Laterilus

Hello all, these questions are for Danny or anyone else who may have the information:

First of all, I've been racing for quite sometime so I'm no stranger to all of the equipment and techniques used for our hobby, but I've finally broken down and purchased some quality matched packs (wouldn't you know, SMCs ) and I'd like to clear up a few things to get the maximum amount of quality life out of my cells. I purchased some GP 3300's at 1.18 for only 25$ a pack! wow! Gotta love those new IB cells coming out that make companies push out 'old' technology at rock bottom prices! I only race off-road so I figured GP 3300s would be more than adequate. Anywho, onto my questions:

I was blown away by the performance of the first pack I ran just to see the difference between my unmatched and matched, but I prevented myself from running another one until I got a few things straightened out. First of all, I use the ICE charger. It has been great for me so far, but one of my problems is the deltaV setting. You suggest 50 mV (sometimes 30mV... I don't know why you use different settings at times? ). I cannot set the ICE this low. I usually charge at 13mV per cell (78mV per pack) and that does the job. 3900 went into the pack! Is that normal for a new pack of 3300's? It didn't overheat... or at least for my normal standards and what I've learned. I set my thermal cutoff at 125F. It peaked at 110F after putting in 3900. Amazing. Never had a pack do that. Secondly, I'm curious about your settings for thermal cutoff as well. I see at times you mention 130-135F, but the other SMC guy (name starts with a V if I remember correctly) set his cutoff temp at 113F. Which one is it? Also, I feel that it makes more sense to peak by temperature as opposed to delta V. What is your feelings on this subject? I am by no means a battery expert and don't claim to be, I'm just going by my gut feeling and reasoning (I'd consider myself better than the average 'gut feeling' as I'm an engineer ). It seems to me that temperature would make the most sense since the reversible chemical reaction being forced in the opposite direction (charging) would start producing heat once the reaction was completed (full charge). No where for the energy to go, so it releases heat. Checking the temps of my batteries during charging strengthens my thought process as my batteries always peak when the temperature rises 15 degrees F within one minute! It only makes sense the reaction has completed and now it is simply releasing that excess energy as heat. Makes sense, but I'm no expert. I bring this up because it seems odd to me the ICE charger false peaks if I set the delta V per SMC instructions. I have to set it high, then usually rely on the temperature cut off to peak the battery.

Anyways, that's it for now. I'm sure I'll have more questions along the way as I read more and more of the pages in this thread. Any help to my questions would be appreciated.

Danny/SMC

iTrader: (2)

Maybe somebody can give you the answers as I have to leave for a my pool league. If no one has answered I will when I get back.

Unregistered

In my opinion, you can set your charger to whatever cutoff voltage that you find works well for you. Always keep an eye on the pack or use the temp cutoff as a safety factor. 120 degrees is pretty safe for GP 3300's and should keep you from overcharging too much. I set mmy peak detect as low as I can and still get the cells warm at the end of the charge.

I would never use a set temp for ending your charge because there are so many variables that can change the temp the cells are at when the pack actually peaks (it is an excellent safety device though). Charging a battery with some charge already in it, or on a cold day, or at a low current could let you overcharge the cells without getting them hot. The cell manufacturers build some safety margin into the cells to allow for overcharging but any long overcharge is bad for the cell regardless of what temp the cell is at. On the flip side, you could dump a pack (on a zero 30) and get it a little warm. This extra heat could make the temp hit the cutoff before the cell is completely charged and you'll get less capacity. Undercharging isn't necessarily a bad thing but it's not very good for racing either.

Danny/SMC

iTrader: (2)

On the Duratrax site it says the ICE is adjustable from 0-25mv so you should be able to set it lower. Make sure you get it around 50mv - 70 mv for the entire pack. The reason why reccomend different mv settings is because of the room temperature. When it's hot you use a lower setting when it's cool you use a higher setting.

I'm not aware of the temp reading of the ICE but I know with a Raytek temp gun our GP3300 packs would run there best in the 135-145 range. Typically this temperature would be achieved by using 50mv(.05) on a Competition ELectronics charger

Follow these guidelines and you should be in good shape.

eskiserkan

Hello . My charger has a delta peak property and it is setting the peak value automatically . Is this creates a problem for your IB3800 battery packs??

Danny/SMC

iTrader: (2)

The peak detect isn't adjustable ? You need to know what the peak detect is set at. Charge a pack and when the voltage stops climbing at the end of the charge and goes back count how many .01 of a volt it comes down before it shuts down.

Lets say it stops at 9.20 volts and then drops to 9.17 that would mean the peak detect is 30mv(.03)..

mike ivy

iTrader: (51)

Hey Danny,

Is it Ok to use the Trinity Dyna pulse to discharge IB 3800's after racing Im currently running 4-cell 12th Mod roadcourse or would you recomend another way to discharge them after the race.

Danny/SMC

iTrader: (2)

I saw you asked Mike Blackstock about this follow what he does he has allot of track time and will know what works or doesn't.

eskiserkan

Hello Danny . I will observe the peak settings in my charger . If the peak result will be lower than or higher than 0.30 mv what is the possible outcomes for charging the SMC pack at this settings??

Thank you .

MOJO

iTrader: (1)

Hey Danny; Well the first batch of 3800`s I got I was running 3 runs a day and this did drop the run time a little but still well over 5 min in them each use! Just got more and plan on taking better care of them. Only running the new batch once a day dicharging then tray em till next day. Should I be putting them on the 030 tray before charging after allready doing this the day before? Thanks, tell Brian hey for me, Hope to see you guys at my track this summer!

SOuthernFRIED

iTrader: (21)

WIll SMC start matching the 4200's?

gulio

iTrader: (32)

couldn't resist to interrupt,

The charger will shut off a few seconds early or a few seconds later than if it was 30 mv. If it is non-adjustable and auto-matic it will probably be a bit late.

Danny/SMC

iTrader: (2)

You should bring them down to .90 per cell using a 30/35 amp rate then leave them alone. The next time you go to run them place them on the 0-30 for 1 minute then start charging them. This has given very good results.

Danny/SMC

iTrader: (2)

If the peak detect is higher than .03(30mv) then it will overcharge the packs and this will not be good for them. A bit lower is fine as we mostly use .02(20mv)

Danny/SMC

iTrader: (2)

Yes we expect to have the first batch matched up by the end of December so expect to see them in stores around the second week of January.

SOuthernFRIED

iTrader: (21)

Thank's for the reply.

aus jd 2703

iTrader: (5)

hey when should i dicharge my gp3700 to o.ov?? and when should i leave them at .9v?? should i invest in some discharge racks if so what kind so far i only have 4 packs that i use but i want them to last and so far they only take on 3000mah after discharge to .9v what am i doing wrong also does a hot ambient tempreture mean i should use a fan to cool my batteries as they charge its just in australia its started to heat up and my batteries are at 32'c (about 90'f) and they hit 50'c 122'f at about 2900mah i use an ice with 5 amps charge 10 amp discharge and .4mv deltapeak please help me before i kill my new batteries

MarkBrown

iTrader: (9)

Danny, you mentioned in an earlier post that IB is now producing 3600s using the same techniques they developed for the 3800.

Are these new 3600s available now? Is there any way to tell the newer 3600s from the older ones?

Thanks,

--mark

Hammer1

I have been hearing alot of conflicting suggestions as to what to set the peak detection at for the 3800's.

I just picked up a set to replace my 3300's and would like to properly care for them, any suggestions??

Danny/SMC

iTrader: (2)

You need to use 40-50mv for the entire pack.

Do not blow any air on the pack as it will not charge properly.

After a race discharge down to .90 per cell. The prior to charging the pack again place it on a discharge tray. The Integy 0-30 works well.

Danny/SMC

iTrader: (2)

There is no real way to know which ones are improved. Were currently sold out on IB3600s. ProMatch has the latest IB3600s.

Danny/SMC

iTrader: (2)

Follow what we reccomend on our website under the charging section.

If you have any questions after reading it feel free to ask.

Hammer1

Very helpful!! Thanks for the info....

Formula1fan

What do you think about the Dyna pulse and spintec dischargers?

_nick_

were can i find cheap loose smc cells? 3300-3800

kukkiyukkuk

yes I am also looking for some loose smc cells either 8 or 4 cells

Team Duratrax

http://www.stormerhobbies.com/cgi-bi...umb=on&smode=0

_nick_

no, i want liek bulk loose. THanks ne way.

minidriver

iTrader: (2)

Danny:

I purchased two SMC 4 cell IB3800 packs for 1/12th scale stock motor racing about 2 months ago. Purchased same day, built identically, used exactly identically. Virtually identical numbers on the cells of of 440 secs, 1.205 V on each pack. Each used once a week for a month, then not used for a month, then used them both this week. In between each week during that month of racing they were left with the remaining charge after an 8 minute race, trayed the next week just before once again charging and running. No problems with sufficient runtime from either pack during that first month of racing.

Both were killer packs (voltage, punch) in the race this week, but one saw me through the 8 minute qualifier fine, the other was great until 7:40 into the main race and dumped like a rock. As the motor was the same, same rollout, for the qualifier and the main I wondered what happened, as i didn't think I got a false peak, and I think I recall both packs taking about a 4000mah charge. I Took them home and put them on Novak tray to .9V, and then cycled them on T35 at 30 amps discharge (6 amp charge rate, .03 delta peak, my typical charge profile).

Cycle numbers for the packs now are: for the qualifier race pack, 440 secs, 4.78 V pack average, low IR #s. For the main race pack that dumped prematurely, 400 secs, a killer 4.84 v, also low ir numbers. In other words, this second pack is still really a killer voltage wise, but it's no good to me if it dumps at 400 secs.

Any sugestions for reviving that pack back up to numbers closer to 440 secs. I'm willing to trade average voltage for run time. Reduce the charge rate to 5 amp? Cycle them a few times? Tray them differently?

Danny/SMC

iTrader: (2)

Unfortunately it seems like one of the cells in your second pack has shorted out. After you discharge the pack on your T35 place it on a tray and you should see one of the lights shutdown almost immediately and they other 3 stay on for awhile. This will indicate which cell has an internal short.