Oh #%@!! What did I do to my SMC Lipos?

[lincpimp]

And FB, keep the language a little more PG... We do have younger members.

I feel your frustration, and have been through this exact lipo issue with maxamps a while back. Weak packs will cause all kinds of grief...

[fastbaja5b]

yeah he was asking me how both A123 packs failed when I had them, and to that, the only thing I can think of is a faulty charger, as they were fine when I used my Lipo - A123 / Nimh charger but failed once I used their proprietory "A123 Hypersonic" charger.

[zeropointbug]

Originally Posted by fastbaja5b

yeah he was asking me how both A123 packs failed when I had them, and to that, the only thing I can think of is a faulty charger, as they were fine when I used my Lipo - A123 / Nimh charger but failed once I used their proprietory "A123 Hypersonic" charger.

Could very well be the charger, I never liked the looks of those things from day one. I have used a programmable lab quality power supply to charge my A123 packs, very accurate and reliable.

[JThiessen]

Originally Posted by fastbaja5b

yeah he was asking me how both A123 packs failed when I had them, and to that, the only thing I can think of is a faulty charger, as they were fine when I used my Lipo - A123 / Nimh charger but failed once I used their proprietory "A123 Hypersonic" charger.

Did you by chance purchase those on Ebay from "hopmeup"? If so, I'm guessing you were one of many who ended up buying old cells. There was a thread on this a year or so back. I bought six packs from them, and ended up with 4 after I rebuilt them and pulled out the bad cells.

Back to the topic at hand - Freeze ya need a break from this. Still not an excuse to use language like that.
I for one have a hard time thinking that both packs puffing at the same time is due to bad cells. If it is, you definitley got some bad mojo going.

[fastbaja5b]

Originally Posted by JThiessen

Did you by chance purchase those on Ebay from "hopmeup"? If so, I'm guessing you were one of many who ended up buying old cells. There was a thread on this a year or so back. I bought six packs from them, and ended up with 4 after I rebuilt them and pulled out the bad cells.

Back to the topic at hand - Freeze ya need a break from this. Still not an excuse to use language like that.
I for one have a hard time thinking that both packs puffing at the same time is due to bad cells. If it is, you definitley got some bad mojo going.

Yeah I did actually, likely a contributing factor!

Can you run a 3s and a 2s on the Flux? The manual says both pack needs to be equal. I didn't think I could even run a 5000mah and a 5100mah pack or a 28C and a 30C pack, what I interpreted was both packs must be identical.

[skellyo]

Originally Posted by fastbaja5b

Can you run a 3s and a 2s on the Flux? The manual says both pack needs to be equal. I didn't think I could even run a 5000mah and a 5100mah pack or a 28C and a 30C pack, what I interpreted was both packs must be identical.

Yes, you can run a 2S and 3S in there without an issue. They must be the same brand, capacity and C rating though. I run 2S and 3S 25C Thunder Power 5000's in mine.

[JThiessen]

Originally Posted by fastbaja5b

Yeah I did actually, likely a contributing factor!

Can you run a 3s and a 2s on the Flux? The manual says both pack needs to be equal. I didn't think I could even run a 5000mah and a 5100mah pack or a 28C and a 30C pack, what I interpreted was both packs must be identical.

I was banned by hopmeup on ebay because I left them neutral feedback based on the quality of the product they were selling. Dont base your opinion of A123's on what you got from them - they really are good reliable power. Not as much power as lipo, but likely much more reliable.

To do a 2S/3S set up (as 5S), you just need to remove the Flux battery wires, and insert a single pack connector - this will make the flux think it is seeing one pack. Oh, and you'll need a series wiring connector for the packs (or is that parallel???) Check Brians speed calculator page on battery wiring to verify the layout.

[skellyo]

Originally Posted by JThiessen

To do a 2S/3S set up (as 5S), you just need to remove the Flux battery wires, and insert a single pack connector - this will make the flux think it is seeing one pack. Oh, and you'll need a series wiring connector for the packs (or is that parallel???) Check Brians speed calculator page on battery wiring to verify the layout.

You don't need to do anything. Just use a single 2S pack and a single 3S pack and use the existing connectors on the Flux ESC. They'll plug right in and be in series for 5S operation. If you do what you stated to modify the connection, you've just wasted your time since it's the same electrically regardless of where the series connection is.

[fastbaja5b]

Originally Posted by JThiessen

I was banned by hopmeup on ebay because I left them neutral feedback based on the quality of the product they were selling. Dont base your opinion of A123's on what you got from them - they really are good reliable power. Not as much power as lipo, but likely much more reliable.

To do a 2S/3S set up (as 5S), you just need to remove the Flux battery wires, and insert a single pack connector - this will make the flux think it is seeing one pack. Oh, and you'll need a series wiring connector for the packs (or is that parallel???) Check Brians speed calculator page on battery wiring to verify the layout.

Ok thanks, do you find the higher internal resistance of A123 vs Lipo presents an issue?

[Unsullied_Spy]

I, for one, don't find anything wrong with your setup freeze. Those things run just fine out of the box on 4s lipo. Running in grass does put added strain on the whole system but as long as nothing was running abnormally hot it should be fine. I go WOT through grass all the time in my Muggy and it heats things up a bit but I keep the temps below my maximums (I stop at 160 on the motor, 110 at the lipos, and on my non-MMM cars 170 on the ESC). See if SMC will replace the lipos, if they do I'd continue doing what you're doing. If not then you'll need to fork over the money for some better lipos, and it might be a good idea to try what linc said and go with a 17T pinion on 5s (2s+3s). It will have more power than it does now, should run cooler, and similar top speed.

4s lipo is just fine for use in MTs and Truggies. My Muggy weighs in around 16 pounds and I've run 4s almost exclusively through it for the past year. Currently my gearing is taller than it should be (I get almost 50 MPH out of it, too fast for something this heavy) and my motor, MMM, and lipos handle it fine--the motor gets a bit hot after about 10 minutes but that's to be expected.

EDIT: If SMC won't cover you, we can give your lipos the same sendoff I gave my old Maxamps pack I just picked up my new Remington mdl. 870 Super Magnum the other day and I'm itching to try it out on something

[aqwut]

setting the LVC down to 3.5V doesn't make any sense... Like Linc said, 3.0 is a lot of safety.. I set my LVC on my PolyQuest packs down to 2.8V per cell whevever I can. But I do stop soon as the LVC kicks in or when the LVA goes off. But different packs needs different parameter. But SMC, i have never bought their packs.. and probably never will, I'm happy with the packs I have. Freeze, I do feel your pain man... "When it rain, it poors!"... I still think it's the batteries...

I have one of those power analyzers, and before I run each setup I test it out. This is what I do, I hold my setup to the ground. I push to full throttle, then down to half throttle, then back up to full throttle slowly, then back down to half, then to full throttle quickly. That is how I test my amp draw. I figure, there's no bigger load, that when the car is on the cement with a 200Lb brick behind it... Just my thoughts. I still thick it's your batteries..

[skellyo]

I've run my Flux in several situations where it should have put quite a load on my packs and I've had no issues.

I've run it across low grass on 6S with Badlands on it (53mph on GPS even).
I've run it on a track on 4S and 5S packs with LPR Crimefighters on it.
I've run it on a beach on 5S with big ass Losi 420 Sand Wedges on it.

I have not had a single heat issue with any of my power system components in any of those situations. I run the stock 20T pinion and packs are as follows:

2 X 2S 25C Enerland 5100mAh Hard Case Packs
2S + 3S 25C Thunder Power 5000mAh Packs
3S + 3S 25C Neu 4900mAh Packs

Based on my experiences, I'd just simply say ditch the SMC packs and buy something better. I've seen numerous posts on RCtech lately about puffing SMC packs or disconnected balance tap wires. That's enough for me to stay the heck away from buying them. If I were to go buy any new packs for my Flux right now, they'd be Hyperion G3's without a doubt.

[Finnster]

Originally Posted by skellyo

I've run my Flux in several situations where it should have put quite a load on my packs and I've had no issues.

I've run it across low grass on 6S with Badlands on it (53mph on GPS even).
I've run it on a track on 4S and 5S packs with LPR Crimefighters on it.
I've run it on a beach on 5S with big ass Losi 420 Sand Wedges on it.

I have not had a single heat issue with any of my power system components in any of those situations. I run the stock 20T pinion and packs are as follows:

2 X 2S 25C Enerland 5100mAh Hard Case Packs
2S + 3S 25C Thunder Power 5000mAh Packs
3S + 3S 25C Neu 4900mAh Packs

Based on my experiences, I'd just simply say ditch the SMC packs and buy something better. I've seen numerous posts on RCtech lately about puffing SMC packs or disconnected balance tap wires. That's enough for me to stay the heck away from buying them. If I were to go buy any new packs for my Flux right now, they'd be Hyperion G3's without a doubt.

I'm quite impressed if you can run 5S on the beach w/ 40s and not fry anything. If I was designing the system from the ground up, I would still use higher voltage/lower kv motor, but whatever works. Its not worth trashing the system tho.

So, it comes down to drving or batts. Unless you are a really rough driver, its gotta be the batts. Best of luck on the next set, but I would really be sure to stick to a known quantity, either Neu, Enerland, Hyperions or the cells Mike sells (the now branded CTech) In fact Mike has a hardcase 2S 5200 pack for the same price you paid for the SMCs. Sucks you are test dummy on these, hope you get some cash or replacement cells back.

[skellyo]

Originally Posted by Finnster

I'm quite impressed if you can run 5S on the beach w/ 40s and not fry anything. If I was designing the system from the ground up, I would still use higher voltage/lower kv motor, but whatever works. Its not worth trashing the system tho.

I was quite surprised myself with the temps of it. Of course when it just lights up the tires no matter the viscosity of the sand, it's not like the motor is having to pull gobs of current to get going.

[Metallover]

Think of it as the cells have to be the same brand, capacity etc., preferably with the same amount of runs. They need to be balanced together and you should be good to go. You could run a 2s and a 6s pack together if they were the same cells..