LiPo packs and overall weight .....

[RogerM]

A post on the MK GP thread about weights got me thinking about this so I thought I'd start this poll to see what the world at large thought .......



So what do you think about forcing LiPo runners to add at least the amount of weight that would be required to make the combined weight of the Lipo pack and it's ballast say the same as a pack of 3700s????
(purely from the point that would be the minimum cell likely to be powering a quick brushless equuiped car)

Based on that post Cosie tells me his S2 with LiPo in weighs in at 1525g (still loads above the BRCA minimum 2wd weight so no probs there) and I stated that my RB5 with 4500s in will be nearer 1700g .......

Now to save the brain cells (I know some are running low on those as S.A.D. takes it's toll) that is 11.5% extra my poor motor has to accelerate out of each and every high grip / low speed corner and punch across the jumps too.
Now I could make that up by driving 11.6% better (but I'm not going to count on that too much!!!).

So here's the point (finally you all cry) .......

If Cosie's Lipo pack weighs in at 150g less than a pack of 3700s and my 4500s tipped the scales at 25g (guessed difference) over the 3700s BUT the rules stated that he had to make up the difference in ballast on / under the LiPo pack IN ADDITION to any weight on there for handling reasons it would level the playing field again .....

That would leave me with some choices to close the gap, dremel, run 3700s, buy loads of light weight bits-and-bobs, go and have a cup of tea and not worry about it!

Does that make sense (as far as the question is concerend)??????

I know there would still be those that say what about the 0.4V nominal voltage increase etc. but lets be honest ..... for anything much quicker than a spec the extra voltage isn't going to matter a jot. In fact most modern NiMh cells run about 1.23v anyway so that's 7.4V!!!

[Alfonzo]

What is it about 'the whole Lipo thing' you don't like?

[burgie]

as long as the "lipo"car is the minimum weight, there is no problem.

Use Lipo's or use Ni-Mih, the choice is yours - if you don't want to, don't try to suggest others should compensate for your whims. The Lipo bashing is growing a tad tiresome now.

[Smartalec]

Originally Posted by burgie

as long as the "lipo"car is the minimum weight, there is no problem.

Use Lipo's or use Ni-Mih, the choice is yours - if you don't want to, don't try to suggest others should compensate for your whims. The Lipo bashing is growing a tad tiresome now.

Well said...... new technology is good for everyone I think. I remember people knocking 2.4ghz and then the same with brushless.

[Gnarly Old Dog]

I'm with Alex - so long as the car weighs at or above the BRCA minimum limits, then they comply to the prevailing regulations - be they either LiPo or NiMh powered.

There are (as I'm sure we'll all learn soon enough) plenty of situations where the known but comparatively heavy configuration of a NiMh car will be easier and more forgiving to drive than its LiPo counterparts.

Come the 1st national in 2009, if the conditions get slick or bumpy during the day, I'm sure there will be plenty of newly LiPo converted runners who'll be busy adding weight to their cars just to get the handling balance back to something more normal that they're more used to - and lets not forget that 8mins of practice isn't a great deal of track time to start trying to learn how a new car or weight distribution really works.

Besides, I've got no idea where I can put 170g's worth of ballast in my 4WD

[RogerM]

Originally Posted by burgie

The Lipo bashing is growing a tad tiresome now.

I'm not LiPo bashing not at all, just throwing an idea out there that's all!!!

In gerneral response ......

The power delivery thing first .... I want less not more ..... that's what I meant, personal choice though.


The weight issue is really aimed at those that are on tight budgets and planned on reusing there 08 cells in 09. A new charger and a pack or 2 of LiPos might be more than the budget can stretch to!
If they feel that they are at a big disadvantage before they even start they may not go to the race meetings in the first palce. The last thing we can afford to do as a sport is turn people off. Afterall the entry fee of these people is at least as important to the club holding the meeting as that of a world champ ... in fact these are the sort of people who probably race at that club every week and thus might be considered more imprtant than a roaming superstar!!

BigRed ...... garlic bread might be a meal feature but the future ... I think not



(I know Super_Dan will be along in a while ..... did I mention starting a debate??? lol)

[bigred5765]

everyone will have to run to minimum weight at nationals any way, so wont make any difference, lipos are ace, and like garlic bread they are the feature,i think a more sensible poll or question would have been why wouldn't you run lipos,and the way they deliver power is miles better than nimh,we were running 6.5 last week were before lipo it was almost always a 5.5,less heat less stress less wear,

[Smartalec]

Originally Posted by bigred5765

everyone will have to run to minimum weight at nationals any way, so wont make any difference, lipos are ace, and like garlic bread they are the feature,i think a more sensible poll or question would have been why wouldn't you run lipos,and the way they deliver power is miles better than nimh,we were running 6.5 last week were before lipo it was almost always a 5.5,less heat less stress less wear,

.... garlic bread is the FEATURE

[RogerM]

Originally Posted by Alfonzo

What is it about 'the whole Lipo thing' you don't like?

Valid question .....

I personally don't like the way they deliver their power, but that's my own opinion based on what I like. I plan on staying with NiMh for 09.

The main issue for me is the one this poll is based on .... how to level the mass based issues between NiMh and LiPo racers. More mass is bad in both the breaking and acceleration zones ... the two places where most time can be found on track!!!

The other thing that worries me a little is the abusive charging / handling issues. Somebody will do something stupid with LiPo and set the damn thing on fire, worse case taking a sports hall with it on a club night. I know that the serverity is no greater than a NiMh blowing up (some would say more confined so maybe even a little better) however little Jonny is unlikely to have IB4200s or any of the other suspect cells and also unlikely to be trying to charge them at 1,000,000 amps. What I am trying to say is those that are at the most risk from blowing up a NiMh are unlikely to actually achieve it.

That said, if all the shops are responsible and explain why it is a good idea to always charge in a quality sack, not abuse the cells and only provide quality equipment then I can not honestly see a problem with LiPo safety.
The problem will come when they filter down to the mail order catalogues, Argos etc. or even those local model shops often staffed by people who can barely grunt their name let alone provide good quality advice to a noob.
It's not the experienced racers and quality race shops that worry me with LiPo, it's little Jonny who shops at "Neandertal Models"!!!!

[frogger]

I'm with you Roger, lipo's are voodoo magic and should be banned completely, just like fireworks and pixies. They contain non earth-like materials that are way too complex for humans to understand and besides they are the wrong shape, I mean what's up with these square edged flat batteries? They just look weird. And a linear power curve!? That's simply ridiculous.

Couple that with the absolute stupidity of staying cool while charging, it just doesn't compute. There are so many issues to consider, weird power delivery, reduced weight, being able to charge them and re-use them many times in a day and all that. It will change this sport forever and things will get totally out of control freaky. What's next? Batteries that don't need charging in cars that don't break? What will we do in between races? Will we actually have to talk to the people next to us and be all friendly like



lipo's rule dude, get with the program.

[RogerM]

Originally Posted by frogger

Batteries that don't need charging in cars that don't break? What will we do in between races? Will we actually have to talk to the people next to us and be all friendly like



lipo's rule dude, get with the program.

If BigRed is right and garlic bread becomes the norm do you really want close contact with your fellow racers?????


Why did I know people would see this as LiPo bashing ..... go back to my original post and find the bit where I say LiPos themselves are a bad thing ..... it's not there.

I have nothing against people running Lipo .. nothing at all.


Discussion is a good thing people ........

[Belsten]

cheesy garlic bread for sure

I dont necessarily agree with the budget side of things. You can buy a trackpower saddle pack I believe for £45 new and you could run all day on the 1 pack. You would struggle to buy 2 budget packs of nimhs for that, especially assembled with bars connectors etc

[Smartalec]

Personally, I think lipo's are BETTER for us normal folk and level the playing field. I don't mind being beaten by anyone who drives better than me (and that's a lot of people), what I do hate is being beaten by people with access to superior equipment. Anyone who races, and that includes Friday night drivers on a budget or superstars, knows that you have to buy batteries/motors etc. With lipo's you can get away with a couple easy and the price tag is no worse than a decent pack of NIMH. Coupled with that to keep the NIMH from going off you have to have a superduper equalizer/cell nurser and never ever breathe on the things. ........ Put the biggest capacity lipo you can in your car and you'll never get anywhere near to dumping so the lipo will stay in top condition. Get rid of all the expensive charging/discharging/looking after stuff and spend the money on a couple of packs of lipo's ......... as Lion-O said (almost), it's the future

[Smartalec]

I'd say that if you choose to run NIMH in your car and I choose to run lipo in mine, as long as mine is still above the weight limit then that's fine. I honestly can't see why anyone would want to run NIMH when the chances are the availability of good quality packs will be in short supply as they have been for a while and also the lifespan of the packs is terrible. Almost everyone I know has had problems with cells going down in packs over this last season and the problem will only get worse as more and more cell distributors go over to lipo....... of course, this is just my opinion

[Belsten]

To be honest I would say that this would be extremely hard to police and would not be viable. Different cells from different manufacturers weigh different amounts. You could be faced with the prospect of setting the weight limit using GP 3700's but what if someone were to run Intellect 3700's ?Scrutineers would also be faced with the prospect of asking every racer/mechanic to remove their cells from their car to weigh them along with weighing the car & cells. It can get frantic during scrutineering as is

I fully understand your point though

[James]

My personal experience:

My trakpower packs weigh roughly 4 sub c's so when i first ran my X6i put two infront of the lipo to simulate 6 x sub c's - the car wasn't that great, but was superb with the LIPO alone..I run no ballast. There are few folks that disagree but my last result at worksop showed that it suits me personaly..

I have a lipo cat and a nimh one, they both feel pretty similar. The LIPO perhaps feels better indoors as its a bit more snappy, all i've done to it is add 15g on the rhs to even up weight distribution L to R..

I'm not really worried that i'll have to bring the cars up to weight for Nats, i can just play about to find where it goes best.

[Chris Doughty]

Originally Posted by RogerM

A post on the MK GP thread about weights got me thinking about this so I thought I'd start this poll to see what the world at large thought .......



So what do you think about forcing LiPo runners to add at least the amount of weight that would be required to make the combined weight of the Lipo pack and it's ballast say the same as a pack of 3700s????
(purely from the point that would be the minimum cell likely to be powering a quick brushless equuiped car)

Based on that post Cosie tells me his S2 with LiPo in weighs in at 1525g (still loads above the BRCA minimum 2wd weight so no probs there) and I stated that my RB5 with 4500s in will be nearer 1700g .......

Now to save the brain cells (I know some are running low on those as S.A.D. takes it's toll) that is 11.5% extra my poor motor has to accelerate out of each and every high grip / low speed corner and punch across the jumps too.
Now I could make that up by driving 11.6% better (but I'm not going to count on that too much!!!).

So here's the point (finally you all cry) .......

If Cosie's Lipo pack weighs in at 150g less than a pack of 3700s and my 4500s tipped the scales at 25g (guessed difference) over the 3700s BUT the rules stated that he had to make up the difference in ballast on / under the LiPo pack IN ADDITION to any weight on there for handling reasons it would level the playing field again .....

That would leave me with some choices to close the gap, dremel, run 3700s, buy loads of light weight bits-and-bobs, go and have a cup of tea and not worry about it!

Does that make sense (as far as the question is concerend)??????

I know there would still be those that say what about the 0.4V nominal voltage increase etc. but lets be honest ..... for anything much quicker than a spec the extra voltage isn't going to matter a jot. In fact most modern NiMh cells run about 1.23v anyway so that's 7.4V!!!

If you are that worried about getting yourself a super-light car run 5 cells and a 4.5 motor.

maybe you are forgetting that this is off-road and that sometimes a bit of weight in the car is a good thing, calms the car down, slows down its reactions and helps you get an error free run

[Alfonzo]

I almost don't dare post this as it all gets sooo tedious, but here goes anyway..

Regarding safety - I personally saw some NiMh explode. Twas very very nasty indeed.

Prediction: NiMh won't even be an option in 12 months time.