New to Lipos.

There seems to be alot of numbers surrounding these packs. What do they mean. I'm somewhat lost.

I'm looking to use a 35c 5000 pack, as that is what was recommended to me. What does the 35c stand for? I'm sure 5000 is milliamps... but which number does what?

Also, looking for a charger that will carry these type packs. I've been looking at the Team Orion Clubman Advantage Lipo Edition charger. It's in my price range, but I don't want something that won't do a sufficient job.

Thanks for any help!

There should be a sticky on this type of stuff...

"mAh" - The pretty big number 3000, 4200, 5000, etc is the packs milliamps
Or how much it can hold. It is a factor of load over time

"C" - Is a number between 10 & 50 or even 60. It is the multiplier of the mAh ratting for instantaneous current or punch.
3000mAh x 30c = 90amps
4000mAh x 25c = 100amps
5000mAh x 20c = 100amps
5000mAh x 40c = 200amps

"S" - Is the number of cells in a pack 1s = 3.7volts, 2s = 7.4v etc
The maximum voltage that cells are at when fully charged is 4.2v/cell
Packs should be stored at 3.6-3.8volts per cell.
Balancing is also a concern in my opinion.
If you have an old out of balance pack & it is charged to 8.4v (peak 2s), & one cell is low, that means the other is likely high.
Over charging & over discharging makes the cells unstable & they can/will catch fire.

The benefits of a fancy charger is usually more possible current & voltage output & comfort features.
I have inexpensive $60 chargers, & $125 chargers... I use both types.

This is the basics, & there is a lot of little things to consider when choosing a pack.
Weight, size, etc...

Likpo deals with 3 diff voltages - the cell minimum voltage, a nominal voltage and the cell maximum voltage. Lipos cells are all alike in this regard. If you overdischarge a cell below ~3volts (cell minimuim), you can damage the cell (it will swell or puff). Likewise, if your overcharge a cell above the cell maximum of 4.2v, it can swell and or vent, again damaging the cell. The nominal cell voltage of 3.7v is basically used for comparison - usually when lipo voltage is mentioned, its on the basis of the nominal voltage.

Lipo batteries are assembled using multiple cells wired in series. Wiring in series makes the voltage add, so two cells wired in series (2S, the 2 is the number of cells is series) would be 3.7v + 3.7v = 7.4v nominal. This 2S lipo coming off the charger fully charged would read 2 x 4.2v = 8.4v and should not be discharged below 2 x 3v =~6v. I use approximate cause some lipo cells are more sensitive to low voltage than others. I personally use 3.2v/cell as my cutoff.

A lipo capable charger prevents overcharging - its built in to stop at 4.2v/cell as soon as you tell charge you're charging a lipo. The low voltage protection is provided usually by your esc - most modern opnes have some kind of low voltage cutoff (LVC) builtin. Some ar eprogrammable as to voltage ans some are programmed for specific voltages already. There are also add-on type devices for escs that do not have an lvc.

Run time is dependent on battery capacity - mah (milliamp-hours) of the battery. This is like a gas tank. Bigger number, longer it will run. The "C" is the lipo discharge rating - what amperage the lipo can produce. Its simply calculated from mah and C rating as capacity(mah)/1000 x C = amps discharged. So for the 5000mah 35C pack you mentioned, it can discharge 35 x 5000/1000 = 175amps. This provides a basis to compare lipo capabilities from brand to brand and influences price as well.

There are a lot of chargers out there, are you looking for an AC/DC charger?

Ac/dc would be nice, bt not totally necessary. Just looking for the best for the budget. The one mentioned above has good reviews, but just want something that will carry what I need it to carry.

Thanks for all the information so far!

If you're going to be using 2S, a good 50watt charger will work fine and they are available from less than $50 to $110. If you're going to charge 3S and 4S, you'll need charger with more output power, otherwise the charger will limit charge current to stay under its power limit and that will make charging take longer. 100watts will let you charge about 6000mah 4S without running into any kind of limiting. Theres a good AC/DC charge in 100watts, but there seems to be a gap with DC chargers - there are a few 50watt chargers and then they jump to a few hundred watts with almost nothing inbetween.

Its also worth while to but a little more than you need currently so you have some room to "grow". That may help avoid having to buy another charger later. Def a big beilever in using a balancing charger, I use 4 different ones myself.

Recomendations?

Looking to spend less than $100, preferably less than $75.

That budget pretty much leaves only the chargers that HobbyPartz sells, the Thunder AC-6 and the SkyCharger. They are 50watts balancing chargers. The Skycharger has a few more options, but haven't heard any one actually using the USB options.

http://www.hobbypartz.com/lifechargers.html

i have the orion clubman lipo edition charger..works great..never had no problems with it.

turigy is a real good charger as well.for the cheap price ya cant beat it at all.
i have 2 of these.

Okay, so give me a comparison between a 35c 5000 and a 28c 5300.

Discharge capability comparison ??

35c 5000mah - 175amps, 28c 5300mah - 148.4amps

I dont mean to interup the thread but I hated to start a new lipo thread myself. Seems like this one has good info in it so I will go with my ? in this one. Ok so I am totally lipo illiterate. I am looking at getting into 2wd buggy 13.5T brushless. What battery do I need? I was looking at stormer and their homepage shows some 1s batterys. I was thinking that you need 2s. Would the 1s be good or do I need a 2s? I have a guy I am getting two 2s used packs from at a decent price but I thought I would maybe pick up atleast 1 new pack for the main.

2s and atleasr 4200 mah. I run thunder power 5200 50c lipos

Hi all! I'm very new round here so please be gentle! I also have a question regarding Lipo technology, and specifically my charger...

I'm starting using Lipo batteries now, for my rock crawler and my helicopter. I would also like to use Lipo batteries in my sons Losi DT sometime in the future..

My question concerns my charger:

I recieved my new charger yesterday, its a Dynamite Passport Ultra, capable of balance charging Lipo's and also charging/discharging Nicad and Nimh batteries. (I've decided I need to take much better care of ALL my batteries!)

One of the settings is called the "Capacity cut off". Obviously I've set this (for now) to be the same as the capacity of the battery I'm charging, whether its a 2200mAh Lipo, or a 1600mAh Nimh reciever pack etc...

My old Fusion charger never had this "Capacity cut off" setting before? I thought the charger would automatically detect the pack becoming charged, peak, and then shut down/go into trickle mode.

Any ideas on why this setting is there, do all Lipo chargers have it? The setting is also applicable for Nicad/Nimh charging.

Another quick question: I charged my 1st Lipo pack last night. I can honestly say I don't think I've been as paranoid before in my life! I think it was all the scary videos on YouTube of people doing franky VERY stupid things with these batteries...

Anyway, I set the voltage/series cell count(3S), the charge current (I charged a 2200mAh pack at 2 amps), and the capacity cut off (2200mAh). It took about 1.5 hrs to charge the pack, and it was very interesting to watch the charger balancing the cells. When the voltage in the cells reached 4.2v it shut down automatically.
The battery didnt get warm at all. Is this normal? I thought a little bit of heat may get generated by the charging process. But this is the 1st Lipo battery I've ever charged, so I'm not sure....?

Any ideas good people?
Steve.

That is basically a safety setting - some chargers use a 'safety time' to terminate charge if the normal charge termination doesn't happen for one reason or another. The capacity setting is also used to terminate charging as a safety feature. This is typically more of a prob for NiMh where sometimes a peak is not detected and the batt just keep charging and charging and getting hotter and hotter til it vents.

Some lipo cells are underrated - I've seen 5000mah labeled lipos charge to 5500-5600mah - you want the extra if its available. I would set the capacity to 10-15% over the capacities that you're charging so if yours are underrated, you'll get the benefit of any extra capacity. For NiMh, you're correct - set at rated batt capacity.

If lipo does not terminate normally on voltage, charging should be stopped. But if they voltage is still below 4.2v/cell and capacity hits 5000mah, you're not hurting anything to let charging continue.

You're not supposed to leave charging batts unattended. At the minimum, you shoud be there often enough to be aware of when batt is getting close to full and stick around to make sure batt terminates properly.

Lipo should not get warm - lipo has such a low internal resistance, thery is just no heat generated in charging. Don't get lipo confused with NiMh where the chemical reaction taking place is exothermic and the much higher internal resistance leads to peak temps of about 130F. You should not see anything like than from lipo.

Thanks for the great advice there! You certainly seem to know your stuff Mr 360!

I shall try nudging the capacity setting up a little (Lipo only) to see if I can wring a little extra capacity out of the packs. The Passport Ultra also does have a 'max charge time' setting...

I kept a constant eye on the pack whilst charging. Those scary Youtube videos haven't helped at all! (was cool watching it balance the cells) So I actually thought I mustn't be charging them properly when NO heat was generated at all.

I've normally had nitro engined monster trucks for last 6 or 7 years, so all I had to deal with was an FM tranny's batteries and the reciever packs in nitro engined models. This electric stuff is all pretty new to me!
Now I have a rock crawler running a tiny Lipo battery, not to mention some Lipos in my Blade 400. Its been a steep learning curve.

I thank you again, for your advice.
Steve.