in a cool/dry place. If you do this you will get better cycle life out of any Lipo you buy.

Im sorry it puffed in less then a year, and still works today!

Are you sure it's a 7200-60C that was bought a year ago ? We stopped selling 7200-60C 2 or 3 years ago. We replaced these with a 7400-90C with more power and I will admit this move wasn't the best move for us as we didn't understand how todays kits use more power and come with ESCs that cut off to low. By increasing the power of the cells this means they will discharge down deeper under load as the voltage drop will be less. Once we understood this we worked on the DV series which is better suited for todays market. That being said our Premium V2 packs which we only offer a few models do offer very good power for the weight/mAh but I wouldn't recommend these to be used on the bigger and heavier models.

 

[Kenblazer318]

I think you will be very happy with our DV packs we have packs for all the popular vehicles and like all our packs we offer a 1 year warranty against manufactruring defects such as a cell that shorts out. You still need to treat these packs properly to get the most out of them so I recommend not discharging them down to low under load. Ideally you want the cells to be in the high 3.6 to low 3.7 range as soon as your LVC cuts in. Don't leave them stored fully charged and store them in a cool/dry place. If you do this you will get better cycle life out of any Lipo you buy.


Are you sure it's a 7200-60C that was bought a year ago ? We stopped selling 7200-60C 2 or 3 years ago. We replaced these with a 7400-90C with more power and I will admit this move wasn't the best move for us as we didn't understand how todays kits use more power and come with ESCs that cut off to low. By increasing the power of the cells this means they will discharge down deeper under load as the voltage drop will be less. Once we understood this we worked on the DV series which is better suited for todays market. That being said our Premium V2 packs which we only offer a few models do offer very good power for the weight/mAh but I wouldn't recommend these to be used on the bigger and heavier models.

I think I have my sidewinder 3 cutoff set to 3.4, and I always either charge and reuse or put in storage. Maybe I'll bump it up a bit freaking battery last forever anyway!

 

[slick2500]

I think I have my sidewinder 3 cutoff set to 3.4, and I always either charge and reuse or put in storage. Maybe I'll bump it up a bit freaking battery last forever anyway!

I set mine at 3.5-3.6v depending on the vehicle as even 3.4 can be a bit low I find.

 

[VPR01]

I’ve learned a lot reading thru this thread, and appreciate all the information. I respect that SMC/Danny is providing information up front in a market that’s probably challenging to corner. I’m always interested in checking out innovation at its finest knowing there’s a risk involved with performance (which can be applied to many different topics/threads). Without companies like SMC and others in this hobby constantly searching for innovative cells & next generation charge capacities we kinda lose the concept sitting at our work bench sanctuary that this engineered machine in front of us was the result of simple engineering or trial/error. Thanks for passing along the knowledge.

 

[drjim]

Thank you, Danny, for coming here and explaining not only LiPo batteries, but also your company policies regarding what you sell, and why.

I only have two SMC packs, and they're "only" 2S, but I'm happy with them. I use them in my VTA car and my Senton interchangeably, and they work fine. I really appreciated the instruction sheets that came with them, as it explains a lot of things I didn't know about this application for LiPos.

I'm a retired EE, so I understand E=IxR pretty well, along with little "gotchas" like the extra series resistance that even good quality adapters will cause, not to mention poorly soldered connections.

When you consider the amount of stored energy in a 6S pack, and how fast these modern systems can suck the current out, you have to tray and get all your ducks in a row to use them safely and reliably.

 

[RSM801]

While I personally wont purchase SMC packs due to all mine puffing. They were still good packs and had good punch, but they all puffed with just casual use. I have 4 of the packs, so maybe my experience isnt common since I only tried 4 of them, and they probably all came from the same batch as they were purchased about the same time as each other. But it wasnt a good picture for me.
This was Racing once a week with the 2s shorty packs. never even got close to LVC and always put in storage. They would still swell. Not crazy puffing, but noticeable puffing on each side none the less.
My other racing packs haven't swelled at all after 8 moths of weekly use.

I do love my SMC motors and SMC esc's and its a shame SMC got out of the motor and esc business, but I understand why. I just wish I would have gotten more of them, lol.

I will also say that I think it speak volumes that Danny ( @Danny/SMC ) came here to discuss their batteries.
Its awesome when companies have a voice with the community and it means the world to hobbies like this.
Ive had email exchanges with Danny and I know hes a stand up guy, and SMC is a stand up company that stand by their goods.

I have not tried any SMC packs for bashing, so I cant comment on that.

Thanks again Danny for coming here.

 

[Kenblazer318]

I set mine at 3.5-3.6v depending on the vehicle as even 3.4 can be a bit low I find.

Right on I'll bump it up to 3.6, thankyou