For those who are running the LIPO/B.L. motors that are concerned about teching for 'overcharging' , one of our racers had a brilliant idea.

Using a battery bar cut in 1/2 and soldering it to the wire inbetween the 4mm battery plug and wire leaves a tab you can easily probe with a volt meter w/o having to remove the body on most oval pan cars.

http://www.southwesttour.com/images/lipotabs.jpg

This would make tech very easy and painless...

Great idea ! I was thinking about something like that.

that's a short just waiting to happen guys

that's a short just waiting to happen guys

Well.. there is that :-(

I agree with the short thing, it scares me, something could get stuck in there, like someone else's car. LOL

that's a short just waiting to happen guys

I agree all it takes is one wrench to fall in the wrong place and poof.

I had thought the same thing...but it's really no different than having your tabs exposed on your NiMh pack is it? How many times have you shorted those?

(Myself...several times..but never when the battery was IN THE CAR)

Why couldn't you just attach a wire with a deans female connector on it (or something like that). You could stick the volt meter probe's in the connector, but it would still be protected from shorting out. Just an idea.

jdub

one of the things I thought about doing was to solder a wire w/ 2mm female bannana ends in shrink wrap and put them where they won't get caught up on anything..and a DVM probe would be perfect size....but if you are not careful..someone SLY will stick a resistor inline - andmake the reading read LOW.

People wouldn't cheat would they....:rolleyes:

I dont really know much about the Lipo stuff, but it was an idea I guess.

Won't work with my lipo try..
Joe-Are you guy's really checking voltage and what would SWT consider max tolerence?
Hopefully see you guy's soon for some velo this year.

Kevin,

I'm going to check some at Random, we've also got a inductance meter coming to check motors.

Our voltage will be 8.40 volts with a .05 +/- reading with OUR meter. So it can tip upto 8.45 volts prior to being set on the track with "OUR" meter.

Who will be checked? How often? TBD...by the way guys run, and what I see.

Personally, I don't feel it's going to be a issue...but there are a few racers who are themselves unsure...so hopefully this will help ease their minds.

Joe- find a small rubber cap to go over the ends- takes care of it. Or, take some thing like Plasti-Dip (for tool handles) or liquid electrical tape and cover them- but leave a small area exposed to be able to put a probe on. Should solve the shorting issue.

Good idea, though...

The difference between your 4 cell pack and the lipo pack with battery bars is about 2 inches. so your going from a little over 1 inch apart to about 3 1/2 inches apart. I dunno about you but thats a lot further for something have to hit to short your batteries. Also NIMH just spark a bunch and are a lot less dangerous if they blow up then lipo cells. I dont see why it would be a big deal to ask every racer to use the bana plugs that come with a lipo pack, and ask them to come to the tech station with there battery unplugged. Its not hard to lift the side of the body and place the banana plugs in the battery.

RyanJacks...

You've never seen a VELO car... abut 2/3rds of them are sealed up tight like a tank.

I don't think it's going to be an issue really - just looking at things to make things even easier.

as far as shorting of NiMh vs LIPOs...

The NiMh's don't have a plastic case...and I've seen packs get rubbed through in shrink & short against the carbon fiber chassis...you know we strap those things as tight as possible to a piece of conductive material with very little protection..(I've always been suprised we don't have more shorting issues.)

We have been teching for inductance and battery voltage in our 17.5 lipo class for 2 weeks now. Lipo's have tested from 8.33 to 8.55. Inductance on the 17.5 bl motors has been from 62 to 68 on the meter.

Hey Joe, I had an idea ever since you posted these pics on the SWT site. What about using a BEC connector? Just soldier the wires in w/ the 4mm plug and run the wires together. It can sit next to the on/off switch. You plug in and there you go! It can be kept fairly neat and be out of the way. Just a thought....:confused:

Ballistic Bill, I noticed that your data had packs that SWtour would DQ, I.E. 8.55, have you done any looking into how the packs above 8.45 where charged, what model of charger? what charge rate etc>??

We have been teching for inductance and battery voltage in our 17.5 lipo class for 2 weeks now. Lipo's have tested from 8.33 to 8.55. Inductance on the 17.5 bl motors has been from 62 to 68 on the meter.


8.55 is kind of high?

what kind of charger?
what kind of lipo?
what kind of volt meter?

I can answer for Ballisticbill on the voltage. If the SW tour is DQ'ing for batteries over 8.4 then they should not. Lipo's vary in peak voltage (just as sub c's) some no matter what brand of lipo or charger. That is why at our track (Speed Zone) we have give a high end of 8.6v because it is nothing uncommon to see that. Of the three batteries in our personal cars they vary from 8.45 to 8.55 at peak. Tracks have to give some tolerances to be fair but Im right there with them on the "overcharge" situation. We had it going on a couple of weeks ago. Driver was seen doing it, admitted doing it, said it should be legal and his race buddy screamed cheater at him all day, then when we took a good run from him he tried to deny it.

I think for this sport to get back on track we as track owners need to step up and throw cheaters out. It may sting a little at first but in the long run it will stop the "gray area" crap that some call it. IT IS BLACK OR WHITE.....ETHICAL OR UNETHICAL. We may have to throw one or two out but it is keeps 6 others from quitting because they dont like the "gray" area stuff then there is an upside.

I have been told by customers that they will not attend tracks allowing the "overcharge". So what does that track gain......it doesnt.....it loses

Rob @ Windtunnel

I set the SWT "max" voltage at the ROAR voltage I believe...actually, I think mine was just a tick higher.


Here is an excerpt from the ROAR ruling on Lipo Charging, and we put a very small variance in this to allow for less accurate DVM readings...(NOTE: We are NOT using ROAR's rules, but I am trying to keep some things very close - We DO use one battery exclusively ORION 3200)

http://www.southwesttour.com/images/roar_lipo_rules.jpg

Roar's was 8.44 max. (thanx swtour)

again what charger and what battery?

I sure would hate to be the poor guy with 8.3 volts racing the guy with 8.6 and not have a legal way to get them that high just cause the higher voltage person is using a less than great battery and or charger.

Rob,

What batteries are you running and what chargers?

Of the three batteries in our personal cars they vary from 8.45 to 8.55 at peak.

and for those that snug up their ESC right behind the battery.. that aint gonna work.

Chargers we have everything here for testing. CE, FMA, orion, Imax, Checkpoint, you name it.

Batteries we have Windtunnel, orion, track power and one other off brand.

If roar is setting 8.44 for peak voltage there are a lot of batteries that will have to be discharged before a race or will be illegal. It is nothing uncommon to see 8.5 sitting idle on any brand. I had one go goofy on me a while back and was higher than that but after a couple of balance cycles it was just fine

Where I have seen voltage increase it appears at this time is if a pack is not balanced very often. I rarely balance mine that I race but in bench testing this is what I have seen. But think about it. We are talking very small numbers such as .05 to .2. That is a very small margin to work with or have as a spread. If someone thinks every single lipo pack is going to peak at 8.44.....think again. They are man made and the goody inside lipo's can vary just like any other battery out there. Go buy a duracell or energizer. You can find variables in those as well.

The overcharging of lipos is very very easy to tech for. We have other areas that are much more of a problem right now. I still believe in lipo racing very much. Just my opinion though

Some chargers are made with not so great components and the same goes for some batteries and this can affect the standing voltage and that is the reason I asked the question.

i heard that the lipo charge in the MRC will bump it up to 8.5 or higher, hence why Orion doesnt recommend the MRC lipo chargers..... :| just what i heard.

i heard that the lipo charge in the MRC will bump it up to 8.5 or higher, hence why Orion doesnt recommend the MRC lipo chargers..... :| just what i heard.


Not the only charger that does that!

Who carries "lipo sacks" required in ROARS rule 8.3.2.7.3 this is listed under disqualification.

SWT,

At this time, I am on the campus of the University of Iowa and I am only going from memory.

I am aware of the voltage limit that ROAR set. The first week I also set the limit at 8.45 until I saw the spread. The second week of teching I was coming up with similiar numbers. Remember that my objective was to stop the intentional overcharging of Lipo's to what I suspected was over 9.0 volts. The 8.55 readings came from several different brand batteries and from different chargers just like Rob said. This Sunday, I am going to keep a written record of the brand of battery and the charger being used. The 8.33, I know, came from two gold hard case batteries but did not get the brand but Rob may know what it was.

I will tell you one thing tho. It takes a lot of time to have to do this teching of lipo's and BL motors. It is unfortunate but it has to be done. And remember. Our teching is for voltage and inductance. How do we check speed controls is the next thing?

I'll try and have more info next week on what we see Sunday.

Bill Murdock

The low voltage lipos we saw were Trak Power in the gold case. Now this does not mean anything other than those two were out of the same pits. We saw others that were on the high side. :confused: from other pits

Like mentioned above by myself and Bill.......there are other areas that need to be watched:(. Battery voltage is easy to tech.

Rob

98Ron

Tower is one of the places you can get LIPO SACKS - But I'd guess since ROAR has made them mandatory w/ the use of LIPOs, soon you'll be able to get them at ALL your favorite RC Stores...

LIPO SACK (http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXSEA5&P=ML)

http://www2.gpmd.com/image/w/wwlp1000.jpg

I have been using an Army surplus ammo can, drilled a hole near the bottom just large enough for my charger leads to feed through. I wonder if that would be considered safe enough...?

I,d just like to say that even though theres ALOT of BS on the net about Lipo batteries currently, on how they can be Cheated/Overcharged/Burn your stuff up, I Absoulutely Will Put Up With Whatever It Takes To Run Them as far as Teching them goes.

Why you ask?

Its Febuary 16th 2008 and these are my Battery BILLS for THIS YEAR ( I race both Lipo and NIMH classes regularly )

Nimh: $240.00 plus shipping, I have 3 Good Race batteries ( hopefully they,ll last for a couple months if I pamper them and am LUCKY ) and one pile of charred remains currently in route to matcher.

LIPO: $00.00 , Bought one Orion 3200 Carbon last October for $79.95 I,ve ran the #$%@ out of it and possibly abused it somewhat.....Its still competitive with all the other batteries in our 21.5 Lipo class and the raceing is Fun/Fast/Competitive.....did I mention FUN!!!

P.S. To my knowledge neither of the two local tracks I race at have had a Lipo battery failure.

I can answer for Ballisticbill on the voltage. If the SW tour is DQ'ing for batteries over 8.4 then they should not. Lipo's vary in peak voltage (just as sub c's) some no matter what brand of lipo or charger. That is why at our track (Speed Zone) we have give a high end of 8.6v because it is nothing uncommon to see that. Of the three batteries in our personal cars they vary from 8.45 to 8.55 at peak. Tracks have to give some tolerances to be fair but Im right there with them on the "overcharge" situation. We had it going on a couple of weeks ago. Driver was seen doing it, admitted doing it, said it should be legal and his race buddy screamed cheater at him all day, then when we took a good run from him he tried to deny it.

I think for this sport to get back on track we as track owners need to step up and throw cheaters out. It may sting a little at first but in the long run it will stop the "gray area" crap that some call it. IT IS BLACK OR WHITE.....ETHICAL OR UNETHICAL. We may have to throw one or two out but it is keeps 6 others from quitting because they dont like the "gray" area stuff then there is an upside.

I have been told by customers that they will not attend tracks allowing the "overcharge". So what does that track gain......it doesnt.....it loses

Rob @ Windtunnel

OK -- help me out here.

I run the Orion 3200 pack (every one does at our track -- it is the only pack that is legal). I have a Checkpoint 1030 charger. I balance my pack ever couple of weeks -- only if the two cells get more than 0.1 v apart.

I have NEVER EVER seen my pack charge at over 8.401 V -- EVER. I've also checked another guys Orion 3200 in the pits that was charged on a CE GFX -- also peaked at 8.40 V.

So how the H - E - double-hockey-sticks can you get 8.55 V ???!!??

...you should have heard all the "Man - I can't believe how EASY this Lipo deal is..." all day today at the VELODROME race...

A couple guys ran multiple classes - and ran lipo in both classes.

No Soldering Iron - Hardly any equipment on the table - they felt LOST because it was SO easy on them...

Our weight rules are 38 oz. A few of the battery sponsored guys were allowed 2 options to run w/ the LIPO guys.

Option 1) They get to run the same motor (17.5) but run it on 6 cell - but they are penalized by the weight of a 6 cell NIHM running against a 3200 LIPO.

Option 2) They get to run a 10.5 w/ 4 cell Nimh - they still get a weight penalty cause the 4 cell is heavier - but they also get a little hotter motor.

They tried both - but the 4 cell proved to be the more competitive choice...and was as it was last season - almost dead even between 17.5/LIPO and the 10.5/4 cell. (The 6 cell just couldn't quite hang...)