Joined: 20 Jul 2004
Posts: 2523
Location: Victoria
lol maby its the shit dick smith solder im using would not surprise me nothing they sell is quality. _________________ Tim Team Reaper.
Tue Dec 23, 2008 7:09 pm
timmeh Experienced Roboteer
Joined: 20 Jul 2004
Posts: 2523
Location: Victoria
hmm went from 2mm copper wirerods to copper braid dosent seem to pop off now but it dosent take much to pull them off any shock would prob bust them.
I know braid has flex but still the bars should not have poped off that easy. _________________ Tim Team Reaper.
Tue Dec 23, 2008 8:02 pm
andrew
Joined: 16 Jun 2004
Posts: 3110
Location: Castle Hill, Sydney. N.S.W
weird man, on the few packs i made dremeling the ends rough and using 12 g wire seemed to work ok, how odd
worst case look into solderless tube packs _________________ Andrew Welch, Team Unconventional Robotics
Tue Dec 23, 2008 10:23 pm
Valen Experienced Roboteer
Joined: 07 Jul 2004
Posts: 4436
Location: Sydney
silver solder has a *much* higher melting point than normal stuff.
tin/lead is probably the best bet for that kind of things, but your best off not soldering the cells if you can avoid it. _________________ Mechanical engineers build weapons, civil engineers build targets
Tue Dec 23, 2008 10:23 pm
timmeh Experienced Roboteer
Joined: 20 Jul 2004
Posts: 2523
Location: Victoria
where do you buy tube packs? _________________ Tim Team Reaper.
Wed Dec 24, 2008 11:18 am
andrew
Joined: 16 Jun 2004
Posts: 3110
Location: Castle Hill, Sydney. N.S.W
basically you put the heatshrink over the bare cells which comes with, apply some funky conductive sludge to the end of the cells which also comes with the kit, slide em into the tubes and clamp the whole lot together with some very thin threaded rod and nuts.
Only issue is balancing the cells would have to be done after every event and mid event balancing would be hard unless you make up some jig to put every single cell in
My plan is to make up a lil jig and before and after the event i can balance the cells easily then re-assemble the packs. _________________ Andrew Welch, Team Unconventional Robotics
Wed Dec 24, 2008 12:50 pm
Glen Experienced Roboteer
Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect
theres a few mods out there where people have just soldered some really thin sheet to the outside of the cells and ran the balancer wires out the middle. was gunna do that myself except i kept physically breaking the packs _________________ www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz
Wed Dec 24, 2008 1:04 pm
timmeh Experienced Roboteer
Joined: 20 Jul 2004
Posts: 2523
Location: Victoria
What is the lowest discharge voltage for a123 cells?
Looking for a cutoff jigy to hook up to the reciever. _________________ Tim Team Reaper.
Mon Dec 29, 2008 8:36 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Did you read the fine print about the Liposhield only working with single direction ESCs? they won't help you if you use reversing controllers
Mon Dec 29, 2008 9:31 pm
timmeh Experienced Roboteer
Joined: 20 Jul 2004
Posts: 2523
Location: Victoria
ahhh lol
Hmm maby something can be made. _________________ Tim Team Reaper.
Mon Dec 29, 2008 9:32 pm
Valen Experienced Roboteer
Joined: 07 Jul 2004
Posts: 4436
Location: Sydney
bah don't worry about it.
you probably wont flatten an A123 pack anyway _________________ Mechanical engineers build weapons, civil engineers build targets
Mon Dec 29, 2008 11:13 pm
Glen Experienced Roboteer
Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect
anything under 2.9v and mine seem to never take a full charge again. i think thats the problem when i had them powering the dewalts, it was just discharging them way too far and theyd go out of balance exceptionally quick.
you can get lipoly wireless devices at united hobbies that plug into the balancer port on the battery and transmit back to a little box you put on the transmitter and it beeps when the battery is too flat.
Joined: 20 Jul 2004
Posts: 2523
Location: Victoria
will be running large brushless motor and two large drill motors. _________________ Tim Team Reaper.
Tue Dec 30, 2008 8:01 am
Rotwang Experienced Roboteer
Joined: 15 Jun 2004
Posts: 1589
Location: Vic
Well the $ per cell equation seems to has shifted in favor of LiPo’s by the look of it.
Only thing that concerns me is how fast can you get away with charging LiPo’s. _________________ Satisfaction is proportional to effort and results.
Tue Dec 30, 2008 11:27 am
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Most manufacturers recommend 1C charging rate. If you know about how discharged the packs are, you can get away with a 2C rate to begin with. A few of the latest technology packs are OK for 5C. I find the most important thing is to cool the packs down to room temp. before recharging.
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