Lipo Batteries (yes or no)

codieskid · #1 15-09-2006

Just been reading about Lipo batteries here: http://www.teamorion.com/Products/Batteries/Lipo

Has anyone ever used any of these, if so are they any good and what are the advantages/disadvantges. They sound pretty good but will they fit in a zx-5 and what modifications would need to be made to get them to fit?

so are they lipo, go go or a lipo, no no? (sorry that was terrible)

Cheers

Trev

Rob Fitzgerald · #2 15-09-2006

This weekend I am going to be racing my Losi 2WD XXXCR with a Mamba Max brushless system in it powered by a TrakPower 4900 mah LiPo

I just tried it out in the street - VERY VERY silly and more than a little addictive.

The plan is to use just the one LiPo pack and just keep topping it up for each race. That's how I see LiPo could be a great thing for RC racing. Just to make it worse this is a Heads Up meeting (sort of Reedy style) so I will have to do 2runs on one charge at some point

- 6 races in total !

Can you imagine a harder real world race test than that ?

codieskid · #3 15-09-2006

Keep us posted on how you get on, be interested to see how it copes.

jimmy · #4 15-09-2006

Should fit alright, you might have to shave a couple of "nodules" ( I like that word) off the battery bar though on the zx5.

The orion pack is just a nicely packaged pair of 3.6v cells. You can get the actual cells naked which is what I have driven before. They are a lot lighter than a normal battery pack (the orion pack is heavier of course) seemed ok to me from a performance standpoint.

Rob Fitzgerald · #5 15-09-2006

The test is almost unfair - but if it survives this it will survive anything.

Imagine if it works out though - no motor maintenance and just topping up the same battery all day.

Thats a lot of free time to watch the racing, eating chips and talking crap with your mates

Sounds good to me

jimmy · #6 15-09-2006

Rob, do they need a cool down period ? or in fact do they get hot ? Just wondering is they are supposed to be 1 run a day packs or if they can really be abused - which would be great.

BenG · #7 15-09-2006

Quote:

Originally Posted by Rob Fitzgerald

Thats a lot of free time to watch the racing, eating chips and talking crap with your mates

Sounds good to me

all good except the crap talking bit

Rob Fitzgerald · #8 15-09-2006

They are quite happy for to try and break them - that's more or less why I have it - race it and hard.

I just tore it up and down the street for a few minutes (wheelies were good fun) and the motor was warmish bot no noticeable heat in the cells.

I will take it down the field later if I get time and see how it copes with the draggy grass.

No mention of a cool down period - I told their tech guys what I had planned and they said fine, go for it.

Obviously no one yet knows if I will be able to do 2 runs on one pack but the match races are 4 minutes so I am guessing I can.

This pack is rated for a 10 amp charge rate - yes TEN.

For arguments sake it will take 30 minutes to charge up to 80 ish % and then another 20 ish to top up - BUT - the voltage out is the same at 80% charge as a 100% charge so you don't need it 'peaked' as such.

Chrislong · #9 15-09-2006

Wow, impressed with the info so far Rob, sounds like the way forward. Although safety will be the deciding factor I am sure.

*Bang*

DCM · #10 15-09-2006

is it the gold ones Rob, as I understand, the harder you charge/use them, it realy drops the useable cycles on the cell. All great charging at 10A but it kills the cells.

Jim, I do beleive they do get warm, and need a little rest before charge, as like any cell, it is a chemical reactio producing the stored energy.

LiPo, if it is in a case, that surrounds and contains the cell and the undervoltage protector, plus maybe the balancer to, then great, if they are the ones the Heli guys use, then no. I think people misunderstan that a lot of LiPo cells are not rated for our power useage.

Rob, hope you are ballasting up the car though, as I STILL haven't seen a race test with a back to back, cell and LiPo but with the LiPo the same weight as the NiMH setup.

Rob Fitzgerald · #11 15-09-2006

I wont be ballasting the car up as I am an open race against 4WD cars so I already have my work cut out. My Losi is a bit porky anyway.

Yes Steve it's the gold one from TrakPower. They have done some hard testing and are just collating the data but it appears the high charge damage might not be what we assumed.

Re charging just used cells - I think the honest answer is that no one knows how they will work in cars used like this because no one (or very few) have actually tried it.

Remember we are not bashing here and a 5 minute race is onloy going to pull roughly half of the capacity out.

Anyway this is all theory - monday we will have some real race testing fact behind us.

DCM · #12 15-09-2006

Thats cool, I think LiPo will be the way of the future, it just needs, erm, toughening up and making secure so that dimwits won't stick them on their '30min riko charger' and sorts.

jimmy · #13 15-09-2006

Is the case around them partly for safety reasons ? This and the orion ones seem to have similar looking cases, normal cells dont have cases so whats the idea ?

bigred5765 · #14 15-09-2006

Quote:

Originally Posted by jimmy

Is the case around them partly for safety reasons ? This and the orion ones seem to have similar looking cases, normal cells dont have cases so whats the idea ?

its because they explode and set on fire:bom:
check it out death buy over charging
http://video.google.com/videoplay?do...60570423705609
and here buy physical damage
http://video.google.com/videoplay?do...o+battery+fire

Rob Fitzgerald · #15 15-09-2006

I think the case does two jobs (Colin Chapman would be proud)

It makes it easy to mount it in a RC car and it gives it some impact protection as LiPo isn't really keen on that.

Those videos actually p**s me off a bit - get a NiMh and connect it to the mains and see what happens. Smoke while filling the tank of your FG Marder and see how you get on.

If you are stupid you will get hurt - if you are stupid enough to wrongly charge a LiPo then chances are you suffocated yourself in the bag it came in on the way home on the bus anyway

jimmy · #16 15-09-2006

hahaha good point rob.

Yea I can see the impact protection thing, are they quite soft or something ? the ones Ive seen / used before weren't in a case and didnt seem very robust.. If they blow after getting punctured or something then yea - box that bugger!

I have seen the latest normal cells blow up and it wasnt pretty - in fact it was downright scary, but there is more hype and rumours spread about lipo since its new.

albertobdq · #17 15-09-2006

Hi everybody.

Here is Spain we had 2 cases of burning lipo, just in the pits while charging with proper chargers. The risk exist and it's bigger than risk you take while using Ni-MH.

Concerning their weight, well, if you are using a chasis layout with asimetrical distribution for batteries you'll have an issue with your weight distribution. Lipos are 100+ gr. lighter than Ni-MH, it's a huge difference for 1.5kg car.

Off course you'll have more power due to higher voltage and running time is also longer, but you'll need some device to switch off the car if voltage drops.

Ah, off course lipos are more expensive!

DCM · #18 15-09-2006

I think, for the more level headed of us, the LiPo gives no warning of it going pop, and when it goes, instead of just a bang (and in some cases, explosion) with a normal sub C cell, the LiPo will cell and ignite.

I know the Kokam cells are VERY good, and have video proof of the cell still stable whilst and AFTER it has been drilled.

Me, I shall wait I think, and see how things pan out before I go down the LiPo route.

bigred5765 · #19 15-09-2006

I used to fly electric flight and trust me, they don't need to be abused to explode, and when they go, boy do they go. Like plane in flight one minute, next no plane, no nothing, just flames.

andys · #20 15-09-2006

Quote:

Originally Posted by bigred5765

i use to fly electric flight and trust me they dont need to be abused to explode, and when they go boy do they go. like plain in flight one minuet next no plain no nothing just flames

That is genuinely the first post on this forum that has actually made me laugh outloud. And the spelling just added to it ! I wonder if the same thing would happen in a buggy ??

At least with normal cells, when they go pop in your car, you don't lose the whole car...... with lipo, you may never see it again.

Nice one.