7-cell vs. 2s lipoly

[redshift]

Quit bein a wuss- lets see all those packs in series- 24S or 36S...
Lethal voltage- rubber gloves needed to connect your deans

[E-Revonut]

pedeboi - Lipo is def the way to go but don't stress your budget to much. You may want to take your $175 and first invest in a good lipo capable charger, that will charge your NiMh packs better than your current charger. Then when you get some money saved up again buy a good Lipo. There's no point in buying a cheap charger and Lipo just so you can get it all at once. Your less likely to be happy in the long run. I would highly recomend the hyperion chargers, integrated balancers and very user friendly.

As far as that stupid discharge graph goes I alos beleive it to be a bunch of BS! I think that even with the bad reputation of MaxAmps most can agree that even they outperform NiMh.

[JERRY2KONE]

WOW this is some great info/discussion on batteries. Nice to see some really good arguements on which way is better. To Lipo or not to Lipo,that is the question. Of course Lipos are better. Myabe the prices will equalize sooner or later. JayJay that graph had me splitting a gut. You always have this subtle way about you when discribing details to people who have a different spin on the subject. It would be very funny to see you and UE Robin get into a discussion of differneces of opinion. You guys are just too much. Some of the cheap Lipos out there are driving the prices down on all the rest, because the majority of people in R/C are kids who just cannot afford the exagerated inflated prices that some are charging like Maxamps. If people stop buying from them maybe they would be forced to lower their prices to. I love the American way of life and the ability to run your business any way you wnat to, but not when they are trying to take advantage of common people.

[pedeboi364]

hmmm, how about a nice LiFe cell charger? I kind like the idea of A123, not gonna blow up on me (Im not a pro like ya'll) and maybe a 6.6v rx pack?

[BrianG]

Originally Posted by pedeboi364

hmmm, how about a nice LiFe cell charger? I kind like the idea of A123, not gonna blow up on me (Im not a pro like ya'll) and maybe a 6.6v rx pack?

Any charger with A123 profile, or has programmable CC/CV threshold will work fine. Just remember that lipo are 3.7v nominal and 4.2v "peak", whereas A123s are 3.3v nominal and 3.6v "peak".

Speaking of that, a 2s A123 pack will be at 6.6v nominal, but will be 7.2v right off the charger. Despite the fact that it doesn't stay at that high voltage too long, it's still a bit too high for a RX pack IMO.

[pedeboi364]

well, at 98% doesn't the current return to normal? that was just an idea tho, would be cool. I'm thinking more along the lines of hitting my pede with a 9.9v pack. Like all the chicks say, "We'll make it fit baby." Anyways, would hobbycity be a trustable (is that a word?) retailer of A123 cells? 4 (or how ever many come in a developer kit) for $20 seems a touch low...

[BrianG]

Originally Posted by pedeboi364

well, at 98% doesn't the current return to normal?...

Not sure what you mean here. A typical lipo charger will charge at the set current until the voltage gets to 4.2v/cell. At that point, the voltage is held constant at 4.2v and the current slowly drops to a preset small value (something like 1/10 of the mAh rating).

Originally Posted by pedeboi364

...that was just an idea tho, would be cool. I'm thinking more along the lines of hitting my pede with a 9.9v pack. Like all the chicks say, "We'll make it fit baby."...

Easier to just get a 3s A123 pack if you want 9.9v. Or, just use a normal 3s lipo pack and turn down the power on the ESC (depending on the ESC used).

Originally Posted by pedeboi364

...Anyways, would hobbycity be a trustable (is that a word?) retailer of A123 cells? 4 (or how ever many come in a developer kit) for $20 seems a touch low...

I believe the word you are looking for is "trustworthy". And I'm not sure about them as I have never purchased from them, but other people seem to like them. IIRC, A123 cells are sold individually for ~$10 each. If you are getting 4 for $20, make sure they aren't the lower 1100mAh cells (or something like that).

[pedeboi364]

good points, I'll snag the link in a sec.

edit: link! http://www.hobbycity.com/hobbycity/s..._tabs_(Dev_Kit) I can't tell what mah they are, maybe that number means something BrainG?

[What's_nitro?]

That link is for a single cell, not the 4 cell developer kit. The 26650 is the size: 26mm X 65mm. That size has a capacity of 2300mAh.

[pedeboi364]

^^hmmm, then where can i get the cheapest A123 cells? What kind of batt. charger can i get to charge A123's (cheap!)

Also, my LHS is having a closing sale :( and they say to go straight for a superbrain or venom lipo charger. I can probably get a pretty good deal on the Venom, so is it a good charger?

[What's_nitro?]

I don't own any A123 stuff yet, so I don't know of a good place to buy from. I'm sure SOMEBODY on this forum does.

[JERRY2KONE]

I am not sure about the A123 cells either,as I have not used them yet. I do know that the SuperBrain 989 is a good charger and you can purchase one at a few places. If you do it right you can combine a discount code, and end up picking one up for right near $100. That is a good deal considering what you get. The 989 comes with the charger, instructions, required leads, and a 10 amp power supply all for one price. If you want I do believe that you can also pick up a balancer (LBA10) and the 989 for a fair price right here on RCM.

[pedeboi364]

thanks jerry, can you show me where i can get this "discount" you speak of? lol, btw if i end up making my own pack, can anyone show me how to make a balancing tap for it? thanks

[JERRY2KONE]

Originally Posted by pedeboi364

thanks jerry, can you show me where i can get this "discount" you speak of? lol, btw if i end up making my own pack, can anyone show me how to make a balancing tap for it? thanks

PM sent and feel free to PM me any time Sir.

[pedeboi364]

PM relpied. 977 for $50, good deal? I don't think it can charge A123's tho...