Lead Weight For Lipo

[Cockerill]

Originally Posted by SlowOne

The Worldwide point is a good one, and we need to ensure that the weight limit proposal is put to EFRA next week for inclusion in this year's AGM. What's the new weight limit we need?

Why do we need to change the weight limit? We could keep the one we have as it has been fine for the last 10+(?) years and we've had plenty of changes in equipment and materials (Nicad-NiMH, Brushed-Brushless, 40MHz-2.4GHz, Plastic-Carbon Fibre).

Originally Posted by SlowOne

The funniest bit is that you're all chasing obsolete technology. The future is not in LiPo it is in the LiFePo4 cells currently sold by A123. Costs less, charges faster, lasts longer, much safer, much more robust, and provides a voltage that every electric class can use.

If A123 is the cell we should all be using, why aren't we? It's alright saying it's the future, but in a couple of years there will probably be a 'new' technology that we should wait for, but wait that will be superseded again so we should why for the 'newer' one, and hence we will always be on NiMH cells.

Lipo was the 'new' technology a couple of years ago for cars, it's now in mainstream-ish use and has got to a stage where it is safe (hard case) and the right size to drop in to 99% of cars.

At the minute Lipo is (over NiMH) everything you mention A123 is, so why not use that whilst we can, it's got to be better than NiMH. Then when A123 become an option for cars and people are using it we can look at changing the rules for that.

Or maybe we should wait for hydrogen power to come to our cars, as that is clearly the future.

[SHY]

Spot on Cockerill!

BetaMax, 2000, MiniDisc etc. were surely great products... better than what became de facto... but you gotta adopt what's here NOW... There will always be progress!

[Northy]

I did a little reading on the A123 cells, they are spec'ed differently in terms of voltage, they are the charging voltage, so may actually be the correct voltages (within reason) for our use.

HOWEVER, currently they are MASSIVE! They would not easily fit in any of our cars.

G

[stefke]

Originally Posted by Northy

I did a little reading on the A123 cells, they are spec'ed differently in terms of voltage, they are the charging voltage, so may actually be the correct voltages (within reason) for our use.

HOWEVER, currently they are MASSIVE! They would not easily fit in any of our cars.

G

They fit a saddle pack car just fine in a 2x2 configuration.

[Lee]

Originally Posted by SHY

Spot on Cockerill!

Tut Tut Tut I think you will find its Multiple European A finalist Tom Cockerill

G,

I have a source who says that these a123 cells are getting smaller, much smaller

[Northy]

Originally Posted by Lee

Tut Tut Tut I think you will find its Multiple European A finalist Tom Cockerill

G,

I have a source who says that these a123 cells are getting smaller, much smaller

Speak to me!

[BRS]

I dont do electric racing but had a right laugh reading this thread.

Good stuff... how many of you would let your girlfriend read this stuff if you have one?

[Lee]

Yeah your girlfriend must be well impressed when you show her your new piston liner.

Feel that compression baby oooohhh

[BRS]

Pot.... & Kettle eh hahaha thats a good point they're not to interested in seeing how you made a special thingymebob for the "toy car" are they

[MK999]

Originally Posted by OldTimer

Trakpower 3200 lipo stick or saddle £45, trakpower charger £38 total = £83

3 packs of Orion SHO 4200 @ £57 (maybe £60 with bat bars etc) = £171.00 (£180)

There is a good chance that you will replace cells over the winter for the new season, unless you are using some GP3700, so you can see how it reduces your costs

GP3700's would be me yes I know that li-po to buy as a set up is cheaper, but disadvantaging those that still run ni-mh by changing the weight limits is not the way forward, I would think most people if they knew that li-po was being brought in slowly would definitely change come the time for new batteries, I know that I will be looking at it very closely when the time comes to buy new batteries.

Maybe I'm in a very unique situation with batteries that would last long enough for it to work out cheaper in that short run, but a changing weight limit would almost definitely be an extra cost in terms of having to buy li-po's instead of running my current ni-mh's, as soon as most of the people racing are using li-po's tho, definitely all for it

[OldTimer]

I cannot see any need to change weight limits you can get a ni-mh powered car close to the minimum limit if you really want to.

[MK999]

Well that was what my comment on it increasing costs (in the short term at least) was related to, the introduction of li-po is the obvious way forward for the sport

[SlowOne]

Originally Posted by mark christopher

which would make it dearer...................... defo need another charger, diff mores to cope with lower voltages ie 4.5 3.5

ROFLMAO - this is exactly the argument I put when you were banging the LiPo drum a couple of year's back. Now the tables have turned, eh??!!!

2 cells will make 12th and Oval, and will equal 5-cell touring. Make the Spec motor a 9.5 and it works there, and make the motor used in Off-Road a 4.5 or 3.5 and it works there.

The problem with LiPo is that at 7.4v it is burning motors out in TC Spec (ask anyone who tries to be competitive) and at 3.7v it doesn't suit anyone else. LiPo are volatile, can't be charged in 15 mins (and you were the one wanting convenience and lower numbers of batteries to carry around) doesn't deliver the amps unless you have more capacity than you need, and requires an investment in new springs, oils, suspension settings and tyres to use the lower weight limit.

Let me see now, I could invest in all that, and probably a new car, or I could buy one pack and a charger for under 100 notes and drive all day - it's a toughie!!

Sorry Mark, but you are now the person who does not want to move with the times - never thought I'd say that!! The future is LiFePo4!!

[Cockerill]

Originally Posted by SlowOne

requires an investment in new springs, oils, suspension settings and tyres to use the lower weight limit.

What lower weight limit? I thought we had discussed this and 99% of people decided it was better to keep the current limit

What I am saying is yes LiFePo4 MIGHT be the future but it isn't at the minute. Right now Lipo is the future as it has been proven to work in RC Cars.

Just like brushless was the future (and used) for at least 1 season before it came legal.

There is no point missing Lipo out as that means another 2/3 seasons of NiMh with at least 3/4 packs a season, when you can run on 1 Lipo pack, per car, a meeting (I've done it, and I didn't need any new springs/oils/tires).

Once A123 cells have had some in use in cars and have been proven to work, that's when we start looking at having them as legal cells, until then, I'm afraid Lipo is the future.

PS. oOple is a majority off-road place, not many care about touring cars!
PPS. SlowOne, Are you American?

[mark christopher]

Originally Posted by mark christopher

which would make it dearer...................... defo need another charger, diff motors to cope with lower voltages ie 4.5 3.5

Originally Posted by SlowOne

ROFLMAO - this is exactly the argument I put when you were banging the LiPo drum a couple of year's back. Now the tables have turned, eh??!!!

2 cells will make 12th and Oval, and will equal 5-cell touring. Make the Spec motor a 9.5 and it works there, and make the motor used in Off-Road a 4.5 or 3.5 and it works there.

The problem with LiPo is that at 7.4v it is burning motors out in TC Spec (ask anyone who tries to be competitive) and at 3.7v it doesn't suit anyone else. LiPo are volatile, can't be charged in 15 mins (and you were the one wanting convenience and lower numbers of batteries to carry around) doesn't deliver the amps unless you have more capacity than you need, and requires an investment in new springs, oils, suspension settings and tyres to use the lower weight limit.

Let me see now, I could invest in all that, and probably a new car, or I could buy one pack and a charger for under 100 notes and drive all day - it's a toughie!!

Sorry Mark, but you are now the person who does not want to move with the times - never thought I'd say that!! The future is LiFePo4!!

go on then, if you used that argument................... explain!

do at least 50% of chargers cater for lipo?, now how many cater for a123 cells?

lipo is .2 volts higher than nimh, no motor changes needed, explain how your saying its cheaper yet you say you need to buy lower winds? your also increasing voltage on at least 3 of your mentioned classes and reducing it in off road

i dont see anyone blowing motors, unless there over gearing which will happen no matter what power source.


no go show me where im not moving with the times, lipo is here NOW, its stable and we can go there next year, as packs fit cars NOW.

if in another year the A123 are proven to work and can fit in cars/classes then yes ill use em, but i live for now, and what we have is lipo,

have you actually used the A123 cells?

[mark christopher]

tom no he is not from the usa, from the uk

[Stu]

Originally Posted by Lee

Yeah your girlfriend must be well impressed when you show her your new piston liner.

Lee - don't diss people from Burnley, they are special.

[mark christopher]

Originally Posted by Stu

Lee - don't diss people from Burnley, they are special.

yup they even have thier own "special" hospitals

[SlowOne]

Originally Posted by mark christopher

go on then, if you used that argument................... explain!

do at least 50% of chargers cater for lipo?, now how many cater for a123 cells?

lipo is .2 volts higher than nimh, no motor changes needed, explain how your saying its cheaper yet you say you need to buy lower winds? your also increasing voltage on at least 3 of your mentioned classes and reducing it in off road

i dont see anyone blowing motors, unless there over gearing which will happen no matter what power source.


no go show me where im not moving with the times, lipo is here NOW, its stable and we can go there next year, as packs fit cars NOW.

if in another year the A123 are proven to work and can fit in cars/classes then yes ill use em, but i live for now, and what we have is lipo,

have you actually used the A123 cells?

Mark, you really do make me laugh!! These are all the things I said to you when you were saying we had to go LiPo because it is the future. I'll have one last try...

12th can use 6.6v and go to lower-wind motors. TC can use 6.6v for both Mod (much as it is) and Stock - just change to 9.5 motors. Off-Road can use 6.6v by upping their motors to 4.5 or 3.5. It's a universal voltage for all, it doesn't need any receiver packs and it can be run in any class now except 12th - the voltage is a maximum, not a minimum!

The problem with motors burning out in TC is a voltage problem, and now the motors are stronger people are losing speedos (the next weakest link in the power system) except where the voltage is lower. TC Mod and 12th have no problems, nor does anyone using 5 cells or less. 6.6v makes the power system more durable than 7.4v without any loss of speed.

When LiPo first came out they didn't fit the cars - some don't now.

When LiPo came out, NiMh was there then.

It doesn't come without any changes, and neither did LiPo. It's the future because it is not volatile and doesn't need an extra case to put it in. It can be charged in 15 mins so you only need one pack. It can discharge at higher rates than LiPo or NiMh. And yes, you have to buy a new charger, but at £40 that's hardly a problem.

I have no idea what A123 will do with pack sizes, and no I haven't used one. But, when they do come out with a stick pack for my buggy, I will buy one and I will use it. It is the fastest growing technology for batteries, and it is being used in power tools now. It is being tested by lots of computer companies, and it is the future replacement for NiMh in hybrid and electric cars.

Everything that is powered by batteries is looking at this technology as its future - why not RC? Argue away my friend, but this is the future. I won't be going down that track, but there will be plenty who will. this is simply a better battery technology than anything we have, so if it happens this year, or the next five years, I don't mind - but it will happen.

I'm sure you'll come back on this, but I'll not hog a thread on our little discussion. I'm happy to wait, and to support new technology - are you just stuck in a LiPo rut?? !!

[Richard Lowe]

Originally Posted by SlowOne

The problem with motors burning out in TC is a voltage problem ... 6.6v makes the power system more durable than 7.4v without any loss of speed.

Not true, to produce the same amount of power with a lower voltage higher currents are needed, which produce more heat. How else could you pull hundreds of watts from a wall socket without the thinner wire melting? Yet we need 12 guage in out little cars...

Batteries can only give so much current out, dictated mostly by their internal resistence. Moving between a 5 cell and 6 cell pack you will still have the same current limit, but higher voltage on the 6 cell pack so higher overall power output.
If you limited the current of the 6 cell pack to provide the same overall power (V=IR remember ) and kept the cars weight the same the 6 cell car would run cooler.