View Full Version : Need help,what to look for when charging batts.
yuk17bandit 12-12-2005, 06:01 AM was woundering. i have a pit bull charger v1.? how can i tell what pack is better than the other by the final charge #. what means what?
also what should i be charging at . i run stock oval , i have 3300 matched 4 cell packs. i have no problem with run time . looking for volts. whats the best way.?
how do i keep them in best shape. after each run i discharge them on a trinity real time conditioner. is there a better way i should be doing it.
i've done some reserch but don't realy understand it. so if some one wouldent mind helpin a newbie out , thanks .
my first race about 8 weeks ago i had about 2/3 of many laps as the leader did. and with help to fellow r/c people that take time to help out , this week i TQ and won the A main by only .500 of a sec. , but is was a awsome feeling. MY THANKS TO YOU ALL
DynoMoHum 12-12-2005, 09:30 AM First off... I hate to tell you this, but the 3300 cells are like yesterdays news... and are not going to be really competitive if others are using newer 3800 (or now 4200) cells.
I'm not that firmilar with the Pitbull... so I'm not totaly sure what numbers it gives during a charge...
Typicaly a charger will show voltage, as measured across the pack that's being charged. Contrary to what may seem to make sense, higher voltage during charge, does NOT mean your packs will have a higher voltage during discharge/use. Basicly the charger is putting a constant current through the cells, and the voltage being read is somewhat related to the internal resistance of the cells... In many situations, good packs will show a lower voltage while being charged then bad packs do... but this is not gaurnteeed either...
Basicly, there is very little knowlege to be gained from watching the charger's numbers as your charging. You really need to measure voltage and internal resistance of a pack as it's being discharged, to get a good idea of how well it's going to proform...
Fl Flash 12-12-2005, 10:37 AM Congrats on the A-main win!! Bad news is it sounds like your hooked LOL ! So am I :) Heres what I do, I budget to buy 2 of the best matched battery packs out there every 2-3 months ( whatever matcher you prefer theres several good ones Pro Match,SMC,Power Push,Pole Position). No more than 2 packs at a time, you never know when a "better" battery will come out and you dont want to spend 200 bucks then the next week have the second best batterys. Then ask the Matcher how to best charge and maintain the batteries you have bought from them, most have websites and all will help you!
In the meantime those GP3300s are good packs they have won a pile of races! I still run them for practice and weekly races.
GP3300s I unshort then charge at 6.0 amps with 100 second lockout and .03 drop if they get done charging and sit for more than five minutes before my next race I repeak them at 6.0 amps with no lockout and a .03 drop...Race them ...discharge at 30 amps...tray them to 0 volts then deadshort them. Deadshorting will increase voltage but hurt runtime.
Have Fun
DJ1978 12-14-2005, 11:35 AM Every one has their opinion on battery care.... and what batteries are best.
No offense to DynoMoHum... 3300's are not yesterdays news...there is nothing wrong with good 3300 packs. I have quite a few packs that over one year old and still taking more than 3300 Mh when charging. They are excellent race packs.
Battery care is crutial and yet Nickle Metal batteries are very durable and can be run over and over.
I tray my batteries once or twice a month... Charge at 7 amps. Discharge for 30 seconds at 20 amps before charging the day before a race and peak just before the race. I run the same battery all day!!
With the capacity the new batteries have... 3300, 3600, 3800 or more, we no longer worry about run time.. they have more than enough capacity for a 5 min race. Those higher numbers are capacity.. so they will keep you running longer...
The fact that you won the A shows it is not the number on the battery pack... but the set up, the motor car and driving skill. Keep up the good work and have fun!!
Dan
Bob Wright 12-14-2005, 08:01 PM bandit come see me or talk to Corey on Saturday if your up at the Triclone.
Stratus54 12-17-2005, 10:39 PM Every one has their opinion on battery care.... and what batteries are best.
No offense to DynoMoHum... 3300's are not yesterdays news...there is nothing wrong with good 3300 packs.
Dan
No offense Dan but 3300's ARE yesterdays news... use them for practice until they finally die... unless your in a beginner/sportsman class. I know someone will post about how they won the A in a race full of sponsored guys (who were all running 3800's) with their 2 year old 3300's... bla bla bla... but face the facts the IR and the voltage curve of a top shelf 38800 can not be touched with any 3300 :)
Trixter 12-18-2005, 10:27 AM So with all of this good news about 3800's, what about 4200's that my favorite matcher is working on as we speak. Will that make 3800's yesterdays news too?
Just to keep the gears of your think-engine turning.
Stratus54 12-18-2005, 10:19 PM nope... according to SMC they run the same as 3800's with 30 seconds more run time... so they should only affect mod racing as the 3800's have plenty of run time
Stratus54 thats what everybody said when the 2000 came out, then the 2400,Then we jumped to 3000 and of course the only racers who needed those were MOD too. Then the cycle continued 3300, 3600, 3700, now 3800, and if you believe the 4200's are only good for MOD...then I have some swampland in south georgia for sale.
Wade
I do what Fl Flash suggests.
Stratus54 12-20-2005, 03:54 AM Well I have been looking for some good real estate :)
I was going by the post from Danny (SMC) that said lap times were the same and the 4200's just had 30 seconds more run time...
I know when I finished my heat last week (19 turn foam TC, 3800's) I discharged the pack on my GFX and I noticed the voltage stayed above 7 volts for 37 seconds at a 30 amp discharge... so I was nowhere near the slow end of the curve... I doubt another 30 seconds of run time would make a noticeable difference.
the thing with the runtime for stock and 19T guys, is your staying further back in the voltage curve,which equates to less drop off at the end of the run,like now with the 38's we are seeing very little drop off in lap times,so in order to know if there is a real difference you would need to look at a graph of a 38 and a 42 and see where the voltage curve is for each pack at 240 secs,this will tell you if there is any advantage.Also the IR will make a big difference,this where the 38's are heads above the 33's.
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