Li-PO advice?

[chris68nufc]

Im hoping to try li-po in my bj4 after seeing the b44 on oople recently with lipos installed in it.Looked great!. I have been thinking about this for a while but not sure if it will suit me for club racing. My problem is that i feel that my decent cells are getting hammered and it is a struggle to get them charged after work for racing at 6.30pm.
A few questions.
1. How many lipos will i need for 4 rounds and a final. Normally about 20 mins between rounds(smallish club!)
2. Can i use my Much-More charger Platinum edition to charge them?
3.What else will i need for balancing?
4.Do you just top up the lipos after a race?
5.Do we yet know if lipo performance is affected with this kind of use?

Any suggestions will be much appreciated.

Cheers

[sosidge]

2. Can i use my Much-More charger Platinum edition to charge them?


It will charge them Chris but only at 1A so will take a LONG time (you have the Cell Master, right?).

The Much-More Silent Charger is their best one for Lipo, it will charge at up to 6A.

[Chrislong]

Im hoping to try li-po in my bj4 after seeing the b44 on oople recently with lipos installed in it.Looked great!. I have been thinking about this for a while but not sure if it will suit me for club racing. My problem is that i feel that my decent cells are getting hammered and it is a struggle to get them charged after work for racing at 6.30pm.
A few questions.
1. How many lipos will i need for 4 rounds and a final. Normally about 20 mins between rounds(smallish club!)
2. Can i use my Much-More charger Platinum edition to charge them?
3.What else will i need for balancing?
4.Do you just top up the lipos after a race?
5.Do we yet know if lipo performance is affected with this kind of use?

Any suggestions will be much appreciated.

Cheers

I'll start with leting you know, ive only run Lipo once, borrowed cells of Mark Christopher (thanks MC!) and was astonished at just how easy it makes racing again - no need to molly-coddle them like we are with Intellects.

Also, bare in mind, if you are running something like a 5.5 with Nimhs, then with Lipo you'll need a 6.5 and its still likely to be faster. :thumbsup:

1. Likely just 1 pack
2. Sausages
3. Less beer, good shoes, maybe a long pole.
4. Yes, start the day with the packs charged, go and race (or practice for 5 minutes (no more)) and go back to the pits, put on charge > go and marshall. The cells will be fine treated like this, no need to discharge. Its advised to run a voltage cut on the ESC, but not essential if you have faith in your ability to not dump the cells in the car (this is baaaad, its like crossing the streams!).
5. No affect known of yet, Mark Christopher is more experienced to know, but TomC ran a pack of his which had seen months of regular use without balancing, and the performance from them was still amazing - no different to newer ones (of the same make/spec) in my car.

Edit:
3. There is a gizmo which plugs into the cells and then your charger plugs into the gizmo, and so continuosly balances while charging/discharging. Or leave the gizmo plugged in on its own to slowly balance the cells.... but this seems less important than doing it with Nimhs, time will tell if there is a risk of damage through not balancing.... Mark Christopher will remember the name of this gizmo, it was something he was showing me last Sunday.

Chris

[Chequered Flag Racing]

I ran my 3700mah lipo all day @ the Catherine Cookson Classic in my RC10T4 with a Mamba 7700k motor. Loaned it out during the day to Richard Lowe and a few others to run to. All I did was recharge it on my lipo enabled Pro-Trak.

Spoke to Phil on the day about re-balancing and those that he has from testing and writing the software for the Pro-Trak haven't been near a balancer and he still had loads of go from the cells in a B4 with a 19t motor.

I have a Flight Power balancer that needs to be plugged in between charger & lipo. Some chargers have the balancing function built in.

[rob8246]

I have said before that in my opinion LiPos are the future but im not convinced the cars are quite ready for them yet??
What i mean by that is the cars were designed with the weight of 6 cells in whatever config they needed to be.
LiPo's are of course very light so additional weight would need to be added to the cars in places it was not designed for.
Is this a big problem?? I dont know but im sure its another valid talking point.

As for your question, PM me and I will let you know what you need.

RR.

[Chequered Flag Racing]

Edit:
3. There is a gizmo which plugs into the cells and then your charger plugs into the gizmo, and so continuosly balances while charging/discharging. Or leave the gizmo plugged in on its own to slowly balance the cells.... but this seems less important than doing it with Nimhs, time will tell if there is a risk of damage through not balancing.... Mark Christopher will remember the name of this gizmo, it was something he was showing me last Sunday.

Chris

the gizmo @ work (http://www.flightpower.ca/images/V-Balance_charging.jpg) other wise known as a FLIGHTPOWER V BALANCER

[chris68nufc]

Chris. Didnt get number 2 response but im tired so might be missing something.
Im defo up for trying them after seeing them inside a split 3x3 cell layout but wanted to get a bit more clued up.
Cheers.

[Chrislong]

LiPo's are of course very light so additional weight would need to be added to the cars in places it was not designed for.

True, Lipo's are lighter, but in my opinion this just means you can select where the weight is added, or choose to allow the car to run light if it is far over weight with Nimh in. I don't consider this an issue of any type, id consider it a benefit.

The only issue with some cars, is that stick packs won't work, and although saddle is availabe - when/if the BRCA make them legal (when the time comes) then id presume the likelyhood is it will be stick packs only, hard cased, to a set dimension. While any of us can buy and run saddle Lipos at club meetings now, personally id like to run what I may be running in 12/24 months time at nationals. (big presumption, but I hope it happens)

[Chrislong]

Chris. Didnt get number 2 response but im tired so might be missing something.
Im defo up for trying them after seeing them inside a split 3x3 cell layout but wanted to get a bit more clued up.
Cheers.

Ah, LOL, what I meant is Sosidge answerred it - as I don't know anything about those chargers. I used a Pulsar 3, charging at 5.5A.

[chris68nufc]

Thats ok Chris. I was sitting thinking everything witty about sausages and chargers and i thought you had me there.LOL!

[craigosh]

Been running a trakpower in the b4 since july and its great. No maintainence involved really, always comes off cool, let it cool some more while i marshall then stick it back on charge at 5amps. I have the trakpower balancer connected to an Orion flight charger and it just takes care of the pack as it goes.

Weight wise, i tryed putting in the weight back in, tried a few different places, but found that the car runs better without the added weight. Just use a lighter oil and spring, or even just a lighter spring seemed to work. I use Silver/Green outdoors as opposed to blue/silver.

With the 6.5 brushless it can be a handful but its super quick on the straight :D

[mark christopher]

the bit chris talks about is the trakpower balancer www.trakpower.co.uk (http://www.trakpower.co.uk) same as flightpower but gold in colour

http://www.trakpower.com/Images/VBal.jpg
a balancer is good BUT not a necessity, if you find some one with one ask them to balance your cells ( will take 5 mins max) every few months would be enough (though as allways if you can afford one get one as its a good investment)
the trakpower balancer does have some saftey features which makes them good for new users as its an added saftey feature

just topping them up does actuatlly increase thier life, as two half top up's is equivalent to one full discharge and charge

so a 5000 pack having 1500 taken out is using less that a 1/4 of one cycle

trakpower were amazed at how long car pacjks were lasting as they were comparing them to planes, where the plane do a full dis/charge cycle we do 5 mins and top up

[mobile chicane]

cool I was going to post a thread just like this as some of my 4200's are dieing so I can use my ripmax elite competition charger ?

the instructions say a charge current of 0.1 to 8A on li-po charge current but they also say 1C limited and as 7.4 v lipos are 2 cell this is a bit of a worry as the blurb in the manual mentions nothing else about the 1 cell limit.

I suspect I will pobably get 2 lipos of the saddle pack style and a balancer as they seem to be on ebay already

http://cgi.ebay.co.uk/TrakPower-Lipo-V-Balancer_W0QQitemZ120216892294QQihZ002QQcategoryZ3 4063QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

safe ebay linky.


I just hope lipo become legal as the amount of mucking about with cells I do seems never ending :eh?:

[mark christopher]

your charger is the same as one of mine, the robitronics overloader.
so yes its fine, if your pack is a 4900 then it will automatically set the charge rate at 1C which will be 4.9 amps
trakpowers pack can be charged at up to 2C though no advantage to go that high unless your stuck for time or want to shorten thier life.
if you wantto charge at 5 amps just tell your charger its a 5000mah pack
the balancers are available from most good model shops including MBmodels in leeds

[JCJC]

but they also say 1C limited and as 7.4 v lipos are 2 cell this is a bit of a worry as the blurb in the manual mentions nothing else about the 1 cell limit. :eh?:

Giles, unless I am mistaken you are assuming 1C is one cell, it is to do with the battery power, 3700's would charge at 3.7Amps, 4200's at 4.2 etc.. so your 4900 trackpower would charge at 4.9Amps

My understanding is you do not have to balance very often, but must watch the voltage, must not fall below about 6volts or the battery is a goner.

[JCJC]

The little square connectors with little pins, that a lot of chargers & batteries have for balancing - do they have a name, type ? can I buy them from someone like maplins?

[mobile chicane]

Giles, unless I am mistaken you are assuming 1C is one cell, it is to do with the battery power, 3700's would charge at 3.7Amps, 4200's at 4.2 etc.. so your 4900 trackpower would charge at 4.9Amps

My understanding is you do not have to balance very often, but must watch the voltage, must not fall below about 6volts or the battery is a goner.


aaaah thanks for clearing that up I did wonder