Lipo Battery Charge rates?

[OldSchoolRunner]

Well I have finally entered the world of Lipo. I have bought myself a small Prophet hobby charger from my local shop. I have a 2 cell Lipo battery that says that it is a 2500mah. Now the charger has different charging rates 0.5A, 1A, and 2A what charging rate can I charge this battery at? The instructions say that for every 1000mah I can charge at 1A does that mean that I can charge this battery at 2A because it is a @2500?

Thanks

OSR

[TA-Mark]

A 1C charge for a 2500mAh Li-Po is 2.5 Amps. 2.0 Amps on your charger is the closest to the recommended charge rate.

Does the charger have a balance function? A fully charged pack at 8.4 volts can have one cell at 4.3 volts and the other at 4.1 volts if the charger only charges at a total voltage for the pack. The cell that is overcharged (4.3 volts or more) will not last long and puff up. And in the same way, when you hit the total voltage 6.0 volt cut-off in the ESC, that cell that started at 4.3 volt is now 3.1 volt and the cell that started at 4.1 volt is now 2.9 volt and in an under voltage situation. The 2.9 volt undercharged cell will also fail in much the same way as an overcharged cell. Hence the importance of a balanced Li-Po charger that ensures both cells are at 4.2 volt each at full charge.

[OldSchoolRunner]

I don't think it does a have a balance function. It was only $40 at the local hobby shop and I wanted to make sure that I liked the Lipo thing before I jumped in head first. So what you are saying is that I can charge the 2500mah battery at 2A? Is that right?

OSR

[TA-Mark]

You can charge it at any rate that charger will run at. All are less than the recommended maximum. 2.0 Amp is your best option (about 1hr 15min charge time from 6.0 volts to 8.4 volts). At 1.0 Amp is will take about 2hr 30min and at 0.5 Amp about 5 hours.

Shame on the LHS for selling you a non-balancing Li-Po charger. $20-$30 for a Imax B6AC balancing charger on evilbay.

[OldSchoolRunner]

Ok this is some good info Mark! Now what does that mean if I get a 5000 mah battery or a 8000mah battery? Can I still use this charger? Probably when I get to that point I will need to get a better cahrger with the balance function I know that, but does this mean that this charger is now useless for higher mah batteries?

OSR

[TA-Mark]

It'll still charge them, though it will take ages (4 hours @ 2.0 Amp for the 8000mAh), and you risk ruining more expensive packs with a charger that doesn't balance.

[OldSchoolRunner]

Mark I totally thank you for all the help! I did look up that charger that you recommended on ebay. It looks pretty good and definately has more functions that the one that I bought at the local hobby shop. Is this the charger that you use? I think that I should have done a little more research into the chargers before I bought one. I guess I could always return it and tell them that they didn't really tell me about balance functions and such... Will the Imax B6AC charge my batteries faster?

OSR

[GregM]

I agree that a balance port is a must for LiPo capable chargers.

The cheaper Imax B6 chargers on ebay are supposed to be knock-offs, aren't they?

[richard.tufty]

I bought one of these on sale just before Xmas for less than $40:

http://www.hobbypart...ac6smbachw.html

it seems to work just as well as my Hyperion, plus it has a Lipo storage mode on it which the Hyperion doesn't.

There are a few videos around showing the differences between the genuine B6 and knock offs, given the price difference ($12) is not that great, if you go for a B6, get a real one:

http://www.hobbyking.com/hobbyking/store/__6478__IMAX_B6_AC_Charger_Discharger_1_6_Cells_GENUINE_.html

or a fake:

http://www.hobbyking.com/hobbyking/store/__15437__B6_AC_Plus_Charger_Discharger_1_6_Cells_Dual_Power_COPY_.html

The DC only ones are even cheaper if you have a power supply already.

[alfagta]

OSR , please do return the charger you bought , tell the guys at the LHS that it is essential for your's and your families safety that you have a balance charger , the imax b6 is the most copied charger out there and so i will suggest that you are very cautious with purchasing one, the real ones are great , some of the copies are great but some are plain dangerous , its impossible to spot the difference from the outside , perhaps one of the guys on TC forums that have one could point you in the direction of where they got theirs so you know its a goody .

[94eg!]

Having personally used the Tunder AC6 & the Genuine IMAX B6AC side by side, I can say my older Thunder is the better of the two. It will spend a lot more time balancing unbalanced cells than the IMAX charger. I have even put packs on the Thunder AFTER balancing on the IMAX, and they will continue to even out for 20 minutes on the Thunder (voltages verified with a separate volt meter). The IMAX seems to give up balancing rather quickly, leaving the cells as much as 0.03 volts off from one another (4.17 & 4.20). The Thunder will balance until the they are perfectly even at rest, though one cell may drop by 0.01 shortly after the system finally cuts off. I think the Tunder added an extra 100+ mah to the low cell. This is my experience with the cheaper Turnigy Lipos and a several older Tenergy/Intellect packs.

[berman]

Agree with alfagta, take it back and get a better charger with balancing capabilities. The only way I would use a charger without a balance function is if I was charging a 1 cell lipo, and thats because you dont need it.

Here all those horror stories about lipos? Dont become a victim of one because of neglegence.

[alfagta]

you could also take a look at the eXtreme 605 , it does require a 12v supply but they are cheap and readily available , i have been using one for many years and it has always been perfect, if the cells are in good shape it balance charges rapidly , if they are not such great cells it takes as long as is needed to balance charge them , it has been the best charger i have ever owned and for the cost is well worth a look,

the turnigy accucel (also requires a 12v supply) is really well regarded too ,

dont be put off by the separate power supply as it allows you to use the charger in your car should you wish to take a drive to a nice spot for a prolonged rc session and reduces the cost should you ever have a failure of the charger or power supply.

the thunder ac6 does look like good value too , but, personally i still have a dislike of any integrated charger /power supply having had 2 fail me in the past.

have fun shopping and even more fun with LiPo

[OldSchoolRunner]

Does the Imax B6AC have the storable mode too? Hmmmm? Any reputable sellers on ebay that are actually selling the Imax B6AC that are not knockoffs? Will the Imax B6AC charge my battries fast or will it be the same speed/

Thanks

OSR

[94eg!]

Yes the B6AC has storage mode, but again, it sucks at balancing. The AC6 is better.

[Psylence]

I've got a duratrax onyx 245... can charge and balance 2 batteries at a time of pretty much any type. It was only $100 or so, and has really taken the pain out of learning about charging.

[richard.tufty]

dont be put off by the separate power supply as it allows you to use the charger in your car should you wish to take a drive to a nice spot for a prolonged rc session and reduces the cost should you ever have a failure of the charger or power supply.

the thunder ac6 does look like good value too , but, personally i still have a dislike of any integrated charger /power supply having had 2 fail me in the past.

Both my chargers are AC/DC, having the integrated power supply doesn't preclude you from using it at the nice driving spot. You could always use an external power supply if the integrated one gave up too. The main reasons I went for AC/DC chargers was the cost of a good power supply plus a case for it to avoid exposed wires added to the DC only supply cost was more expensive than the AC/DC one, plus it's all a bit neater.

Still, that's just my preference, I know lots of people like the DC only ones too!

Oh, I found out recently that the later versions of my Hyperion (EOS0606i) do have a Lipo storage mode, mine is an early one that does not though. Still, they are much pricier than the Thunders and IMAX chargers we are talking about, and owning both, I would not hesitate to buy the cheaper ones again if necessary. Nothing wrong with the Hyperion, but it's not worth 3x the cost of a Thunder, imho.

[PaPeRo]

http://www.hobbypartz.com/75p-1220-charger.html

[berman]

Nothing wrong with the Hyperion...

I have the same Hyperion, (but with the storage mode) and its a big steaming pile of dog doody.

1, for a 'quality rc product' as blown on about on the front, it has cheap nasty wire for the balance adapter harness.

These over a short period of time break easily, usually at the ends inside the plugs, had they spent a buck more and fitted them with silicon wire like cheaper companies like Turnigy etc we wouldn't have this problem. Hyperion do the same on their batteries, it gets annoying every second week taking the lid of the top of a classic pack lipo to cut the cellophane and solder the broken wires back on.

2, the battery lead is live. Even when no charge is actuated and the charger is hooked up to your car battery the positive and negative have current. I have never had another charger that is live without it actually being set to charge. This is very dangerous. If you have a stainless workbench, or are charging under the bonnet of your car, you have to be super cautious about having that hooked up to your car and swapping batteries. By all means all wire should be treated as live, but when other charger manufacturers can make them without the danger, you would thing an expensive brand like Hyperion could too. I had my old one on my plastic airbox, went to grab another battery, and the lead slid down the engine bay and touched my a/c piping.

3, no preset battery storage option. You have to set up each and every battery every single time if it wasnt the same as the last o e charged. Really annoying if you are taking a multitude of packs for different cars.

Sorry, I wouldnt recommend Hyperion products to anyone.

[speedy_w_beans]

Maybe it's time for a sticky FAQ on LiPos and brushless systems in the electrical part of this forum...

[bromvw]

ebay sellers uetuk sell the genuine IMax B6 charger . They are in Oxford and warranty every charger they sell . I totally agree that there are many knock off's of this charger but if you buy a genuine one with the SKYRC Hologram and scratch off security code its a decent quality charger for the money if not high end equipment . You have the piece of mind of now being able to check the security code online to ensure its not a cheap copy with the genuine artical BTW . If you do come across any of these without the new hologram sticker and the scratch off code AVOID .

[shenlonco]

The duratrax onyx lipo chargers work good you can get one cheap in tower hobbies scratch and dent section everything I got from them in scratch and dent almost always looked new.

[OldSchoolRunner]

Some really good info here! I will look into the charger from the Oxford area bromvw! Do you have a link to this actual charger mate? I am still wondering too if the better the charger will it charge the batteries faster??

OSR

[TA-Mark]

I think this is the one: eBay This is the dual power supply one (AC/DC). He's also got this one: eBay which has an external power supply to run from mains power.

[bromvw]

I think this is the one: eBay This is the dual power supply one (AC/DC). He's also got this one: eBay which has an external power supply to run from mains power.

Thats the place Mark . Thanks for posting the links . These are Genuine items and a reputable seller .