tommynash

iTrader: (8)

How do they work? And what are the benefits of using a power supply vs a standard charger?

mushroomed

iTrader: (8)

You plug in the power supply to a 110v/220v source and it will output somewhere between 12v and 20V.

You can connect battery chargers, tire warmers, some soldering irons to the power supply. You can do this with multiple devices at the same time. Usually the connection is made with 4mm banana plugs connectors.

If you get a high power / high current power supply it can outlast your chargers or other accessories. It means that the devices can be smaller because they don't need to include a power supply circuit.

tommynash

iTrader: (8)

So can you hook up any charger to a power supply and charge at higher volts?

froggie22

iTrader: (4)

No not quite.

An AC charger has a power supply built it. (1 that plugs straight into the wall)

A DC charger needs a separate power supply (or a big 12-20v battery) as it does not have one built in.
By making a charger DC, manufactures can reduce the size of the charger and not limit themselves to small built in power supplies.

So if you have an AC charger, a power supply will do nothing for you.

My ST-RR EVO

iTrader: (5)

A power supply converts ac current (the type of current that comes out of your wall or extension cord) to DC current (the type of current that comes out of your full size car battery or any battery for that matter). The benefit of a separate power supply is the wattage they make. A 1200 watt power supply can charge batteries a lot faster than say a HiTech x4 ac / dc charger that only pumps out 50 watts per channel. My opinion is that a high performing power supply should be built into the charger. I don't want to be carrying around two separate items. I'm assuming batteries need to be charged by dc current.

tommynash

iTrader: (8)

thanks for the info!

platgof

iTrader: (4)

Once you try a DC charger and power supply, you will understand that it is the better system to use. You pay way more for the convenience of a built in power supply. They usually are very weak and don't last very long either. Pick up a converted computer power supply, and a decent charger like a 206B, and you are way ahead of the game. The trade offs for a built in power supply are not worth it. Almost all AC chargers have a system that allows an out side source as well(DC voltage,) and a higher charge rate as well.

Roelof

Depends which charger....

A lot of AC/DC chargers can not charge at full power on their own power supply

platgof

iTrader: (4)

That is how they fool people. A lot of times they tell you what their ac/dc charger can do with an external power supply, slick. AC/DC chargers are a waste of money in the long run. I use an HP 750 computer power supply that does 62.5 amps @ 750 watts. Find out how much you pay for an ac/dc charger with that much power? My cost for the unit and parts to modify it, $25. The charger I use(Junsi 206B) cost $115 at A Main with a $10 discount. It does 20 amps. I can run two of these off my power supply. So find out how much a 40 amp ac/dc dual charging system would cost? My total is $255, and if a part goes bad....mine is way easier to replace. When you use a better charging system, you need fewer batteries to be ready for the next race, as they charge very fast. I use to buy two batteries at a time when I raced because my ac/dc charger was that slow, now I just buy one battery per car. Makes this hobby a lot cheaper. When you see the size of an HP 750 power supply, you will be surprised how small it is, and the Junsi is a little smaller, great system.

RLPowerSupplies

An AC/DC charger will run cooler and better when used with a external DC power supply

JerryRigged

iTrader: (2)

The bolded section is not correct. A power supply CANNOT charge a battery without a charger. and then, you are limited by what the CHARGER can output, not the PS.

Example - If you have a 1200W PS, and a 50W DC charger, you will only be able to charge at 50w max. That 50w charger will never charge a 4s pack above 3.4a, regardless of the PS size...

Also the opposite is true too - the charger can only output what the PS can supply. I currently have a charger capable of outputting a total of 600w, but my PS is limited to about 330 watts - so I must pay attention an not set my charge rates too high and overload the PS.

To charge at high wattage / hi amperage, you need a BOTH a PS and a charger that are rated for the desired charging rates.

The math is pretty simple. Amps X Volts = Watts. or Watts/volts = amps.

So if you have a 4s 5000mah pack, and want to charge at 1c /5a, the math is -
5a * 14.4v = 72w - you need 72watts of power to charge that battery at 1c/5a.

One more "Got-ya" when shopping chargers - multi-channel chargers will sometimes be rated by their TOTAL wattage, when each channel can't use that full wattage. Example - my old charger was a 2 channel, "100w" charger. It could charge 2 batteries separately , to a TOTAL of 100w. Charging only one battery, though, it could only charge 50w.

Some 4 channel, 50w per channel charges are sold as "200w" chargers, but they can only put 50w to each channel...

Example - This Charger is listed as a "320w" charger - it says 320w all over the add copy, but each channel can only make 80w - 80w x 4 channels =320w, so they are not wrong. To me, however, it is a bit deceptive.

Be sure to read into the specs to see what the amperage and wattage is for each channel.

GuyIsDamGood

I agree once again. The Graupner Polaron EX 1400 with the Graupner Polaron power supply(2012) is better than the Hitec X1 Pro with 17amp ePowerbox power supply.

(The Hitec X1 Pro can't display the battery non-charging voltage).

biz77

iTrader: (47)

This is not really correct as a blanket statement. As it pertains to the LiPo batteries we use predominately in RC, I will mostly agree with your statement however as I would never use anything but a dedicated charger with algorithms designed specifically for charging lithium cells.
I have used a Rivergate 30-amp power supply, a competition electronics 24-amp power supply and a Muchmore Powermaster to charge 12-volt car batteries throughout the years. A charger is basically a power supply with more sophisticated circuitry. If you have a power supply with both variable voltage and current, you can easily charge a wide range of batteries. Here is a how-to:
http://www.learningaboutelectronics....C-power-supply

As others have stated, the primary reason these days for a separate DC power supply is to have more power on tap. Chargers with AC input (AKA built-in power supply) are usually relegated to charging at relatively low power compared to their DC counterparts. The largest I recall seeing is the single output Turnigy Rekator 20-amp/300 watt. While this is quite powerful for an AC charger, it is small compared to something like an iCharger 406DUO, which has dual outputs with up to 40 amps (1,000 watts) of charging power each.
We would probably need to look back to the roots of RC to see why most stuff runs on DC power. Back in the day our tracks were temporary setups in parking lots and the like. The only power available was the battery under the hood of your real car, so necessarily everything ran off 12 volt DC power. As we evolved and started building permanent outdoor and even indoor tracks AC power was more accessible, but we already had all of these 12-volt DC devices, so the obvious answer was the 12-volt power supply adopted to our hobby.
To this day, I'm guessing there are still quite a few facilities where people are bringing generators or large deep cycle batteries to power their DC chargers, tire truers, pit lights etc because AC power is not easily accessible. Perhaps they race at a different indoor facility in the winter where AC power is readily available. You wouldn't want to buy all the same gear twice - one set for outdoor use on DC power and one set for indoor use on AC power, so the power supply makes perfect sense. It's a lot smaller and lighter than lugging a deep cycle 12-volt battery into the pit area.
In my personal pit area, my power supply typically runs my charger, pit light and tire truer. Back in the day of NiCd and NiMh batteries and brushed motors you could find a few more items running off power supplies like comm lathes and discharging/balancing trays. If each of these devices needed their own built-in supply they would physically all be much larger.

GuyIsDamGood

The Graupner and Hitec power supplies can charge from a USB output. . .How?

Thanks

Grizzbob

iTrader: (2)

If you're wondering about powering a charger through its USB port, or charging batteries from that alone, it doesn't. It's just a USB port, & can only power devices that are meant to run off a USB port(like the charge cable from your phone, or MP3 player, etc.). It's just a 5V, 1 amp current through a USB port....