Lipo Cells

[Garrypd160]

Now I know that they are not BRCA legal but would anyone mind if I run Lipo cells at FRCC, in order for people to evaluate there performance etc?

[big si]

if you did a search of the forum you would have found this


http://www.falkirkrcc.co.uk/forums/showthread.php?t=825&highlight=lipo

[Garrypd160]

I've seen that post, but since I'm not competing in your club championship, and it doesn't affect anyone, I thought people might like to see one running to give them a better idea on them before next years AGM ;-)

[big si]

read the full thread though garry. i got shot down for suggesting it.
personally i dont see the problem with them and would love to use them

[Garrypd160]

I have read it through Simon, and dont worry about getting shot down (u get used to it after a while). There wasn't a definitive answer in the thread. If people dont want me to race with it, I dont mind. I can always run it in practice and anyone interested can have a look.

I have just got one, as Ayr club members would like to see one running before saying yes or no to it (and I can always use it for practice everywhere else). I just thought that, as Scotlands largest club, you might want some 'real' info on it, instead of forum gossip/hearsay.

Hopefully the Falkirk Committee members will get word of this post and give a definitive yes or no to using it.

[big si]

im all for seeing it go especially if linked up to brushless

[Garrypd160]

Well that could easily be arranged :-P

[ballsie]

I'm not competing in your club championship,

I think that's the most important point. I can see why others would be bothered if you were in our championship Garry but I can't see any harm in you using them for the occassional run at FRCC.

I for one would love to see how they perform.

We probably need a concensus of opinion though.

[big si]

ballsie can you start a poll on this to see what kind of responce there is?

[big si]

garry do you run stick or wheel???

[Garrypd160]

Stick, but If anyone with a wheel tranny wants a go, then I can sort something out.

[big si]

i run wheel with spektrum and would love a go to see how it feels

do you run spektrum?

[Garrypd160]

Yeh I run Spektrum, so would be no problem for you to have a go.

[Alex Lindsay]

In order that members may get the facts Garry, maybe you should post here the ins and outs of Lipos with respect to cost, life, charging, expected performance, safe discharging, and generally how to use these batteries.

We respect that some of these may be your views, but if you have a website that quantifies these points, then maybe you could post up here for all to read. Also and most importantly, on any safety aspects that have been found, good or bad.

I know these have been in use for some time now in RC bikes and they must get more abuse in the long run in bikes than in cars.

[big si]

superb I'm very interested to see how the lower turn brushless and lipo perform

[big si]

here is a review on the trak-power lipo from the OOPLE site that you can all read and see what someone who has used them thinks

http://www.oople.com/rc/photos/reviewtrakpowerlipo/

[Garrypd160]

In order that members may get the facts Garry, maybe you should post here the ins and outs of Lipos with respect to cost, life, charging, expected performance, safe discharging, and generally how to use these batteries.

We respect that some of these may be your views, but if you have a website that quantifies these points, then maybe you could post up here for all to read. Also and most importantly, on any safety aspects that have been found, good or bad.

I know these have been in use for some time now in RC bikes and they must get more abuse in the long run in bikes than in cars.


So far, most of the stuff I know, is comng from other people, manufacturers websites and some power tool based knowledge, but here goes:

Cost - A single Lipo cell (actually two cells in a case) for use in a car starts at £80, up to £95 for car compatible Lipos. £80 will get you a 3200mAh Lipo that is designed to fit in a car properly and comes fully encased with a hard case. This is the one I plan to run. Although it is a 3200mAh cell, it gives the same duration as the current 4200 ni-mh cells.

Lifetime - the lifetime of the cells remains to be seen but they are advertised as being able to last almost 4 times as long as ni-mh cells, and I know that the Hilti power tools we use have lasted longer since Lipos replaced ni-mh cells.

Charging - You must have a Lipo charger. Using a ni-mh or nicad charger WILL cause the lipos to catch fire. There is a lipo exclusive charger on the market for £40. There is no need to discharge or equalise lipo cells, although you can now balance them while you charge (similar to equalising, but on the way up not on the way down). You must never allow a lipo to go below 6v. My speedo has a built in cutout for this, but a seperate cut out can be purchased for around £15. I, personally would not allow anyone to run without one. You can charge a Lipo cell anytime you like without the need to repeak as they dont lose charge in the same way as ni-mh do, so you could charge the night before racing if you are short on time.

The performance of a lipo is reported to be on par with the new breed of 4200 cells, but with no drop off over its discharge period, and with half the weight of a set of ni-mh cells.

My personal opinion at the moment, if clubs were to allow the trial ru of Lipo cells, that they limit it to only the hard cased Lipos as these are less liable to get damaged during racing (again which can cause fire)

There are a lot of stories going around about lipo catching fire if you look at them too hard etc, but there are now the same stories regarding 4200s. I would think that used in the correct manner, there will be very little chance of anything going wrong with them. The 1:5 scale bikes having been using them with no reported problems and they dont use the hard cases, and are subject to more abuse than a car, so I dont think there will be any huge problems running them in a car.

[ballsie]

Poll added guys.

Remember that Garry isn't an FRCC member and this wouldn't contribute to the Championships.

Cheers.

[big si]

very good review Garry I'm all for them. the new breed of IB cells are being referred to as the firecrackers and have been proved to be more volatile than lipo.

cell manufacturers don't recommend we charge NI-MH at the 4 and 5 amps we do so we are all mistreating our cells myself included whereas LIPO can be charged at 7 amps with no problem (dewalt power tools wouldn't risk a customers life by saying this) to me lipo is the future and are no more dangerous than any other power source on the market.

[Garrypd160]

Yeh most of the car Lipo cells have a 2C charging limit. SO for a 3200 you can charge at 3200x2C - 6.4Amps. For a 4800 cell - You can charge at 9.6Amps if necessary. The only difference this makes is how quickly they will charge. A lipo charged at 1amp, in theory, will be as quick as a lipo charged at 10 amps.

[big si]

yip there is no voltage change at all so are more stable than other cells on the market

[Garrypd160]

Some extra info from Team Orion (I got their Lipo cell)

Kokam (manufacturer) certifies a charge rate of 1C (1A for every 100mAh, i.e. 3.2A for 3200mAh battery). The batteries are known to be capable of accepting 2C or even 3C charge rate. However, this will reduce the useful life cycle. Therefore, Kokam and Team Orion do not recommend using a higher charge rate

Lipo Packs must never be discharged after use. Cut off voltage per cell is 2.7v, so a speedo cut off of 6.0v is recommended.

There are no restrictions on the amount of times a cell can be used in one day.

The battery can be stored for 6 months and will lose no more than 10% of its original capacity, dependant on storage temperature.

Do lipo batteries explode if damaged or overcharged?
To our knowledge, any rechargeable battery that is currently on the market has a risk of explosion, fire, and a smoke emission if treated improperly. You are aware the a mobile phone has a lipo battery, but you are not afraid to continue using it because you use the recommended equipment and methods only, right? Kokam and Team Orion have done everything possible to minimise the risk when the battery is abused or damaged.

The team orion 4800 pack weighs 258g, the 3200pack weighs 198g, while an assembled NIMH pack weighs 401g

[ballsie]

Have you got the big platinum one or the carbon 3200?

[Garrypd160]

The carbon 3200. The cost between the two is negligible, but the 3200 fits in the car better and is their advertised 'direct equivalent' to a 4200NIMH cell.

If it all goes well, and its allowed at a few places, I would be keen to get the big 4800 cell, purely because it allows longer runtimes. With the 4800 and brushless stock, I cld run all night on one charge :shock:

[ballsie]

With the 4800 and brushless stock, I cld run all night on one charge :shock:

:razz:

[Alex Lindsay]

Thanks for that Garry, quite a comprehensive report.

I am starting to understand their usefulness better now. How long will the 3200 run for in terms of racing with the brushless all night? Will it require charging to cover the four races?

[Garrypd160]

I'm not 100% sure yet alex. The instructions say it has similar run times to the newest 4200 nimh cells, so it would probably just about cover 4 races with the brushless, but would be a safer to top it up I would expect.

[big si]

well i for one was very impressed with lipo. thanks to garry for the demo and letting me have a shot.

overall very punchy but no quicker in a straight line than my car all in all i for one am all for them and will be proposing them at the EGM

[Garrypd160]

Just a quick update. Have run the lipo a few times now. With the Novak 13.5 stock brushless I can run all night on one charge. To fully charge it from empty at the recommended 1C then it takes 65minutes (approx). After a five minute run with a 19t it takes approx 15mins to top it up to full. I have been in contact with team orion and they are about to release new information regarding charging at 2C, which will half those charge times.

The good thing is you can charge it a week in advance and it never loses any voltage.

At the same time as I got the Lipo, I got 6 sets of IB4200 WCs so I could compare. 3 sets of matched and 3 sets of unmatched. I haven't had enough cycles out of them yet to fully compare but I will post the data in the next couple of weeks. The one thing i will say, after spending the best part of 3 hours soldering up all the 4200s, 1 set have had to be sent back due to a dead cell, and one other set seem to have a duff cell too. Now I might just be unlucky, but I have heard of other reports of this, and IMO is just one more reason that Lipo cells are the way forward.

[Malcolm Williams]

Don't know if this is any good for you guys, but check them out chea**** cells and charger.

http://www.vapextech.co.uk/acatalog/copy_of_copy_of_High_Power_Model_Control_Batteries .html

Could save you some money on the charger I would think if not the batteries (dont think they are BRCA though).

Malky:wink:

[big si]

malky these are non protected (not in a hard case) therefor not a good idea. i will say to anyone interested in these DO NOT BUY THEM if lipo cells are not in a hard case they are unsafe for our purposes as they are soft cells and easily punctured which is what can cause them to burst into flames

[KC]

Garry, I have had bother with dead cells in my IB4200 WC packs also.
I have replaced 4 cells in 3 different packs.

I just got a set of East Power "Firecrackers" to try out.
Hopefully they wont be as temperamental!

After the shot I had of your car with the Lipo pack on carpet, I have been converted!

The sooner they become legal, the better!

[Malcolm Williams]

Point taken Si, did not go that deep in investigating them, thought the charger was of more interest than the cells though M8
Malky