Hey guys, I did a search but didnt have much luck finding an answer. Our local track is going to start using the SMC 1 cell 4000 25c lipos. My questions are:
1. What is a good rate to charge at? I am looking more for battery longevity and safety than squeezing every ounce performance wise out of it. Im just a weekend warrior - not a pro.
2. What is a good voltage for storage? I usually race every week but sometimes their may be two or three weeks in between.

Thank you in advance,
Mike Moore

Safe charge is about 6 ot 7 amps. Top racers charge at 10 amps.

For storage you can just throw it in the bag after a 4 min run. It will not drop off enough to hurt it for months.

Thanks J-Dub for the quick reply. I didnt know if I had to be more exact with everything but its looking as if the lipos are easier to take care of then nm's.

Yeah, they really are. I was charging mine this weekend with the pulsar 3 at 7 amps. It seemed to work fine. It is about a year old now, and I had no problems with it even though it sat all summer. Gotta love not having dead cells after 2 or 3 weeks of use!!

4000-25c is old technolgy. SMC is no doubt looking at 5000-10c technolgy. Open your wallets boys, SMC LOVES YOU!!

from TQ Cells website:

Recommended charge settings

You've purchased a high quality battery pack ... make sure it delivers to its full capacity! Charge the battery pack using a high quality charger and set your charger using the following recommended settings.

Charge amperage: CC/CV 2C ïclick! Example : 1s Lipo 4000mAh ... 2C = 2 X Lipo mAh = 8000mAh = 8A



Charge cut-off: 1S or 1cell

Recommended discharge settings

Discharge amperage: Linear 35A

Discharge cutoff voltage: 1cell (3.0V)

"Race Day" recommended procedure

Here are step by step, the recommended charge/discharge procedures that you should follow while at the race track.

All you need is 1 battery pack! Isn't Lipo racing GREAT!!!

Just before charging the battery pack for the first run, using a discharger unit such as the CE GFX, discharge the 1s Lipo battery pack down to 3V
Then, charge at 8A (in Lipo 1cell mode)
Once the charging cycle has completed, no extra step are required before your run
Just before re-charging the battery pack for the second run, again using a discharger unit such as the CE GFX, discharge the 1s Lipo battery pack down to 3V
Then, charge at 8A (in Lipo 1cell mode)
Etc.

4000-25c is old technolgy. SMC is no doubt looking at 5000-10c technolgy. Open your wallets boys, SMC LOVES YOU!!

don't you mean 5000-50c....do the research.:tongue:

don't you mean 5000-50c....do the research.:tongue:

I thought too that 10C would be the Old School! :rolleyes:

4000-25c is old technolgy. SMC is no doubt looking at 5000-10c technolgy. Open your wallets boys, SMC LOVES YOU!!

not this year!!!! rules have been made!!!:thumbsup:

4000-25c is old technolgy. SMC is no doubt looking at 5000-10c technolgy. Open your wallets boys, SMC LOVES YOU!!

amazing :rolleyes::freak:

Thanks Outlaw, I will be using a Multiplex charger with the settings you gave me.
If I may ask another question though, why do you need to discharge the battery before you recharge it?
Sorry for the stupid questions guys, Ive been racing since '85 but this is my first go around with lipos.

discharging the pack at 35 amps will warm up the pack and supposedly aid on recharge,plus the batt is still warm for race time

Yeah, that was the reason. Now though if the pack is 5 degrees over the track temp you are DQ'ed, so dont worry about the discharge part.

Yeah, that was the reason. Now though if the pack is 5 degrees over the track temp you are DQ'ed, so dont worry about the discharge part.

Discharging the pack just before charging will not have you DQ ... pack will cool down to room temp before the completion of the charging process.

Steve.
TQ Cells

Discharging the pack just before charging will not have you DQ ... pack will cool down to room temp before the completion of the charging process.

Steve.
TQ Cells
Then why is discharging recommended before charging?

uhm,Thanks so much 4 sharing with us,bros :-)

Then why is discharging recommended before charging?
personal prefrence.. you really dont have to...just repeak after your race, you'll be fine and still be competitive....mainly this is done is to put heat into the battery but you can not heat the batts or at least have them over 5 deg room temp so there is no performance gain imo by discharging, so cycling lipos is not really need, there not like our counter part nimh's. The only reason you would cycle a lipo is to get number's from it other than that no need.. just charge and go racing and have fun!!!

ya. but its not legal. check the rules!

I charge my SMC 4000Mah 25C on a Checkpoint 1030, Lipo mode 6.5 amps...Battery is performs same as day 1!

Question for you guys: Would a gfx with the lipo feature be a good, better or best choice to charge 1 cell? thanks

It is fine to charge the 1C stuff. IMO the best is the Pulsar 3, but the GFX is a close 2nd. The main reason is the GFX is so big, and you can adjust the voltage on the Pulsar 3 to reflect the track volt meter during tech.

I have the Pulsar 3 and it works great. Only thing is if you want to cycle your packs, the GFX or 35 Turbo will work the best. Pulsar 3 can only discharge up to 10 amps.

SMC, Recommends only discharging for storage. charge, re peak, then discharge to 3.3 volts per cell when not in use.

SMC, Recommends only discharging for storage. charge, re peak, then discharge to 3.3 volts per cell when not in use.

Hmm I:wave: Always store after last use Then when race day comes around I discharge and charge

I'm not sure if I stated that corectly... It should be charge, and recharge while in use. then discharge to 3.3 volts per cell when not in use.

I was led to believe that you DO NOT want to store a battery discharged to 6.0 for 2S or 3.0 for 1S. 50 % was all I remember hearing for storage purposes. When I finish the main, battery gets put in the sack til next race day and then just re-peaked. Have fun tonight Al!!! :thumbsup:

I was led to believe that you DO NOT want to store a battery discharged to 6.0 for 2S or 3.0 for 1S. 50 % was all I remember hearing for storage purposes. When I finish the main, battery gets put in the sack til next race day and then just re-peaked. Have fun tonight Al!!! :thumbsup:
ditto:wave:

I was led to believe that you DO NOT want to store a battery discharged to 6.0 for 2S or 3.0 for 1S. 50 % was all I remember hearing for storage purposes. When I finish the main, battery gets put in the sack til next race day and then just re-peaked. Have fun tonight Al!!! :thumbsup:
This is another case of people focusing on old info.

The instructions that come with current SMC packs say that 50% is fine for storage, but if you are a racer that wants maximum runtime form you packs, store them at 3.3V and check them every so often.

This is another case of people focusing on old info.

The instructions that come with current SMC packs say that 50% is fine for storage, but if you are a racer that wants maximum runtime form you packs, store them at 3.3V and check them every so often.

Didn't know that! Been a while since I bought a new pack! :cool:

Just a few thoughts for you guys,

I have been using lipo batteries of all sizes and milliamps in rc helicopters for the past two years. Here is what those manufacturers say about handling and care for best performance and life out of the battery

1. Charge at 1C, some newer batteries are going to 2C but is it really going to save that much in charging time?
2. Let battery get to room temp before using
3. There is no need for discharging a lipo battery other than using it in the heli/car
4. Do not use anymore than 80% of a battery meaning when you charge the battery after using it, lets say it is a 5000mAh, you should not be putting any more than 4000mAh back in to.
5. When not using a lipo for an extended period of time, you should charge the battery 50% and then when you are getting ready to use it, top it off.

Like I said, these are the general rules that us heli guys use and it makes a big difference on performance and life of the battery. Hope I was able to help some :)