my charging against Vikk'si charging wiki

[Keratos]

This is a really useful blog:
http://www.rcheliaddict.co.uk/blogs/...-chargers.html

Just wondering whether you would agree or not with my calculations for my setup:

My LiPo is a 2s 7.4V 1500mAh.

volts * amps = watts , so 7.4*1.5 = 11.1W

so a typical 50W charger will charge my batteries at 6.7A (50W / 7.4V). this is well within the 1.5A rating of the battery so does this mean the battery will charge quicker? could I get a reduced wattage charger?

thanks in advance.

[Delarado]

Yes the battery will charge quicker at that rate.

Lipos as a general rule of thumb should be charged at 1c. This means for example a 1500 mah battery should be charged at 1.5a. A 5000mah battery at 5a, and so on. A 1c charge will take one hour from a completely dead state (Which A lipo will never be)

A 2c charge will take half an hour from a completely dead state. 3a for a 1500mah battery. 10a for a 5000mah. A 6.7A charge on a 1500mah battery will take about 15 minutes or less, but is quite a high rate to charge a battery at. Generally it is believed that for longevity, charging at 1c is the best. The faster you charge lipos the less cycles you will get out of them before they start to deteriorate and not perform their best. (you may get 400 cycles if only ever charged at 1c or 300 if charged at 2c, or 50 - there is no concrete research on this)

However, just be aware that if you ever fancy electric heli's its worth getting a decent charger.

I started out with an 80w charger and quickly found that it couldnt even charge the battery for my electric 500 at 1c, which meant that if I ever wanted to go flying with all four of my packs it would take over 5 hours to charge them all.

I then invested a couple of hundred quid in a decent charger, it does 1000w. I can now charge 6x 5000mah 6s batteries at 1c all at the same time, putting 30a into the batterys and charging in paralell.

If you ever think youll go electric its worth considering. For Nitro though any charger should work, the flight batterys that run the servos are very small in comparison to others.

Just FYI most packs will list their max charge rates on them, and they do differ. I use the hyperion G3 series of Lipos on my heli's, and they state a max 5c charge, which means I can charge my 2000mah pack at 10a, meaning it can be charged in about 10 minutes usually, which is really handy.

For unknown brand and age batterys though (Such as you have) I'd stick to 1c charges for a bit. 2c max.

Your maths is correct by the way.

[Delarado]

this is a good read https://sites.google.com/site/tjingu...e-for-charging

[royotr]

my charging against Vikk'si charging wiki

This will do the job :- Http://www.heliguy.com/Extras/LiPo-C...lance-Charger/

EK2 0855 11.1v Balance Charger is a simple lipo charger that will do the job you require and very little else. Small enough to slip in your pocket .

[Keratos]

Ok, good tips. Thanks buddy. I will stick to 1C.

Not sure if I will go electric, they certainly seem to be increasingly popular though. The reason I chose Nitro is because as a beginner , when my flight time is up I just refuel and go. With electric it was a case of acquiring say 5 packs plus a good (very good) charger such as yours, which all increased the initial capital outlay.

thanks

Yes the battery will charge quicker at that rate.

Lipos as a general rule of thumb should be charged at 1c. This means for example a 1500 mah battery should be charged at 1.5a. A 5000mah battery at 5a, and so on. A 1c charge will take one hour from a completely dead state (Which A lipo will never be)

A 2c charge will take half an hour from a completely dead state. 3a for a 1500mah battery. 10a for a 5000mah. A 6.7A charge on a 1500mah battery will take about 15 minutes or less, but is quite a high rate to charge a battery at. Generally it is believed that for longevity, charging at 1c is the best. The faster you charge lipos the less cycles you will get out of them before they start to deteriorate and not perform their best. (you may get 400 cycles if only ever charged at 1c or 300 if charged at 2c, or 50 - there is no concrete research on this)

However, just be aware that if you ever fancy electric heli's its worth getting a decent charger.

I started out with an 80w charger and quickly found that it couldnt even charge the battery for my electric 500 at 1c, which meant that if I ever wanted to go flying with all four of my packs it would take over 5 hours to charge them all.

I then invested a couple of hundred quid in a decent charger, it does 1000w. I can now charge 6x 5000mah 6s batteries at 1c all at the same time, putting 30a into the batterys and charging in paralell.

If you ever think youll go electric its worth considering. For Nitro though any charger should work, the flight batterys that run the servos are very small in comparison to others.

Just FYI most packs will list their max charge rates on them, and they do differ. I use the hyperion G3 series of Lipos on my heli's, and they state a max 5c charge, which means I can charge my 2000mah pack at 10a, meaning it can be charged in about 10 minutes usually, which is really handy.

For unknown brand and age batterys though (Such as you have) I'd stick to 1c charges for a bit. 2c max.

Your maths is correct by the way.

[Keratos]

that will do for now. should keep me good for a year or two whilst I train.
Thanks

This will do the job :- Http://www.heliguy.com/Extras/LiPo-C...lance-Charger/

EK2 0855 11.1v Balance Charger is a simple lipo charger that will do the job you require and very little else. Small enough to slip in your pocket .

[dogbiscuit]

This will do the job :- Http://www.heliguy.com/Extras/LiPo-C...lance-Charger/

EK2 0855 11.1v Balance Charger is a simple lipo charger that will do the job you require and very little else. Small enough to slip in your pocket .

this apears to be a 3cell charger and not for 2 cell nitro electrics lipos

[cjcj1949]

When looking at the charge rate you need to now that lipos vary from 3V when too flat to 4.2V when full. They should usually be kept from above 3.8V and certainly no lower than 3.7V. The depth of discharge is a real killer and if you discharge to 3V or lower your lipos will soon die. This is well known. Most 50 Watt chargers will only charge at 5amps and all chargers have restrictions or small print on what they will do. They will usually only give maximum output at a certain voltage. The ichargers are very good. You usually want to charge a lot of batteries and extra chargers are very useful. Bear in mind that a 2C charge will only be twice as fast as a 1C charge during the first phase of charging until the cell volts reach 4.2V. Then the charge current is reduced until it reaches about 10% of the max charge you've selected. You don't have to keep charging, you can stop at any time and stopping early will give you slightly shorter flights but your lipos will last longerr.

[Vikki]

For a two cell you'd be better chucking 9V into that formula. The batteries charge at a higher voltage than the voltage printed on the battery.

Chris said it, think 4.2V per cell. That is 8.4V for 2s but round up to 9V.

It's a good idea not to run these chargers close to their limit. Non-fan cooled get very hot and that shortens their life span. The hotter they get the shorter they live (chargers that is). My B6AC has inside it a modified laptop charger!!!! No wonder it got hot at full belt!

[Keratos]

Understood Vikki. Many thanks for the advice. I will do some googling. I feel the 50W is a tad overkill for me, but with 9V into the formula (resultant is 13.5W) I can look for something around 20W.
many thanks and that was a great blog entry you created.

For a two cell you'd be better chucking 9V into that formula. The batteries charge at a higher voltage than the voltage printed on the battery.

Chris said it, think 4.2V per cell. That is 8.4V for 2s but round up to 9V.

It's a good idea not to run these chargers close to their limit. Non-fan cooled get very hot and that shortens their life span. The hotter they get the shorter they live (chargers that is). My B6AC has inside it a modified laptop charger!!!! No wonder it got hot at full belt!

[Vikki]

An 80W charger B6AC type is about the £45 mark. It will cover you for 3s batteries if you decide to go quad or 450 route. Even the 50W if it's cheaper. Don't paint yourself into a corner or you'll be buying oh, your nitro aren't you, I'll shut up now. Rx battery, mumble-mumble.

[royotr]

my charging against Vikk'si charging wiki

this apears to be a 3cell charger and not for 2 cell nitro electrics lipos

Yes that's correct sorry about that, even though some retailers list it as 2s 3s charger , 99% certain it's only 3s. The previous eSky EK2-0851 infact did both although at a slightly lower current. .

Keratos, I'm sorry about that , I know that you want to keep things simple and cheap. There are other, available at most model shops at a similar price that are pretty basic in their functions such as the JP basic charger used by many of use:-

http://www.brentfordrc.co.uk/scripts...idproduct=1035

I know that you don't want an expensive multicharger, as in earlier threads of yours , others and myself have listed the benefits , versatilities and long term economic sense of buying a good , and high capacity charger. Of course the sense of such a purchase is only IF you decide to stay in the hobby. Many that start of with the larger nitro powered helis end up giving up because a screaming 50 glow billowing plumes of smoke is too much before its even lifted of the ground, others have a couple of forays and then a crash. As a minor crash with a 600 is at least £100, many give up then with their bank balance still in the black. £50 charger would hen be a waste never mind a £200 one.

[Vikki]

Does that require an external power supply? The little baby I suggested is mains powered (and site battery, too).

Mind you, a little tiddler of a supply wouldn't come to much. Is there mains powered chargers with lower capacity available for Keratos? Keratos, have you got an eye on a 50W one? Don't Eflite do one? I'm sure I have a power brick with one of the chargers I got from a heli box from them. Memory fails me know, typical.

[Keratos]

I dont know ??
Dont have my eye on anything now, have to admit to being confused. I'm minded to conclude that a 20W 2S charger will be fine. For now. For about a year or two. I mean its like £20-30, so if I need something different in a couple of years then so be it, I've spent £1 a month on a charger.
I'm nitro for a couple of years me thinks.

This "little baby" you refer to Vikki, is there a link you have?

Thanks


Darren

Does that require an external power supply? The little baby I suggested is mains powered (and site battery, too).

Mind you, a little tiddler of a supply wouldn't come to much. Is there mains powered chargers with lower capacity available for Keratos? Keratos, have you got an eye on a 50W one? Don't Eflite do one? I'm sure I have a power brick with one of the chargers I got from a heli box from them. Memory fails me know, typical.

[Keratos]

Thanks pal. no need to be apologetic. I am not sensitive. Quite a rugged Lancashire old fogey actually. No probs mate.
I think i will go for cheap and cheerful, in keeping with the capital outlay so far. i dont want to go head over heels in case I dive out of this hobby.
Many thanks for the link.

Darren

Yes that's correct sorry about that, even though some retailers list it as 2s 3s charger , 99% certain it's only 3s. The previous eSky EK2-0851 infact did both although at a slightly lower current. .

Keratos, I'm sorry about that , I know that you want to keep things simple and cheap. There are other, available at most model shops at a similar price that are pretty basic in their functions such as the JP basic charger used by many of use:-

Lowest prices for LI-POLY 1-3 CELL 250ma-2AMP CHARGER (12V) : Brentford Radio Control Centre

I know that you don't want an expensive multicharger, as in earlier threads of yours , others and myself have listed the benefits , versatilities and long term economic sense of buying a good , and high capacity charger. Of course the sense of such a purchase is only IF you decide to stay in the hobby. Many that start of with the larger nitro powered helis end up giving up because a screaming 50 glow billowing plumes of smoke is too much before its even lifted of the ground, others have a couple of forays and then a crash. As a minor crash with a 600 is at least £100, many give up then with their bank balance still in the black. £50 charger would hen be a waste never mind a £200 one.