Disadvantages of LIPO ?
 

Hi, I was wondering what the disadvantages of running LIPO are (if any) with the exception of limited availability of saddle packs are ? Thanks

More care is needed with charging etc,
expense too

chassis set up will need to be considerably changed to get it to "feel"the same.then again some do add weight to counter the change.recently i have been considering going lipo myself but the cost can get quite high when you take the need for a new charger into hand,speedo aswell

Expensive:confused: how can you say that??? CORE do a 5000mAH for £69.99 which will do you all day. You would need 3 maybe 4 packs of normal cells at £40 plus to do a meeting. Hope this helps:D

Hi,

It is possible to purchase an external lipo cut off device that plugs in between the speedo and the reciever. Probably much cheaper than a new speedo.

Also because lipos can be used many times a day you may well get away with only purchasing 1 pack. The demon hardcase lipo (5000mah) at £50 deliverd is the cheapest option i have seen.

some current chargers also have lipo charging functionality, although a balancer may also be required for occasional use.

Cheers

there you go then,i've been proven wrong and it seems lipo is really becoming the only option in a couple of years i didn't know they could be recharged several times a day i knew of the high charge rates (20 c )but thanks wish the brca would alough them in mods

I would only regard this as a short term disadvantage, as you would only need to do it once. Even if going back to NIMH for BRCA meetings, once weighted up the chassis - you can take a note of what lead goes where and it'll be easy.

What ongoing & long term disadvantages are there? Is punch decreased? Do motors run hotter? Do they damage easy from hard landings? Is the life of them short?

Disadvantages:

Mostly not being "sanctioned" or whatever the word is for 10th off road Nationals and thus Regionals for 2008.

10th off road will need a rule change to use them for 2009, this will have to be proposed and accepted.


I think advice is charge at 5 Amps, not high rates.

is lipo legal at club meetings ?

Yes, if the club allows it, I understand there is no problem with insurance.

Not allowed at BRCA 10th Off road National and Regional level, rule states "max of 6 C type cells" needs to be changed and samples submitted to the electric board for approval.

you charge at the 1c rating so for a 4200 lipo you would charge at 4.2 etc.

lipo chargers work differently to nimh and you cannot "run all day on one pack" a good charger will charge the pack in 1 hour irrespective of the amount used so for example your 5000 lipo is used in a race and 2500 is used, you recharge at 5 amps theoretically it will be charged in 30mins, in reality it will take an hour, by the time you have finished marshalling etc there isn't an hour left. as for punch and power, you can discharge the latest lipo cells at 30c, so if your using a 5000mah then you can pull 150 amps, however if you exceed that 30c rate the duration crashes it will supply the extra ampage just not for very long.

no more care than nimh is needed. cost is cheaper overal as they dont loose performance
we have been testing in d4 and b4, adding weight helped, but im sure somone will find the sweet spot with a lighter car
hell:o please dont charge them at 20c a 5000mah pack would mean charging at 100 amps!!!!!!!!! charge rate of 2c is the max!

punch stays capacity drops, nope you have seen by prototype lipo cells with no hard case and my big accidents at worksop, no damage. nope trakpower ohave been amazed at how long packs are lasting in cars, as we use em a bit and top em up, they were looking at helicpoters where they do a full charge/discharge at full load. rcracehat has a pack with well over 100 charges and its still the same as new and was only recently balanced, when it was it took a few minuites to pull it back into balance.
insurance and use under the BRCA is fine, just not at sanctined meetings that dont allow them
ie there meetings that say only 6 cell they can not be used, any other meeting that wants to allow them can do and is covered by the brca
TC have allowed them in the uk

as i understand the brca will have a foot print, no hieght or capacity size, and they must be in a hard case. i dont believe they will mention stick only

:) Thanks Mark. I am grateful for the loan of the cells, mine still haven't arrived! But i did know some of the answers, its just good to have them in black & white on this forum for all to know.

P.S. email me some pictures! ;)

drop me ur email
if you want a pack to use you can have one posted or take one at worksop!! give it back on finals day
got some to spare

I have 2 orion lipo's and one trackpower, I use them in my touring car,buggy and in my starter box for my 1/8th scale.Probably the best money i have spent on anything for my rc's in a couple of years. The bit i like the most with them is they don't discharge when not used for a week or two.The sooner we are able to race in all brca classes with lipo's the better:D

.The sooner we are able to race in all brca classes with lipo's the better:D[/quote]


i agree!! the price can only come down on lipo's or do i mean go up when everyone starts using them, then cells will be cheap. i mean most racers have at least 4 packs of cells when they race = around £180 so i dont think we are going to get away with racing with a couple of packs of lipo's that retail at around £50 no no to easy, in time these will be crap you will have to spend £90 a pop to have any sort of relability. the Manufacturers know this, more time on the track less time in the pits = a much bigger premuim :mad:

the brca are capping price at around 70 or 80 i believe,

I thought, if your region allowed, you could run LiPo at a regional too, just like Brushless.

Not in 10th off road, regionals run to the same rules as nationals.

sorry but that can not be true

brushless was allowed at regionals before nationals, and i see no tyre rules for regionals, so regionals can not run to the same rules as nationals.
im of the understanding its down to the discgretion on the region!
the 2008 battery rules will apply to nationals and not regional.brca sanctioned meeting in TC so presume off road will be the same

Certain things are down to the discression of the region, but Lipo is no one of them. Lipo will no be allowed at this years regionals.

G

Must admit I do not fully understand it, but my answer was aimed at Lipo's and batteries not motors & tyres as that is what we are discussing. Here is a post from another thread on this subject, its a copy of a reply to a question I put to Jim Spencer:


Here is the (edited) reply I had from Jim Spencer

" Hi, Ok first off we're only taking about 1/10 Off Road Regionals, as they're the only class to run regional racing under the control of the full section commitee.

So the answer to your question is 'No' as the 1/10 Off Road rules don't allow LiPo's for any of their sanctioned events.

Any other sort of 'regional' event such as TORC or STCC from the touring car world then it's their choice.

Homologation works like this
When a section passes the rules for a new class it can - if it wishes - ask the Electric Board to draw up a homologation list (Bikes didn't bother) and the Touring Car section may well yet do so they're busy discussing that bit.
Assuming they do the E.B. would then contact the manufacturers asking for product to be supplied. (I suggested that a "vested interest" may propose & supply a sample-JCJC)

So in essence :-
No class uses them = no list.
1 class uses them = maybe a list > if they want one.
Get to a couple of classes and you'll definatly get a list.

The drivers in the classes need to vote in their use at Nationals to generate the info folks seem to want - almost as a comfort zone?

Hope this helps Jim -Jim Spencer "


Thread on RaceChat tucked away in the BRCA General Q&A forum,

http://www.rcracechat.com/vb/showthread.php?t=38852

http://www.rcracechat.com/vb/showthread.php?t=38896


I for one would like the chance to play with Lipo's at regional level, as the only Nationals we seem to do are the Juniors & F3's then National level is of little interest to me, I suspect NiMh punch to be of more importance to top drivers anyway.

Having used Lipo last weekend, it is stupidly fast and over powers the car far too much, however I changed nothing except putting a Lipo in. I for one wouldn't mind Lipo been run at regionals, but as far as I can gather from reading the rules they are not allowed at any BRCA sanctioned events (incl. regionals) for 2008.

With a class of touring cars running it this year and ROAR's approval it will give the BRCA a chance to see what/how it works over the next year and give them a lot more information regarding allowing it next year and what the best regulations are. Let them do the testing and then we can adopt whats best.

At the end of the day it all depends on a proposal been put forward and enough RACER'S voting it in at the AGM, just like with all rules.

As far as I can gather there was no proposal made for the 2007 AGM to allow Lipo at any BRCA events for 2008 so the one's who want it only have themselves to blame.

my mistake got the santioned bit the wrong way round.

Tom keep it till worksop finals weekend if you want to!!

Cheers

It might be overpowered and far too fast but it's a lot of fun :D

Is there a prefered make of lipo to some people or are they all very much similar to each other performance wise?

Looking at the Lipo "power outut" numbers.....20C 30C burst etc

For a layman in real terms whats the math ? please,

Say 5000mAh, would 20C be what, and how much would say a 10 double or 5.5 brushless draw? and the esc & servo or is that insignificant.

the c rating is the amps the pack can deliver trakpower 4900 is rated at 25C 122.5 Amp continuous, 30C 150 Amp max acceleration 50 nearly 250 Amp spikes
i doubt very much you will pull 122 amps continuous, the higher the c the more punch

Cheers Mark, so our 5.5Brushless would be no problem on the trakpower, just need a protector.

What is needed is a true scientific head to head test during 2008. The new homologated NiMH cells Versus the latest Lithium Polymer offerings. Personally I dont think they (LiIon Polymer) should be allowed unless the products:

(1) Contain cells which carry UL1642 recognition
(2) Have on board protection circuit for over voltage (over charge) and under voltage (over discrage).
(3) Are hard cased in at least 1.50mm of UL94V-0 plastic.

This would make them 'proper' products, not cells linked together and which rely on the user to (i) balance them (ii) correctly set their charger so they dont dangerously over charge them (iii) Ruin them by over discharging them.

If you were asked to do these things with your laptop battery you would laugh!

Neil

MAH divided by 1000 = 1c. So a 5000mah is 5ah per 1C

Therefore 20c 5000mah packs = 5 x 20c = 100 amp continuous for 1hr = 100ah
5000mah 30c = 5 x 30c = 150 amp /1hr

Its funny how I can understand maths, but then minutes later I re-read what I write and it baffles me.... :wtf:

So, mark, so figures you state for 4900mah packs were actually 5000mah packs? or am I wrong with my maths? LOL. Im confused

Chris

This would be good for all of us, makes them idiot-proof. But I take it the tourers have not adopted this? if not, does this mean if we take on Lipo in 2009 we have to go with a single homoligation list used by tourers too, i.e. is it too late for BRCA to enforce this for 2009 and so for the manufacturers to implement it in the pack. (... lots of what if's in there...)

Chris did the X-Factory Math :rolleyes:

LOL, I so nearly said something too, but it was just too predictable!! ha ha

haha ! :D

neil i know you know your stuff, but if sence is used there fine, doing what you suggest would only do one more thing, make them more expensive.
i used the text off trakpowers site!!
tourers are not having a pack list, nor are they having capacity cell counts etc
from what i have been told, there will be a max width and length, 7.4 volt max, and hard cased and thats about ur lot.
i know for fact that less lipo's have gone wrong this year, than nimh have had go wrong, and we have no saftey precautions for nimh