Sandrelis76
Member
- Messages
- 45
- Reaction score
- 5
- Arrma RC's
- Kraton 6s
Kraton Blx185
- Thread starter Sandrelis76
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
links, including eBay, Amazon, and others.
- Messages
- 1,755
- Reaction score
- 3,176
- Location
- Wenatchee, WA
- Arrma RC's
- 4x4-Mega
- BigRock 4x4
- Felony
- Granite
- Infraction
- Limitless
- Kraton 6s
- Outcast 4s
- Typhon 3s
- Voltage
I've seen people run 6700mah but I personally wouldn't run more than 6000mah due to added weight and also longer run time = more heat. Ideal charge rate is 1c so 5A for a 5000mah pack however you can charge larger mah packs at less than 1c rate just fine it just takes longer you just don't want to charge too fast is all.
DynaRy
Member
As far as I know mAh has nothing to do with how many amps you could pull from a battery. It’s the amount of power stored into a battery. So a 5000mAh LIPO has power to power up a unit which has a amp draw of 5Amp the provided LIPO wil run for about an hour or so.
What you want to know is the Amp draw from the BLX185. In the manual they state you need a lipo on 4S or 6S with a C rating of min 35C on a 5000mAh pack. The continues Amp draw of the BLX185 is 150Amp. (Check manual).
I have 3S LIPO and 6S LIPO on 50C with 8000mAh. They’re just bigger and run longer and nearly fit inside the battery mount of the car. Downside, they’re big, heavy and expensive. As of the max mAh the BLX can take is limitless. It will just run longer. (But watch out for the Motor and ESC temps as you run longer without a break)
If you could charge a bigger Amp LIPO on a smaller Amp charger uts possible and is without risc. It only takes longer to max out the charge.
This link to instrucables will explain A lot more about LIPO and charging. (There are many others, just search google)
https://www.instructables.com/id/Lithium-Polymer-Etiquette/
What you want to know is the Amp draw from the BLX185. In the manual they state you need a lipo on 4S or 6S with a C rating of min 35C on a 5000mAh pack. The continues Amp draw of the BLX185 is 150Amp. (Check manual).
I have 3S LIPO and 6S LIPO on 50C with 8000mAh. They’re just bigger and run longer and nearly fit inside the battery mount of the car. Downside, they’re big, heavy and expensive. As of the max mAh the BLX can take is limitless. It will just run longer. (But watch out for the Motor and ESC temps as you run longer without a break)
If you could charge a bigger Amp LIPO on a smaller Amp charger uts possible and is without risc. It only takes longer to max out the charge.
This link to instrucables will explain A lot more about LIPO and charging. (There are many others, just search google)
https://www.instructables.com/id/Lithium-Polymer-Etiquette/
As others have said, MAH is the size of the gas tank, making it bigger will not effect the ESC/Motor, other than give more run time. Make it smaller, and if you make it too small, you can reduce the amp capacity of the battery, which will have negative effects on the power system.
As a rule of thumb, for a 5a charge rate, you need 25w PER CELL. So a 50w charger is good for a 2s lipo. (2 * 25 = 50) If you are charging a 6s, you need 150w (6 * 25 = 150)
Why 5 amps? For a 5000mah battery, 5a is "1C" charge rate, and will charge the battery in about one hour, and 5000mah is common for our RC's. If you want to go big, like that 8000mah above, you will want a 8a charge rate. The math to figure out wattage -
cell voltage * charge rate * safety factor = wattage
so
4.2 * 8 * 1.2 = 40w per cell.
So for 8000mah packs, if you have 3s packs, you need 120w to charge at 8a. To charge a 8000mah 6s, you need 240w.
Why do I add a safety factor? so you don't burn out your charger in a year. Also, if you use your charger in the garage, or outside, the heat will reduce the safe power level your charger can handle.
Last - yes, you can run a 50w charger at 50w/2.4a and charge a 6s 8000mah pack. But you will reduce your chargers life running it that way, and it will take about 3 hours to charge that battery. The Lipo will be fine, though. No danger there.
Need more info - how many cells, and what is the charger wattage?
As a rule of thumb, for a 5a charge rate, you need 25w PER CELL. So a 50w charger is good for a 2s lipo. (2 * 25 = 50) If you are charging a 6s, you need 150w (6 * 25 = 150)
Why 5 amps? For a 5000mah battery, 5a is "1C" charge rate, and will charge the battery in about one hour, and 5000mah is common for our RC's. If you want to go big, like that 8000mah above, you will want a 8a charge rate. The math to figure out wattage -
cell voltage * charge rate * safety factor = wattage
so
4.2 * 8 * 1.2 = 40w per cell.
So for 8000mah packs, if you have 3s packs, you need 120w to charge at 8a. To charge a 8000mah 6s, you need 240w.
Why do I add a safety factor? so you don't burn out your charger in a year. Also, if you use your charger in the garage, or outside, the heat will reduce the safe power level your charger can handle.
Last - yes, you can run a 50w charger at 50w/2.4a and charge a 6s 8000mah pack. But you will reduce your chargers life running it that way, and it will take about 3 hours to charge that battery. The Lipo will be fine, though. No danger there.
