alfawaz

Dear all,

I am really stuck! I need your help. I am new to the lipo world as I have always used nitro, but made the decision to go with batteries. I got stuck first as which charger and power supply to buy but then managed. Now after I got the batteries, the balance charger and power supply I am anxious to go ahead and charge the batteries. Why you wonder! I have no idea what the setting I am supposed to enter into the balance charger, and therefore I need your help. Anything would be appreciated.
So
I have two 4s 6500 mAh 70C batteries. I have a turnigy charger capable of 200W in two different ports. And I have a 540W power supply. So when I turned the charger on it asked me for different setting that I was clueless about. I need specific help on how to put the right settings to charger the batteries efficiently and safely.
First there are different modes on the charger:
LiPo charge
LiPo balance
LiPo fast charge
LiPo storage
LiPo discharge
I know the one I am supposed to use is charge since I am trying to charge.
Then it ask for two thing:
number of amps and voltage(1s,2s,3s...)
I know that I have to set the voltage to 14.8V for my battery, but what is the number of amps? is it the amps that I have on my battery which is 6500mAh? = 6.5A?
Do I have to set any of the other settings ?and what should the inputs be?
Please any help would be good! I cannot wait to use the RC car and all is left for me is to know how to charge the battery.

Thank you in advance

chevmaro

iTrader: (25)

Lipo Charge, 4s, 6.5 amps

or

Lipo Balance, 4s, 6.5 amps

Some batteries are rated at a 2c charge rate. That would mean you charge them at 13 amps. It only charges the lipo faster. 1c or in your case 6.5 amps is always safe.

You wont use the other modes. Balance charging balances the cells. It requires the balance cable to be plugged in. Lipo Balance would be the preferred charging mode.

Get a lipo bag and don't charge the battery in the car. Dont leave the battery fully charged sitting around for too long like a month.

Have fun.

mog ruith

iTrader: (6)

To charge lipos you do have to balance them at the same time dont you? Or was i doing it wrong all this time? Im a noob too

stascom

iTrader: (10)

That's what the BAL (Balance) mode does.

akshayp14

i balance charge all the time

Dave H

It's certainly a good idea, especially starting out, as it provides a level of safety in case the cells get out of balance for a variety of reasons.


One clarification, Balance mode does not charge the battery, and should rarely if ever be used. Just use charge with the balance connector attached. Every lipo charger I have will balance charge automatically if the balancer is hooked up while charging.

Use the storage mode if you end up with fully charged or discharged lipos at the end of fun time. Lipos should be stored around half charge, which is what storage does.

Corners

iTrader: (2)

For charge amperage, check the battery to see if a maximum charge is listed. For lipo', it's generally listed as "C", which is equal to the battery's capacity for 1 hour. So, your 6500 man pack, 1C = 6.5 amps, 2C = 13 amps...and so on. A 1C charge is a very safe charge rate for lipo. However, the batteries are capable for much faster, if needed. For example, one of my packs lists 5C maximum charge rate. That's pretty excessive IMO. What you are changing is the charge time. If you have a completely flat battery (which you should NEVER do to a lipo), it will take an hour to charge at 1C, 30 mins at 2C, 20 mins at 3C....etc...

So, use 1C for a safe slow charge. But, note that it's typical for some people to charge between 2-3C. Most people don't really go above 3C. You're not really gaining much time after that point.

alfawaz

Thank you everyone!! This is much help the only two things I am confused about right now is the charging rate and balancing!
I could not find any information of the charge rate on my battery or on the website where I got them. They are SMC batteries any ideas?
And should I just plug in the balancing cable as well while charging? I mean would that help balance the cells although I am using a charging program and balancing?

thank you again

OneHundred%Ng

iTrader: (12)

You should have two wires on your battery. One for charging the smaller one for balancing. Plug them both in. Charge at 1c no more. It is a standard across the board that is used for all batteries. As for balancing, I do it everytime to increase the life of the battery. Some people don't always balance when they charge. It's up to you if you want to or not.

Corners

iTrader: (2)

1C standard charge.
2C-3C fast charge.

See...
http://www.rctech.net/forum/electric...thread-56.html

Darkgenerals

iTrader: (71)

Wait, what?

So your telling me on my charger, a venom Medion, that the balance mode doesn't charge my battery only balances the voltage between the cells?

Excluding that 90% of chargers in balance mode charge at what ever amperage you select and put a small load on a cell that gets higher than the other cells.
Only a few high end chargers actually pump a little extra voltage through the balance port to equalize the lower cells. I will agree this is a superior way of doing it.

Please use balance mode every time to charge your cells, it takes a little bit longer but it helps keep cells equalized.
BTW low end chargers don't automatically discharge a fully charged lipo to put it into storage mode. So if you decide to put a fully charged lipo into storage please discharge before hand.

Dave H

Interesting, based on the manual the Medion appears to be a little different than the various chargers I am familiar with. It doesn't appear to have a balance only mode.

In general there are 3 modes that are overlapping with overlapping terms, can cause confusion:
- Balance charging
- Charging (without balancing)
- Balancing (only, no charging)

Appears we agree that balance charging is the safest method. Especially if one tends to run the packs down a lot, and/or they get damaged with or without it being noticed, and/or the packs are older, etc.

Charging without balancing can be done, but requires (or at least should IMO) more care and knowledge of the packs condition. Risk is if something does happen to the pack and it's not caught, as balance charging should, a quite nasty fire can easily occur. A risk not worth it for me to save attaching a connector.

Balancing only, without charging, does balance/equalize the voltage of the cells just as you mention, but is almost always a waste of time and can even be harmful to a degree. I think it's smart that the Medion apparently has left this capability out.


Good point, some chargers don't have the intelligence to automatically detect charge or discharge for storage. In those cases I would see if the discharge voltage can be increased and just discharge, targeting an end voltage of around 3.75 to 3.85V per cell. Little need to discharge and then charge to storage if it can be avoided, why add wear to the lipo.

Dave H

At the risk of going off subject a bit, just want to avoid any possible confusion. 1C charge rate is fine for typical RC lipo batteries, but not all batteries. For example don't try charging a gel cell starter or field box battery, or an automotive lead acid battery, at 1C. Many other battery types are also charged at different rates than 1C.

jwmustang

iTrader: (11)

Just a note. If you select Balance Charge & you dont have both sets of wires connected the charger will error out to let you know you have a wire disconnected or you have a bad cell.
Its pretty fool proof. The chargers are pretty safe so dont worry too much.
Also when you balance charge you can also see each cell as its charging. Just read your manual it will show how to get to that menu.
Make sure you unplug the battery from the car when you are done. If you dont the ESC will discharge your battery & kill it.
If you dont have a lipo bag you should charge it on a piece of tile or metal plate.

Dave H

No one has mentioned fast charge, it can be very useful. Towards the end of a lipo charge the charger slows way down, fast charge stops the charger sooner. Does reduce the charge a bit, but saves a lot of time. Very useful for playing/bashing or racing modified classes. Easier on the lipo too.

Not for racing stock classes where you want every bit possible in the battery.

It's nearly the only way I have charged for the last few years. Still with the balancer wires connected.