SamUK

iTrader: (1)

Just bought 4 Lipo Batteries and HPi Vorza RC (will be here next week)

The batteries i bought are (Cost £65 each)

TrakPower Lipo 2S 7.4v 6200mAH 50C

other batteries i am thinking of buying as they are allot cheaper are: (£30 each)

Trunigy Lipo 2S 7.4V 5000mAH 30C

Now i know the mAH is the run time and C is the discharge rate, having never used a electric RC before.

Can someone tell me if there will be a noticeable difference between the two? is the more expensive one a better brand perhaps?

I needed some more and not sure which ones to order.



Other question is if i charge all the Lip batteries and do not use them for 2 months, do they loose charge sitting around?

EddScott

http://www.youtube.com/watch?v=yWixn...eature=related

This might help.

I think you'd feel more punch from the 50c battery.

I bought two set of the Turnigy you mention for my SCX10 crawler. I bought these for the crawler as the high C rating wouldn't really be useful in a crawler with a 55t motor.

I have to say I'm not completely at 100% with Lipos myself.

Regarding storage, AFAIK they are not as fussy as Nimh cells and can be left part or full charged. I've got a Turnigy charger that has a storage charge function. I don't use my cars during the winter so store the cells in a charging bag.

The big issue with Lipo cells is not to run them flat. I think good practice is to have a Lipo alarm fitted. I haven't bothered on the crawler because even after an hour the 5000 still have loads left.

Dr Hu

Well I fly electric model planes - and recent change up from 20C 2000mah lipo's up to 25C 2200mah made a huge performance difference......

The 2000 to 2200mah is the biggest performance difference, you are putting a stonger output battery on - in your case going from a 6200 to 5000 will be very noticeable in speed IMHO.

That 6200mah 50C is one HELL of battery - you sure its not a Prius your racing?
The C rating is all about how quickly it can get the power out of the battery without damaging it.

Lipos tend to keep there charge for very long periods, in fact its recommended you dont leave a fully charged lipo in storage - i read somewhere charge it to around 50% if you are laying them up for the winter.

Be careful about charing & discharging them, if you over charge them or over extend their discharge (really bad!) they will puff & blow a cell.... very easy to do.

My model plane it has a pre-set lipo cut-off that warns you you are at low voltage - over fly it at your peril as it will cost you a battery.

You will read all sorts of horror stories about lipos & how dangerous they are, but as long as you are careful they are fine.

SamUK

iTrader: (1)

This is the one I ordered from the US: http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXASTZ

This is the one in the UK: http://www.ebay.co.uk/itm/3208032938...84.m1423.l2648

When I say for storage, I mean I want to charge them today and use the car say next week or the week after – as opposed to long term storage,

SamUK

iTrader: (1)

I have been corrected the motor of the RC can only draw 120amps.

so if one battery is 310amps, the left over 190amps allows for the extra run time

billythekid

I fly elecric planes on 11.1v. I find there is defo a price v performance issue with Li Po cells these days - although they are a lot cheaper. My first battery packs were £200+ and now, the same pack is about £50-£100 depending on make.

The bottom line is get the highest C rating you can for the money you are willing to spend. I tend to fly on 11.1v / 5a/h / 30c - they cost me about £50 each. My plane is heavy though, and carries a lot of kit (other batteries, GPS, camera, video link etc).

Its currently in storage though, due to too many bad crashes. I am looking at moving all the elecronics out of it into another air frame next year.

ALi-B

iTrader: (1)

The other thing to be wary of is ensuring the batteries being actually of their rated value/capacities.

Their rated values could be miles away from their real-world ratings/capcity. Same with durability. In the end its about the brand and their reputation - some lesser brands pushing the biggest rated mAH cells sometimes aren't any better than a quality brand with more conservative capacity ratings.

Unfortunately the olny way you are going to know if they are what they say on the tin is to test them or get feedback off other users.

mart360

One thing to be aware of with lipo batterys....

They give full power until they are discharged, no gradual running down like niccad / nimh

However once they are discharged... ie the item wont run/ fly. dont try to carry on.. Lipo's get very hissy about being run in a discharged state.. and can go pop!!!

Also use the dedicated charger they came with, they are very fussy about being charged correctly (but you allready know that dont you )


Mart

SamUK

iTrader: (1)

lol..

i am new to this, i have spent £700 so far, and i still aint got the car! Ariving next week from the US, so i want to be ready for it..

Only thing i am missing is the charger and the sack thing!

Now i have been told to get this charger, as its good value for money and will work well: though not sure how good this instructions would be, as there are methods that need to follow or i will distry the batteries..

http://www.ebay.co.uk/itm/iMAX-B6-RC...ht_6187wt_1164

Other charger option was this as recommended by Model Sport

http://www.modelsport.co.uk/core-rc-...roducts/365880


The sack: http://www.modelsport.co.uk/overland...products/38313

vindaloo

Try these maybe...
http://www.dealextreme.com/c/batteri...sort=relevance

I've not used them for major stuff, just a couple of CREE/SSC torches and a Magicshine bike light. Worth checking feedback/reviews for any stuff you consider buying... To the point that I wouldn't risk £50 on something too "new" to have been reviewed.

Also, they ship from China/HK. Due to "electronic" items getting scanned and/or delayed in customs last year (terrorist threats etc) my bro's bike lights turned up late January! Still, even without extra delays, now might be too late to get stuff before the holidays.

J.