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View Full Version : Newbie help - what batteries and Charger - i'm so confused!!!



zackmitchell
15-10-2009, 11:18 AM
Hi Guys,

Looking at getting back into this r/c lark after playing around as a kid etc.

Planning on getting MI3.5 and running it with 10.5 brushless, mainly indoors but will also visit snetterton as this is 15 mins away.

The question is what batteries do i go for and which charger, i am used to 7.2 stick packs and now there is this whole lipo market, before i didnt even know about the whole cycling, equalizing of cells etc.

Been reading many post on here etc and now in a muddle as to what i want / need.

The whole lipo lark, seams to be a much better alternative than cells as they seam less work but would i notice the difference in power output?

And then what size lipo's do i need / go for?

Any help would be much appreciated!!!!!!

mad-wolfie
15-10-2009, 12:31 PM
Any help would be much appreciated!!!!!!


LiPo is the way of the future & what a lot of the more "serious" racers are going for, however still quite expensive when compared to using other batteries & the chargers aren't as cheap as those for regular cells plus they need a unique charger. You do get a bit more punch from a LiPo & they don't tend to go flat as quick so don't lose power on the last few laps of a race, but there is a bit of repsonsibility involved in using LiPo.

Stickpacks that you are used to are only really used on the more entry spec cars these days, although still widely used in Japan. the chassis for the Mi3 will only take saddles (side by side cells - not stacked line in a stickpack) or can be adapted for Lipo's.. - some Lipo's have ridges to emulate the slots for saddle packs. Saddle pack batteries you could make yourself by stripping down sticks & converting them.. this will be fine if you don't want to go down the LiPo route or you can buy the individual cells & build your own.

Technically speaking any car that will take a Lipo should take a stickpack but i wouldn't advise using Stickpacks unless you had a £100 tamiya or an RTR. Also if running a 10.5 brushless i wouldn't advice using Tamiya type connecting plugs that you always get on sticks (& most electrics when you buy them) - they tend to melt!

JCJC
15-10-2009, 06:14 PM
Lipo charger less than £100 (would advise getting one that will 'balance' - charge both cells to same voltage). Saddle lipos less than £75, BRCA approved, most have 4mm female connectors. We can manage a days racing on one set of lipo saddles, 2 sets is comfortable. Ours are 4400's and 30C and used in a buggy with 5.5 turn brushless (9 turn equ brushed?), no problems with lack of power, and as I said, race 5min, slap on charge twix rounds & race again. we used to take 6 packs of cells for a days racing so lipo for us has been great this year, and expect to use same batteries next year.

If you are going to race at a local club pop down and see what people are running.

emtee
15-10-2009, 08:49 PM
I changed to lipo last year and have never looked back... Demon power products lipo's are well priced and are UK based.. I use 5000mah/25C lipo , and run a 13.5 BL novak and usually use around 2000mah for a 5 minute race in my TC.. and of course you just stick it on charge between heats with no worries..!

I'd recommend a "balance" charger as 7.4v lipo has two cells in it (each with 3.7v that can charge up with unequal voltages and theoretically give less performance...) HOWEVER..! I have 2 lipo's that have lost their balance leads (the 3 thin wires with a small white plug on..) so thought I would have to bin them.. but after talking to the Demon power CEO, I was told they had charged their lipo cells many, many times without "balancing" and without any loss of performance... consequently, I still use those cells and they are still spot-on!!

As for chargers, there are some pretty expensive ones on the market, but lower priced alternatives are available of course.. I have 2 almost identical balance chargers that cost less than £90 inc postage for them both... AND of course, there are usually "used" lipo packs on the 'bay and on RC forums "For Sale" boards... I have two 5000mah lipo packs that came to me 2nd hand for less than £50 for 'em both and which perform magnificently..!

So, come on, jump in with the lipo revolution... I guarantee you won't regret it!!! :D

mad-wolfie
16-10-2009, 12:18 PM
I'd recommend a "balance" charger as 7.4v lipo has two cells in it (each with 3.7v that can charge up with unequal voltages and theoretically give less performance...) HOWEVER..! I have 2 lipo's that have lost their balance leads (the 3 thin wires with a small white plug on..) so thought I would have to bin them.

This is a matter of preference. Personally I think if i went down the LiPo route i'd go for the seperate option... mainly because if one breaks you can replace it so if your balancer goes on the fritz, just chuck it & buy a new one, plus you are not limited should you wish to upgrade your balancer / charger.

As i say the Lipo able chargers are more expensive, but much cheaper than they were.. still not as cheap as chargers that do regular cells. e.g. an X-base charger (that will do everything - but needs a balancer if doing LiPo) costs about £45 - this time last year a similar charger would of cost around £75, but the fact remains i could get a charger that does regular cells for less than half that price such as a pro-peak.

mad dog
16-10-2009, 01:11 PM
Hi Guys,

Looking at getting back into this r/c lark after playing around as a kid etc.

Planning on getting MI3.5 and running it with 10.5 brushless, mainly indoors but will also visit snetterton as this is 15 mins away.

The question is what batteries do i go for and which charger, i am used to 7.2 stick packs and now there is this whole lipo market, before i didnt even know about the whole cycling, equalizing of cells etc.

Been reading many post on here etc and now in a muddle as to what i want / need.

The whole lipo lark, seams to be a much better alternative than cells as they seam less work but would i notice the difference in power output?

And then what size lipo's do i need / go for?

Any help would be much appreciated!!!!!!

Zak,

Go to your local shop for help advice and prices.

IT is not expensive to buy the gear all lipo chargers pretty much come with balancing built in. I just checked prices for you.

Orion Charger is about £59.99
Orion Lipos are about same for 3500 capacity

these are good enough for any standard of racing.

yellowshark454
16-10-2009, 01:42 PM
Zak

There is only one answer, go Lipo.

They are not the domain of the expert, nearly all of our club members now run Lipo. I have run them for 2 years

Lipo technology is not more expensive!!!!

A good set of 6 cells will cost almost as much but last half the time so Lipo batteries are approx 40% cheaper in the long run

And you need more 6 cell packs than Lipos. You cannot do a race meeting on one pack of 6 cells; you need 2 packs minimum but you really need 3 packs.
You can get away with one Lipo but might need 2. If you can (a big if) get by with 2 6-cell packs then you will get by with 1 Lipo

Lipo chargers/balancers may be more expensive but not compared with good 6 cell chargers – its just that you can get really cheap 6-cell chargers. BUT once you add in other equipment like dischargers and coolers the capital cost is higher.

Just make sure you have no issue fitting the Lipo pack under your top deck. I have not looked at this for some time, so it may have changed, but some packs are 23mm high (which seems to be the limit) and can be a problem on some cars and others are 20mm which makes all the difference.

Choose the largest capacity you can afford. If that is 3200 then fine, if it is 5000 then all the better

If you end up with a choice of batteries for the same capacity choose the one with the higher C rating, eg 30c over 25c

If you can afford it, get a charger with an integrated balancer or make sure you can get and fit the manufacturers external balancer at a later stage. You could get a third party balancer but why have the hassle of potential incompatibility or having to change connectors etc etc.

If you are not an “electrician”, take your car down to your LHS, buy everything at the same time and make sure everything comes with connectors fitted and that they all fit together.
There is no need to buy anything which results in you having to cut or splice wires or fit connectors – apart from potentially your battery wires from your ESC
You can also check the battery with your top deck while you are there

HTH

rob_b
18-10-2009, 10:38 AM
are you going to be racing at kellers? if so, come down and give us a look and someone will go through what you need. it can be as expensive or as cheap as you want. you can easily race on 1 lipo there, ive done it many times