[LithiumaniacsEVRacing]

I was ready to order my Headway Batteries tomorrow and happen to be snooping on NEDRA's Yahoo board and seen Johnny Metric's Fiero Build and his packs. He is using:

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10090

What is the forums opinion on using these packs to build a larger pack? He seems to love his battery pack.

 

[LithiumaniacsEVRacing]

 

[LithiumaniacsEVRacing]

 

[ewert]

Horribly expensive compared to the 45-90C nanotech Turnigy on the same site ...

The nanotech Turnigy has been mentioned a few times here now, on endless-sphere tests have been done on them (they melt faces).

If I were doing a dragster, then http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14617 times 50 for 100s5p or 370V 25Ah, 90C max burst for 2350 amps to melt your controller and/or motor ...

I think on endless-sphere one of the battery testers said he had pulled 200C from it ... melt faces, yep. =P

 

[LithiumaniacsEVRacing]

Okay, I am very interested and now looking for more feedback. Can these "pre-built packs" be connected in parallel in each battery box to up the AH and then can each battery box be connected in series to up the voltage? and for my last question, can the BMS work with theses pree-built packs?

oops, another question, the packs used in John Metric system have a XF2 marked on them, but the batteries on the Hobby King's website only have XF marked on the pack, same volts and amps?

Horribly expensive compared to the 45-90C nanotech Turnigy on the same site ...

The nanotech Turnigy has been mentioned a few times here now, on endless-sphere tests have been done on them (they melt faces).

If I were doing a dragster, then http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14617 times 50 for 100s5p or 370V 25Ah, 90C max burst for 2350 amps to melt your controller and/or motor ...

I think on endless-sphere one of the battery testers said he had pulled 200C from it ... melt faces, yep. =P

 

[Frank]

I understand that the batteries he is using have not been released yet.

 

[toddshotrods]

Dude, did you fall asleep in class?! LiPo was suggested in one of your other threads.

• The advantages are availability, cost (compared to something like Kokam), ease of construction (compared to thousands of small cylindrical cells).
• The disadvantages are less range, and probably a shorter cycle life.

I'm thinking hard about them since seeing the info that was posted in your other thread. At least for a starter pack. I stated that it that thread, but you never really seemed to respond to the idea of LiPo, so everyone probably figured you weren't interested. For a dedicated drag car, they make perfect sense because range isn't really an issue. IIRC, he was talking about something like 25-miles of range on the Yahoo Group?!

 

[ewert]

Okay, I am very interested and now looking for more feedback. Can these "pre-built packs" be connected in parallel in each battery box to up the AH and then can each battery box be connected in series to up the voltage? and for my last question, can the BMS work with theses pree-built packs?

Connecting for power can of course be done however one wants. Probably series+parallel rather than parallel+series to keep the high amp connections lower.

They have prebuilt balancing plugs (that jst-xh thingy). The guys on endless-sphere are doing R&D on boards for balancing multiple packs from a big charger, as far as I can recall. Anyways, they have much more info on these packs and how to use them in big packs instead of just singles like the RC guys use. I'd really suggest researching their forum for the balancing thing. I don't recall exactly what the end result currently is in there.

 

[LithiumaniacsEVRacing]

Dude, me falling asleep with one of your long posts is a possibility! Only kidding.
I do remember you guys posting about LiPo's. but did not know they produced and sold such a large configuration, I thought they were all much smaller.

Dude, did you fall asleep in class?! LiPo was suggested in one of your other threads.

• The advantages are availability, cost (compared to something like Kokam), ease of construction (compared to thousands of small cylindrical cells).
• The disadvantages are less range, and probably a shorter cycle life.

I'm thinking hard about them since seeing the info that was posted in your other thread. At least for a starter pack. I stated that it that thread, but you never really seemed to respond to the idea of LiPo, so everyone probably figured you weren't interested. For a dedicated drag car, they make perfect sense because range isn't really an issue. IIRC, he was talking about something like 25-miles of range on the Yahoo Group?!

 

[LithiumaniacsEVRacing]

That is a possibility, but I see no difference in packs, except the "XF" on the Hobby King site, and the XF2 on his packs, what the difference? All the specs he posted is the same?

I understand that the batteries he is using have not been released yet.

 

[LithiumaniacsEVRacing]

From what I have read last night, Turnigy has a bad rep with their cells.

Horribly expensive compared to the 45-90C nanotech Turnigy on the same site ...

The nanotech Turnigy has been mentioned a few times here now, on endless-sphere tests have been done on them (they melt faces).

If I were doing a dragster, then http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14617 times 50 for 100s5p or 370V 25Ah, 90C max burst for 2350 amps to melt your controller and/or motor ...

I think on endless-sphere one of the battery testers said he had pulled 200C from it ... melt faces, yep. =P

 

[toddshotrods]

Dude, me falling asleep with one of your long posts is a possibility! Only kidding.
I do remember you guys posting about LiPo's. but did not know they produced and sold such a large configuration, I thought they were all much smaller.

I didn't post about them wise guy, I was reading and learning right along with you. My main responses to the idea of LiPo were along the lines of, "hmmm, I might..." They have been discussed before on this forum but never with the specifics that were covered in that thread. There are links to the testing on the ES forums too. That's why I said you must have fallen alseep in class, because it was fascinating info. I think that exact Turnigy pack that ewert linked is in the other thread as well, or at least I have a link to it in my favorites as a result of that thread.

FYI, being longwinded is my "gift" in life.

Now, PAY ATTENTION!!!

 

[LithiumaniacsEVRacing]

Can't you take a JOKE?

Now Smile!

I didn't post about them wise guy, I was reading and learning right along with you. My main responses to the idea of LiPo were along the lines of, "hmmm, I might..." They have been discussed before on this forum but never with the specifics that were covered in that thread. There are links to the testing on the ES forums too. That's why I said you must have fallen alseep in class, because it was fascinating info. I think that exact Turnigy pack that ewert linked is in the other thread as well, or at least I have a link to it in my favorites as a result of that thread.

FYI, being longwinded is my "gift" in life.

Now, PAY ATTENTION!!!

 

[ewert]

From what I have read last night, Turnigy has a bad rep with their cells.

Well I have been following endless-sphere for over a year, and I haven't really seen much bad rep about new Turnigys during that time. I recall the older LiPo were much more hazardous etc., but the new ones, especially the nanotech versions, seem pretty good. There is just no way anything beats that kW/$ really, I mean it's pennies for the whole 2000 amps compared to what Kokam/A123 cost, which can pull that much punch with comparable weight ...

 

[LithiumaniacsEVRacing]

Okay, I will take a better look. I read on some RV forums that cells were lower after little use. Some kept good when some went bad.

Well I have been following endless-sphere for over a year, and I haven't really seen much bad rep about new Turnigys during that time. I recall the older LiPo were much more hazardous etc., but the new ones, especially the nanotech versions, seem pretty good. There is just no way anything beats that kW/$ really, I mean it's pennies for the whole 2000 amps compared to what Kokam/A123 cost, which can pull that much punch with comparable weight ...

 

[Jozzer]

You need to buy extra and test each and match before assembly, then you will end up with a very strong pack. I had some 5 bikes racing TTXGP with them this year, and not a single failure in use.

I too told you before this was the ONLY way to go for a dragster..

Turnigy 20C packs are sufficient IMO.

 

[LithiumaniacsEVRacing]

Thanks! I am glad I finally seen the light!

You need to buy extra and test each and match before assembly, then you will end up with a very strong pack. I had some 5 bikes racing TTXGP with them this year, and not a single failure in use.

I too told you before this was the ONLY way to go for a dragster..

Turnigy 20C packs are sufficient IMO.

 

[ewert]

The 20C ones though are "normal" packs, dunno if they would be hurt more by this kind of use (massive burst). I mean you don't really want to go with 20C and build a pack twice the size if you can go 40C ... or triple if you go 60C. =P I guess 60C and over is pushing it ... and of course you only need the full C at the very final part of the run when you need the volts too to max out your controller/motor.

I made a spreadsheet once of the $/kWh of the packs, but haven't updated it since the nanotech stuff, so can't say right away which one is a good price though.

 

[toddshotrods]

Go with the highest c-rate available, so you don't limit your car's ability. If Ron succeeds in his goals, you can't judge his needs by what you've seen the average EV drag race vehicle do/need. If he's utilizing that chassis, he will be pulling insane current levels off the line. Also, the max current will be pulled off the line, and kind of tapers off down the track. It's not going to pull max current and voltage at the same time. Current is torque to get moving, voltage is rpm to keep moving - oversimplified to make the point.

 

[rwaudio]

Go with the highest c-rate available, so you don't limit your car's ability. If Ron succeeds in his goals, you can't judge his needs by what you've seen the average EV drag race vehicle do/need. If he's utilizing that chassis, he will be pulling insane current levels off the line. Also, the max current will be pulled off the line, and kind of tapers off down the track. It's not going to pull max current and voltage at the same time. Current is torque to get moving, voltage is rpm to keep moving - oversimplified to make the point.

I know you know your stuff todd, but don't confuse battery current and motor current.

At launch battery current will be very low since the controller is power in - power out.
IE 2000A and 20-50v to the motor on the very early part of the track
This works out to only 114-285A from the batteries assuming 350v