tomjasz
1 GW
Sometimes I really miss Usenet and the good old fashioned, PLONK.
I refuse to buy from Hobby King
spinningmagnets said:I have moved away from LiPo once the Samsung 25R and 30Q became available,
I am a big fan of 14S, using 18650's, and...a fairly compact 5P string of 25R's will provide 100A from a fairly small package. Recently, Luke has been posting a preference for considering lower voltages and raising the amps.
My experience with Turnigy and Zippy LiPo is that they are equal in performance, life cycle, and reliability (the experience of others might be different, YMMV). Luna Cycle has 18650-cell packs from the 25R, 30Q cells, reliable, safe, etc. [full disclosure: I write for electricbike.com, which is owned by the same guy as the Luna store, so don't trust anything I say], if you want the MJ1 cell to build your own pack, they can be found at Wake and Vape.
nutspecial said:Some good points and comments I could quote but glad you rabble rousers calmed down
I am using turnigy 5.8 and they are very reliable @ about 1/4 the c-rate. Seemed like the best c-rate and ah for the price at the time. Out of a combo of 6s and 4s, I do have 2 cells of 16 in the 4s that will need retired early. Although it's only the 4s which were bought later in the year and had lower balance consistency out of box, I'm chalking it up to newb mistakes such as pretty low pack overdischarge and also trying to draw 70a and charge @15a a single 5.8 string of 30c (so half c on draw and 3c charge). Since I've paralleled to 11.6ah. I think I will prob do the same next time as it works for my build pref. As others have noted, bulk charge most of the time, and occasionally balance.
Electricgod, kinda a good name, maybe Luke's mad he didn't think of it? (jk )
What are you planning on doing with the 8ah cells when they come (config and pack layout)? Draw requirements? At least they'll be assumably fresh stock. If availability is holding you up could you cancel/switch to another? What would it be? Do a123 pouches work for what you want? Do you think 'sleeping tazmanian devil' is more appropriate simile for a lipo cell?
nutspecial said:That's cool macribs. . . would love to see your build sometime. Did I miss it?
e-god, hopefully abbrev are cool with you occasionally? I'm wondering how many cells are pictured there?
(Nice ride btw!)
Something like 14s 4p? And you want 20s 4p? Yes, if I can safely get 70a from my 20s 2p 5.8 30c you can def get 24a++ outa 20s4p 8.0 10c. Safely that would be 80a @ 1/4c. Lots of range. Very low draw on battery. Could handle a 30a bulkcharger. . . . What about increased speed from 20s voltage though? Room for 80cells?
If not buying hk where else is there? What about a123 prismatic pouch I hear about?
nutspecial said:Well based on a huge speed increase going to 20s and the limited space to increase battery by 40%, I'm thinking 20s 3p might be an issue.
I'd not heard of 3c, although that would be a good place to run the multistar 10c packs. If you're happy with speed perhaps fresh packs of 12-14s 10c with 4th parallel will work, or 3p of their 16ah packs? I'd personally love to try the 50-70c stuff, but besides the expense it's an obvious risk they'd be that much more volatile/incendiary and be more sensitive to aging
PS/ Kudos macribs, there's nothing like methodical patience (i'm told ) and you've built an impressive knowledge base.
Allex said:Lipo - for those who still stuck in the early 2010s, who loves a rats nest, who loves to dedicate free time for balancing, who loves heavy, bulky and swallowing things
The only thing they are good for is R/C toys OR a special dragrace machine where you need extreme C rates in a small package.
Allex said:Lipo - for those who still stuck in the early 2010s, who loves a rats nest, who loves to dedicate free time for balancing, who loves heavy, bulky and swallowing things
The only thing they are good for is R/C toys OR a special dragrace machine where you need extreme C rates in a small package.
Ykick said:Allex said:Lipo - for those who still stuck in the early 2010s, who loves a rats nest, who loves to dedicate free time for balancing, who loves heavy, bulky and swallowing things
The only thing they are good for is R/C toys OR a special dragrace machine where you need extreme C rates in a small package.
Yeah, we're just dregs of society...
ElectricGod said:OOH! Can I be a societal dregg too?! HAHAHA.
So...since LIPO's are so awful, I guess you are saying that 18650's are better? I guess I'm just stuck in the dark ages. ;P
Ohbse said:ElectricGod said:OOH! Can I be a societal dregg too?! HAHAHA.
So...since LIPO's are so awful, I guess you are saying that 18650's are better? I guess I'm just stuck in the dark ages. ;P
That is the implication, yes
For anybody late to this party, you seriously should go 18650's for almost all requirements if you're building anything other than a toy. I don't mean that in a derogatory way, just that the time expense, complexity and risk that comes with Lipo packs are not something I would recommend on an EV that you rely on or use on a daily basis. I've built packs from lipo, used them on a daily basis for >1 year and literally worn out the connectors from reconfiguring the pack to charge, balance etc. There is thankfully now a better option
Spot welding is a problem largely solved with the advent of battery powered switched mosfet welders - I built my one before theJP w elder was available for <$100 and have done many thousands of welds. The latest generation of high power cells are exceptionally energy dense while delivering a serious punch. Lifetime cost is lower than all lipo except possibly for the cheap hardcases on special, however you're going to invest substantially more time maintaining a sizable pack assembled from those.
All that being said, I'm looking to pull the pin on buying some Turnigy Nano-tech A-spec G2's to parallel up with a bunch of Samsung 30q's haha
Despite ElectricGod's highly aspirational username, he's not the highest authority on batteries