2008 Off road, Lipo

[mole2k]

Its not just time at the meeting, its time beforehand too. When racing weekly meetings and trying to charge batterys during the day.

[Spencer Mulcahy]

I dont think I will be going Lipo as I dont think it is needed in cars helicopters or planes maybe. As for being stuck in the 80s that is defo me as I have decided to ditch brushless and go back to brushed. Brushless to powerfull for me and my driving has gone backward.

[Richard Lowe]

I see no reason not to move to Lipo's once they are 100% idiot-proof, I'm looking forward to using them purely because of the lighter weight. Quicker acceleration/direction change, less wear on things; including tires, whats not to like? They will make the cars handle differently but thats nothing a change in setup won't fix, less pack and softer springs would be all thats needed. Adding weight to a car to make it handle properly is wrong if you ask me, if you're at the weight limit and you are having to add weight to the car either your setup or the cars design isn't right.

The extra voltage is a bit of a problem and would mean it wouldn't really be fair to run Lipo's and NIMH's togeather. Though there's nothing stopping us making the cars a bit of a handful to drive with NIMH's and brushless currently, especially in 2wd.

[MarkWesterfield]

One battery making an r/c car faster over another battery isn't really an issue. Nimh have this problem now, IB4200's are faster than the old gp3300, and everybody has IB4200's in their pits, so nothing will change with the 7.4 lipo batteries. The fast drivers will still be fast, the slow drivers will still be slow. One big problem I see is that its very easy to permenantly damage a more expensive lipo pack by running it under 3 volts per cell. Lipo cutoff speed controls are not enough of a standard yet.

I think keeping the minimum weight the same, and setting a future date far enough ahead for lipo legalization so everybody has plenty of opportunity to learn, buy, and adapt to lipo is the way to go. Say if the date was July 1st, 2008 for 7.4 volt 6000mah capacity lipo to be legal, I think the switch would go over smooth. Thats a year to buy a charger, batteries, and lipo freindly speedo's. I think a timeframe to a standard is what is needed.

[MarkWesterfield]

Richard,

Softer springs and less pack will not fix the amount of weight loss. The contact patch of the tire is smaller with less weight. You'll need softer compound tires and inserts to regain the traction as well, softer compound tires will wear faster (the car is still going the same speed), so you'll be right back in the same spot as far as tire wear.

[Richard Lowe]

Originally Posted by MarkWesterfield

Softer springs and less pack will not fix the amount of weight loss. The contact patch of the tire is smaller with less weight. You'll need softer compound tires and inserts to regain the traction as well,

Remember you have less weight to move around...

[MarkWesterfield]

but that weight is needed for the current tire designs to work correctly.

[Northy]

Originally Posted by MarkWesterfield

but that weight is needed for the current tire designs to work correctly.

Er.... certainly in the UK tyre design has not changed as cars have got heavier, and it would be the same for everyone anyway.

G

[mark christopher]

just to point out im answering questions not looking to arguee............chris/dcm!!

Originally Posted by PaulRotheram

i cant see where people are coming from with having more spare time by running lipos.. how long does it take to press the bloody start button with nimhs?

there is no discharging/equalizing/charge from flat, time is saved by finish your run, marshal (allow pack to cool) plug in charger and top up, so you can turn car round far quicker.
im lucky and have 4x lipo (which i loan 2 out for trial to anyone.) but in theory i could turn up with 4 packs and run a days racing without taking a charger and have the same performance, dont think i could with pre charged nimh charged the week before.

Originally Posted by mole2k

My local club runs 19t buggys indoors on polished wood, I would quite like to see Lipo purely from a maintenance factor. It would leave me free to do more work on the car or help some of the other members.

I do agree with Neil Oliver that I think the packs should come pre-assembled perhaps with just the option of a splitting a stick pack and have discharge protection circuitry built into the battery itself. You very well may argue that this is unessecary as some speedo's have it but the fact still remains a lot of speedo's do not have the lipo protection.

you can buy seperate voltage cut offs, novak, trakpower,jperkins and others all do em. when 6 volts is reached they cut the radio, i have used trakpowers and for a few seconds it stutters the motor then shuts the speedo down via the reciever link, they are relativly cheap, small and light

[mark christopher]

Originally Posted by Lee

Im no lipo fan either, i have run them in the TC a while ago and at the time they did give a slight performance increase, but this only helped to throw a wind quicker so therefore rendered them useless.

In off road we dont need more runtime, we dont need more "power" and frankly if i wasnt charging cells between runs i would have nothing to do once i go brushless.

howe about chatting with some mates?

[DCM]

Originally Posted by mark christopher

you can buy seperate voltage cut offs, novak, trakpower,jperkins and others all do em. when 6 volts is reached they cut the radio, i have used trakpowers and for a few seconds it stutters the motor then shuts the speedo down via the reciever link, they are relativly cheap, small and light

For me, that needs to be built into the pack not an add-on extra, as the low voltage can cause dire affects on the cell, so for a safety stand point, that needs to be fool proof, plus hard casing, then I think they would be viable as a cell, but until then, there is still a lot of reliance on peoples common sense.

[Cockerill]

To say that we won't have to equalise lipo's is just stupid. There are two cells in a pack and there are already equalisers on the market. Ensuring both cells are the same will be a performance advantage.

Originally Posted by MarkWesterfield

Richard,

Softer springs and less pack will not fix the amount of weight loss. The contact patch of the tire is smaller with less weight. You'll need softer compound tires and inserts to regain the traction as well, softer compound tires will wear faster (the car is still going the same speed), so you'll be right back in the same spot as far as tire wear.

I'm sorry, but if you are running the same tires surely you have the same contact patch, but less pressure. However, as there is less weight to move around you don't need as much pressure.

As batteries have got heavier I have not seen a harder compound released.

[PTRU]

FYI

At regional level you can amend the rules to suit under serton sections this being one if you take time to read the rules.

We allowed brushless to run 2 years before they became BRCA legal in our region so people could run with them if they turned up. I for 1 would not stop these battery's being used in the region as long as they do not give a health problem.

The reason for falling numbers at club level is many fold one being and the main one is there is not enough juniors U13/U16 coming into the sport this is the biggest fall in numbers, Dads have other things they wish to do with there time.

If you put a proposal into the BRCA it will be discussed at the AGM, you as a proposer will be able to put your piont of veiw across, how well you sell it is down to you. It will also be discussed at commite before hand.

I know this has been mention before but you will get a fare chance for your proposal.

If you do what most people do:- Nothing then carry on and moaning.

[mark christopher]

Originally Posted by Cockerill

To say that we won't have to equalise lipo's is just stupid. There are two cells in a pack and there are already equalisers on the market. Ensuring both cells are the same will be a performance advantage.

not so
trakpower have a pack thats done over 100 cycles in a car and its still no diferent,

however you do not have to equalize lipo prior to charging you balance lipo and it will become the norm as good lipo chargers have it built in and the add ons balance the pack but its done whilst charging so it does not alter the cool/charge time

[mark christopher]

Originally Posted by PTRU

FYI

At regional level you can amend the rules to suit under serton sections this being one if you take time to read the rules.

We allowed brushless to run 2 years before they became BRCA legal in our region so people could run with them if they turned up. I for 1 would not stop these battery's being used in the region as long as they do not give a health problem.

The reason for falling numbers at club level is many fold one being and the main one is there is not enough juniors U13/U16 coming into the sport this is the biggest fall in numbers, Dads have other things they wish to do with there time.

If you put a proposal into the BRCA it will be discussed at the AGM, you as a proposer will be able to put your piont of veiw across, how well you sell it is down to you. It will also be discussed at commite before hand.

I know this has been mention before but you will get a fare chance for your proposal.

If you do what most people do:- Nothing then carry on and moaning.

what region are you in?

[PTRU]

Chilton mid south

[mark christopher]

Originally Posted by DCM

For me, that needs to be built into the pack not an add-on extra, as the low voltage can cause dire affects on the cell, so for a safety stand point, that needs to be fool proof, plus hard casing, then I think they would be viable as a cell, but until then, there is still a lot of reliance on peoples common sense.

i agree with most of above but to me adding the cut off to the pack is not a forward move,
1/ it will increase the cost of each pack
2/ your forcing drivers who have a lipo speedo to buy an additional cut off
3/ to remove pack you now need to also remove the reciever wiring from the pack
4/ its easy ot check a lipo speedo or a voltage cut off is fitted.

5/ all systems can be by passed so your back to common sence.

i have purpesly run a trakpower pack till flat, on my own in an open empty space as i like to experience what i preach where possible, no explosion, no fire, the biggest problem is in fact shorting the cell, which is a hazard to any cell format.
we have to educate and trust racers to act sensibly, thay already have that trust.

[mark christopher]

Originally Posted by PTRU

Chilton mid south

typical, wrong end of country, dont get me wrong if it was aimed at me, im not moaning, im happy to use either cell format.

[DCM]

I think it was Neil who said it before, but you won't buy a consumer peice of equipment that was built that didn't protect you and itself from a harmful discharge.

If the system is built in, then it can be used on ANY esc without issue. If them someone is stupid enough to bypass it, then that is there problem, but for the rest of us, it is peace of mind. If you want them more widely used then they HAVE to be user friendly out of the box, not needing this and that to plug in to make them safe for use (and I mean protected from under voltage situations...)

If I was the BRCA, then that is what I would insist as a primary part of the construction rules of the cell. I mean, if we wanted them cheap, we could just keep with the foil gel sacks and a fancy sticker, but that would not puch the cells along the way of acceptance would it.

[Cockerill]

Balancing/Equalising are pretty much the same thing. Altho it may not take extra time it is still an extra piece of equipment to purchase or a feature to pay for, and you are trying to say that it will not be necessary. Whilst it may not, the likely hood is that if there is an advantage to be gained by doing it, racers will.

We don't necessarily need to equalise nimh's, but the majority do because there is an advantage to be had.