I have two batteries for my blx 4x4 Kraton 4s, a 3s and 4s battery. The 4s says us 2c charge rate, and the 3s is 3c. The charger says 1-4a charge rates but no c rates. I've been using 3a for the 3s and 2a for the 4s. Is this safe?
Charge rate questions.
- Thread starter CameronCodes
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Knxwledge
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The charge rate depends on how much capacity your battery have. For example, if its a 5000mah - charge it at 5a which is 1C. 4000mah = 4a and so on.
Its best to charge batteries at 1C for longevity.
Its best to charge batteries at 1C for longevity.
You have to calculate the Amps yourself. It makes no difference how many cells (3s vs 4s) the battery has.
1C charge rate means charging at 1 Amp for every Ampere-hour of capacity.
Lets say you have a 5.000 mAh battery and we want to charge it at 2C. We multiply the 5 Ampere hours with the 2C. We get 5x2=10. So 10 Amps is the correct charge rate for charging at 2C.
We can tell you the correct rate for your batteries if you tell us about their capacities
- Thread starter
- #4
So I've been doing this charging incorrectly for about a year now and the batteriesare still working, should I get new batteries, or should 8 be OK if I charge at 1c from now on?
Yea, the C-rate is tied to the capacity -mah- but you want to use Amp Hours (ah), instead of mili-amp-hours)mah. So 5000mah becomes 5ah.
1c = capacity in amp hours. So 1c on a 5ah battery is 5a. 2c is 10a, etc.
BUT - for charging, you also need to look at watts - mostly, the total output watts of your charger. if we skip the math for now, As a rule of thumb for 5000mah packs, you need 25w PER CELL that is being charged. That is, to charge one cell at 5a needs 25w of charger power. So you 2s needs 50w, your 3s needs 75w, and the 4w needs 100w.
1c = capacity in amp hours. So 1c on a 5ah battery is 5a. 2c is 10a, etc.
BUT - for charging, you also need to look at watts - mostly, the total output watts of your charger. if we skip the math for now, As a rule of thumb for 5000mah packs, you need 25w PER CELL that is being charged. That is, to charge one cell at 5a needs 25w of charger power. So you 2s needs 50w, your 3s needs 75w, and the 4w needs 100w.
Depends on the capacity of your Lipos. You chose a low current, so you probably charged with even less than 1C. Everything should be fine.
Depending on the battery size, they should be fine. charging at less then 1c will not hurt the lipo.
- Thread starter
- #8
The 3s is 5000mah and the 4s is 52000mah
What is the make/model of your charger? What is the Mah of your batteries?
Edit - so 5a would work for a 1c charge rate for both of those (close enough for the 5200).
Edit - so 5a would work for a 1c charge rate for both of those (close enough for the 5200).
Knxwledge
Active Member
Charge the 3s at 5a and the 4s at 5.2a
I am going to do out on a limb here and say this is probably a budget 30w-50w charger. If this is correct, you will never hit 4a with the 4s pack - as the charger just can't put the wattage...
- Thread starter
- #12
So should I keep it at 1a for now or get a better charger?
You can probably just put in 5A for both packs and the charger will try to do its best.
A better charger would let you charge more quickly, but both are fine for the batteries.
If you have the budget, a good charger is about the closest thing to an 'investment' in this hobby. A good, powerful, multichannel charger will be something you will use for years, for all your RC needs. Keep that 25w per cell rule in mind, though. Some multi channel chargers only list total wattage, and if you have 2 or 4 4s or 6s packs, that 25w per cell quickly climbs to be a very large number...
- Thread starter
- #15
Does arrma do nitro?
CrashBoom
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Regardless of what max charging rate is given, it's generally best to top out at 1C.
The faster you charge, the more strain it puts on the battery and shortens its life. Your 3S 5,000mah 3C charge rate battery CAN be charged at 15 amps for 30 mins but if you charge it at 1.2amps for four hours you'll probably get more than twice the life from it before it is knackered.
slick2500
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Ditch the wall charger they are not that great to be honest most charge at like 0.1amps. The last one I had took 9 hours to charge the 900mah battery.
https://www.arrmaforum.com/threads/recommend-me-a-battery-charger.1079/
