Charger AC adapter question

[jchandler]

Since the BNF 450x doesn't come with a power supply for the charger I have found two ac adapters that may work. Which one should I use?

1. 12V DC 4.0A

or

2. 12V DC 500mA

[Gawl]

I wouldn't use any but the one specifically for that charger, but thats just me.

[jchandler]

I wish it would have came with one

[rpmrpm]

The E-flite unit (EFLC4030) is a 12v 3.0amp unit. So as long as you have a output plug of the proper size and polarity (positive on the center lug) then your first choice (4.0amp) would meet the requirements. Although I just got the E-flite unit to leave at work w/the stock charger. .

[Talesin]

500mA would charge incredibly slowly, if it would power on at all.
4A would be acceptable.

Most important is the voltage and polarity, honestly. Voltage can safely be between 11.5-15V, with the center pin being positive. Many people have older laptop power supplies that will fit and work.

It's over-voltage, not over-amperage (except in EXTREME cases) that kills electronics. A supply providing 19V, or with negative center pin, or with 40A would all toast the stock charger pretty quick, if not instantly.

Really though, if you don't have a supply hanging around that you can re/dual-purpose, the actual, official, warrantied AC adapter brick is only about $22 at most hobby shops. To me it was worth that bit of extra peace-of-mind (that and all of my old laptop power supplies that would actually fit the plug are all outputting 19V).

[weld8704]

The Blade 450 X charger is a 1.8A charger, it's not variable rate. If you connect it to a 500mA power supply, the charger will kill the power supply as soon as you connect it.

[jchandler]

I've charged two batteries with the 4A power sup. seems to be working great.

[ehasoon]

The manual specified that a '3.0 amp minimum' power supply is needed, so your 4 amp is definitely fine. I'm in the process of converting a PC power supply for use with my charger (purchase pending) .

[Talesin]

Originally Posted by ehasoon

The manual specified that a '3.0 amp minimum' power supply is needed, so your 4 amp is definitely fine. I'm in the process of converting a PC power supply for use with my charger (purchase pending) .

Hrm. Speaking of which, what's the upper safe-amperage limit? Just realized that I do have a few spare PC PSUs laying around, and wouldn't be too much trouble to hack one up, remove (most of) the molex connectors and just wire up direct lugs to the 12V rails. Actually could do the same with a USB connector or four to the 5V rail, and have some use for a little 200-350W cheapo premade-system unit that'll easily put out 12V@10-25A, and would otherwise have just ended up chucked in the trash.

[Mega Stumbler]

There is no upper limit when it comes to amperage. The amperage rating is the max output of the power supply. it is not what the supply always puts out because the attached circuit (charger) only uses the amps it needs. If there was a max then the hundreds or thousands of people that run chargers off of vehicle batteries capable of 500 amps or more would be ruining their equipment.

Their equipment survives just fine.

I personally use a converted xbox 360 power supply (16A @ 12VDC) and a converted atx power supply (12A at 12VDC) to run my chargers big and small.

Sent from my DROIDX using Tapatalk

[Kumba]

Originally Posted by Mega Stumbler

There is no upper limit when it comes to amperage. The amperage rating is the max output of the power supply. it is not what the supply always puts out because the attached circuit (charger) only uses the amps it needs. If there was a max then the hundreds or thousands of people that run chargers off of vehicle batteries capable of 500 amps or more would be ruining their equipment.

What he said. You can hook your charger to a 3000-amp power supply and it will be just fine. Voltage and Current (AC/DC) are what has to match. Amperage is just a measure of consumption. An electronic device is only going to consume so much, no matter what it's consumable supply is.

The bigger problem is that almost all DC power supplies are switch mode power supplies. This means that they require a certain amount of load to work right. If your PSU requires 30% of it's 12v load to be consumed to output a proper 12-volts then there is your problem with using a huge amperage supply. With a conventional linear power supply you don't have this issue. Instead you would have a 50-pound brick to carry around. That's why switch mode is so popular. Small and light weight.

[TDMModels]

When you get multiple battery packs, you are going to want to do parralell charging. To do that, you need a power supply and charger that can provide at least 20 amps.
I use a 250 watt pc power supply and an I charger 206b. You can buy a package deal like link below.


http://www.progressiverc.com/the-ticket-350w-combo.html

[rc-bender]

Originally Posted by TDMModels

When you get multiple battery packs, you are going to want to do parralell charging. To do that, you need a power supply and charger that can provide at least 20 amps.
I use a 250 watt pc power supply and an I charger 206b. You can buy a package deal like link below.


http://www.progressiverc.com/the-ticket-350w-combo.html

+1

That's exactly what you want.

[vyper2k1]

I found a power supply from an old hp laop top i have that fits the stock 300x charger perfectly. When i connected it to the charger all the lights indicated that everything was fine and it was charging. I still unplugged it because i read in the pack of the power supply that it had an output of 19V 7.1A the input was 100-240v ~1.5A 50-60Hz. Anyone know if i should continue to use this as a power supply or if it is too much and will fry my adapter and charger?

[Offset]

The front of the charger says 11.5v-15v DC input so anything higher than 15 volts is hazardous. The device will draw as much amperage as it needs but you really need at least 3.5amp to power this charger, otherwise it will just cut off and on when it ramps up the charge cycle.

These chargers do balance but they do not balance well. Some units will give you under 4.20v per cell while some will give you upwards of 4.26. Approaching 4.3 is bad for the life of the battery and is considered overcharging which can be hazardous.

You'll want to get something like an iCharger before you start investing in too many batteries.

Be safe!

[Offset]

Originally Posted by vyper2k1

I found a power supply from an old hp laop top i have that fits the stock 300x charger perfectly. When i connected it to the charger all the lights indicated that everything was fine and it was charging. I still unplugged it because i read in the pack of the power supply that it had an output of 19V 7.1A the input was 100-240v ~1.5A 50-60Hz. Anyone know if i should continue to use this as a power supply or if it is too much and will fry my adapter and charger?

Not a good idea. While voltages do vary among devices and they are designed with these variances in mind, a power supply rated at 19v may actually be anywhere around 19v so it could be running as high as 20-21v. Or a tad lower too.

Either way this power supply is too hot and you may burn up the charger at best. A fire is the worst outcome. Or the charger will work fine for years to come. It's hard to say without actually opening one and referencing all the wires and circuits.

But it is a risk nonetheless.

Be safe!

[vyper2k1]

Thanks for the info. Much appreciated.