Stupid question...

On average, how long should it take to charge a 4s 6500mah lipo with a charger capable of 7A at a 1C charge rate from LVC(3.4v)

I have a charger now that can only charge up to 6A and it takes forever to charge the above pack. About 90 minutes. And for whatever reason, it only charges at 3.85A max lol.

I'm trying to justify the extra cost of upgrading to a charger capable of 7A or higher.

Thanks!

It's all about the power wattage capability of the charger. It would charge a 1S or a 2S battery at 6 amps no problem, but a 4S battery it wouldn't be able to, no way. Even a charger with a max output of 7 amps wouldn't have enough power. Somebody a lot smarter than me can probably answer the question better.

You only have a 60 watt charger.
How much power do you need? Amps x Volts = Watts
Want to charge a 4S pack (16.8 Volts max) at 7 Amps max? Need a charger with at least 118 watts.
7A x 16.8V = 118 Watts

I'm no math wiz, and some people will use battery nominal voltage for figuring wattage.
2C charge rate for your 4S 6500mAh pack? You would need a charger with at least 218 watts.
13Amps x 16.8Volts = 218.4 Watts

HERE....Understanding wattage in relationship to charging - TJinTech

Thanks for this. New to electric, been a nitro guy my whole life.

Only plan on charging at 1C for pack longevity lol.

Off to find a new charger :-(

Thanks guys!

As calculated for you you need 120 watt for 1C, be wise and go for something that can do at least twice the needed rate so you can do a faster charge and also a 1C charge with future higher capacity batteries.

In Layman's terms, a 1C charge rate will take approximately 1 hour to charge a battery.

Convert the mAh (milliamp hour) capacity number to an Ah (Amp hour) number...Just take the capacity of the pack in mAh, divide it by 1000 to get Ah, or just move the decimal point left three times. Your 6500mAh battery pack = 6.5Ah battery pack will (theoretically) discharge 6.5 amps in 1 hour, and will take 1 hour to charge at 6.5 amps. 1C charge rate = 1 hour . Approximately because of variables. To cut the charging time in half of a 1C charge rate, you would do a 2C charge rate. Charging your 6500mAh (6.5Ah) at a 2C rate...you would set your charger to 13 amps (6.5 x 2), and would take approximately 30 minutes to charge. This is assuming you have a charger with that much power.

Lot of good info here...http://www.rogershobbycenter.com/lipoguide/

For sure!

Looking at a iCharger 406DUO

There goes the wallet!

Thank you for the explanation. I understand that much. Most likely will keep it at 1C but if at the track I'll bump it up to 1.5C to shorten charge time.

If you want to get a AC charger this is a nice option.

https://www.amainhobbies.com/protek-...k-8519/p578442

opps might be off on post above with mistaken info given,.its 3 placest left you dont want a guy trying to charge at 65 amps do you.. 6.5amps..on a 6500 mah battery.ohms law learn it and use it its a great point of knowledge.https://www.electronics-tutorials.ws...its/dcp_2.html

Good catch. Thanks.

np.. math is my 2nd fav thing no biggy ..

Was thinking of this one also. Not sure if I want to spend almost $400 on a new charger/power supply.

If you are going to race, chances are you will never have to recharge a battery from zero so your charge times will be a lot less.

Example... I use 2s 8000ma batteries in my SCT... 10 min race I still have approx 25% of the battery left.
I use a Protek charger that is 80w and I charge at 8a. It takes about 30 minutes to charge back to full capacity.

LVC is set at 3.2
Note that I never run my batteries down to low volt cut-off... I use a timer set to 8 minutes when practicing.