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charger input voltage

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Old 01-10-2019, 01:27 AM
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Default charger input voltage

Thinking of getting the icharger X6. It said the input voltage is up to 32dcv. Got some questions and thanks in advance for using with 7.4v touring battery:

1. For charging 7.4v lipo, does input 32v do any advantage?
2. What should be the power supply i need?
3. What is the charging voltage for 7.4v lipo

I heard people said, connect a 32v power supply to charger and charge a battery then your battery has more punch then using 12v power supply. Is this non sense?

Quote"
  • X6 uses advanced Synchronous buck-boost DC/DC converter technology with high power, high current and high-performance power conversion circuit. The maximum charge power capacity is up to 800W, the maximum charge/discharge current of a channel is up to 30A.
  • X6 Supports 6s LiPo, Lilo, LiFe, LiHV, LTO and NiZn batteries, with maximum 2A balance current, and adopts a unique balance calculation of internal resistance correction. Supports 1-20s NiMH/NiCd batteries and 1-12s Pb batteries.
  • With digital-power mode for great protection (over-current protection, over-voltage protection, input under-voltage protection, input undercurrent protection, and etc.)
  • Intelligent fan control. Sensing internal temperature via the internal temperature sensor, to thereby control the fan speed.
  • Internal temperature protection. When the internal temperature exceeds the Power Reduce temperature, the output power is automatically reduced; and the charger will shut down when temperature exceeds the Shut-down temperature.
  • This charger can save 32 parameters sets and support the data import/export to SD card. 7. A 2.4" IPS LCD screen provides rich information including current, voltage, power, capacity, internal resistance, control status, time-consuming and temperature, etc.
  • Multi-discharge features: self-discharge, regenerative to input discharge, and lithium battery extra expanding discharge.
  • Supports measurement for internal resistance of battery offline and online. Can measure not only the internal resistance of the entire battery pack, but also measure the internal resistance of each cell within the lithium battery.
  • X6 has protection for reversed polarity (input or output), input voltage/current, battery temperature, charging capacity, overrun time and maximum power etc.
  • Supports upgrading the hardware program by USB port or SD card. X6 also supports the “Junsi Console” software and can display, plot and analyze the charge and discharge data by it.




Specifications:
Net weight: 168g
Dimension: 83x65x37 ±0.5mm
Input Voltage Range: 10.0—32.0VDC
Maximum Input Current Limit: <35A
Maximum Charge/Discharge Current: 30A
Maximum Charge Power Capacity: 800W
Maximum Discharge Power Capacity: 30W
Maximum Regenerative Discharge Power Capacity: 800W
Maximum Extra Discharge Power Capacity: 900W @30V/30A
Maximum Current Drain for Balancing: >2A
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Old 01-10-2019, 02:05 AM
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No sense at all...

The charger brings back the voltage to 2S charging voltage, so 8.4~8.44v
Because you can calculate in charging wattage you can use a lower current power supply with 32v than with 12v

If you have more devices on 12v I would go with a 12v power supply.
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Old 01-10-2019, 02:10 AM
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Originally Posted by Roelof View Post
No sense at all...

The charger brings back the voltage to 2S charging voltage, so 8.4~8.44v
Because you can calculate in charging wattage you can use a lower current power supply with 32v than with 12v

If you have more devices on 12v I would go with a 12v power supply.
I think I read somewhere that the X6 can only do the higher charge rates when the PSU voltage is 24V or more.
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Old 01-10-2019, 04:01 AM
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Originally Posted by gigaplex View Post
I think I read somewhere that the X6 can only do the higher charge rates when the PSU voltage is 24V or more.
I can charge my 2s lipos at 20amps with mine. I haven't had a reason to really try charging any higher than that. So I'm not sure what the limit is on a 12v PS.
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Old 01-10-2019, 04:02 AM
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I've got a 30a 12v power supply and I can charge a 2s at 25a all day long. Haven't gone higher because 4c is usually as high as I go.
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Old 01-10-2019, 04:10 AM
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most chargers NEED 3 volts higher then the battery charger voltage... so 8.4 volts plus 3 volts is 11.4 volts.. so a 12 volt charger with the proper amperage needed.

everything else is just a waste of money. and not used or needed..

and the person that said a higher voltage into the charger "PUSHES" has no clue about electronics. my opinion.
50 years in the electronic business.
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Old 01-10-2019, 04:32 AM
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Originally Posted by chuck_thehammer View Post
most chargers NEED 3 volts higher then the battery charger voltage... so 8.4 volts plus 3 volts is 11.4 volts.. so a 12 volt charger with the proper amperage needed.

everything else is just a waste of money. and not used or needed..

and the person that said a higher voltage into the charger "PUSHES" has no clue about electronics. my opinion.
50 years in the electronic business.
The X6 can actually charge 4S packs with only 12V input as it has an internal step up converter. Maybe it was that configuration that requires the higher input voltage for the higher currents that I read about.
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Old 01-10-2019, 05:10 AM
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Originally Posted by chuck_thehammer View Post
most chargers NEED 3 volts higher then the battery charger voltage... so 8.4 volts plus 3 volts is 11.4 volts.. so a 12 volt charger with the proper amperage needed.

everything else is just a waste of money. and not used or needed..

and the person that said a higher voltage into the charger "PUSHES" has no clue about electronics. my opinion.
50 years in the electronic business.
Older NiMh chargers had a lineair current circuit that required some volts above battery voltage to work correctly. All current chargers work with a switching voltage regulator which do not need a power voltage above battery voltage
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Old 01-11-2019, 06:50 AM
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Thanks all.

I use only 20amp charge the most. So, I just keep using my 30A 12v ps would be enough. thanks all
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Old 01-11-2019, 03:58 PM
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believe what you want.

Last edited by chuck_thehammer; 01-11-2019 at 04:54 PM.
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Old 01-11-2019, 05:08 PM
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I will do one of my typical "over answers"
If it doesn't make sense at first, come back to it over time and it will make more sense.
First of all, don't worry about the charge voltage actually going to the battery. The charger will take care of that as long as you have the balance connector hooked up. The charger will autodetect your battery and charge it with the correct voltage and current program.

So about the input voltage. There is a basic formula for electrical power:
Power=Volts*Current

So if you go look at the ratings you posted in your first post, you will see that charger is rated at 800W. If you want 800Watts out, you need a little more than 800Watts in.

So the input current required for 800 Watts out depends on the input voltage. I (in) =800/V
So if you have a 24 volts supply, 800/24=33 Amps. If you want to run your changer at full power and buy a 24 V supply, it has to be rated at more than 33amps.
If you have a 12V supply, 800/12=66 amps! If you halve, the voltage, you have to double the current.
BUT!!! go back and look at your specs. The maximum input current is 35 Amps which is much less than 66amps.

So what does that mean? It means that with a 12V supply, the charger will not be able to operate at full power. 12V*35Amps= 420 Watts, or about half power. These chargers are quite smart. They will automatically not overdrive themselves. If you set a charging current that exceeds any of the charger's ratings, it will throttle itself.

So bottom line is if you buy that charger and buy ANY 12volt supply, you will only get at most about half the total power.

But how much power do you need? It depends on the S# of your battery, the battery capacity, and how fast you want to charge. You didn't mention what batteries you will be charging but I will give you some examples:
2S 5000: 2S voltage is about 8Volts. To charge that battery at 2C requires 10 amps. P=IV as always so 8V*10amps =80 watts. So 400 watts would be plenty for that.
6S 5000: You would need three times more power or 240 watts. Even at 3C, 25 volts*15amps=375 but that is pretty close to the limit for 12V input.

800watts is a lot of power, especially for 2S batteries. They just don't need a lot of power to charge at pretty high current.

So buy what you are willing to pay for and lug around. A 12V 500 Watt supply would be ok but if you want a true match to that charger, you need at least 24 Volts and at least 800 Watts. Look at the progressiveRC.com combos and see what supplies they match up with various chargers. That will give you a good idea.
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Old 01-12-2019, 01:29 AM
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Nice explenation but The maximum power needed @30A is about 255 watt with the mentioned 2S batteries. The charger has a limitation of 30A and that with 8.4v charging voltage makes it not even the 400w. The needed input current @12v will be about 12A which is also far below the max spec of 35A

Then again, the starting post was talking about more punch when the charger is connected to a higer voltage, cut how? The charger is working far below its maximum specs so how can the extra punch on a higer input voltage be created if the output to the battery will be the same?
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Old 01-12-2019, 04:10 AM
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from 1988 to sale.. I designed switcher supplies, power distributions systems, constant current chargers, analog to digital and digital to analog converter circuits.

the company I worked for was purchased by Texas Instruments in 2003

2 hours with an electronics book will educate you on simple electronic power units.

most of electronics is MATH.. and data sheets.

the amount of electric / electronic MIS-Information on the internet is just staggering..
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Old 01-12-2019, 12:19 PM
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Originally Posted by Roelof View Post
the starting post was talking about more punch when the charger is connected to a higer voltage
"punch" isn't a thing. The charger will charge your batteries the way you program it as long as none of its fundamental limits are exceeded which include max current out, Power, and max current In.
Maximum Input Current Limit: <35A
So 12V * 35A= 420 Watts. If you are charging 2S batteries 420Watts/8V=52.5A but
Maximum Charge/Discharge Current: 30A
so the charger will hit its output current limit before it hits its power limit.
30 amps of charging current is a lot and more than most people need.
30 amps* 8 volts= 240 Watts
So.... if you ONLY want to charge 2S batteries, a 12V supply over 240Watts would be a waste. But if you went to higher S#, then up to 400Watts 12 V supply would be useful.
If you want to run the charger at it's full 800W capacity (and I think most folks don't) then you need at least a 24V 800 Watt supply.

You don't get more "punch" with higher input voltage, just the capability to program higher charge rates for 4S and 6S batteries.

I will say it a different way. If you only want to charge 2S batteries, then there is not much point going to more than a 12V input supply.
Since the maximum output current is 30A no matter what, 8V*30A= 240W which can easily be supplied by a 12V power supply. 240W/12V=20Amps which is much less that Maximum Input Current Limit: <35A

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Old 01-12-2019, 12:38 PM
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All of the above is why I bought the Protek 625
https://www.amainhobbies.com/protek-...k-8519/p578442
There is not powersupply to buy because it is built in. It has duel 200W channels and is great for 2S and even 4S batteries. For 6S, it is under powered and I still use my i306B 1000W system for those.

For the OP, the X6 is probably a waste if he will be limited to 2S or 4S batteries unless he plans to do a lot of parallel charging. Something like the Protek 625 might be a better choice.

The X6 is $110. The total cost will depend on which supply he get but here is a 500W one for $90
https://www.progressiverc.com/prc-50...er-supply.html
So for $200 he gets one channel at 500W

With the Poteck 625, you get two 200W channels for $250
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