PlagueDoctor

Hello all!

I'm new here and just getting back into RC after a 10 yer hiatus. I'm seeing a bunch of new things around that weren't around 10 years ago. One of those things that are new for me are power supplies.

Back in the day you could just plug in a charger to the wall and start charging. Now I see chargers and power supplies. What is the point of having a power supply?? Do I have to have one if I get a high end charger? What else are they good for?

Can anyone help me out?
Thanks for your help!
-Plague


tl;dr: Whats the point of power supplies?

whitrzac

iTrader: (97)

there were no good chargers 10 years ago that were AC...

Today is no different.

AreCee

iTrader: (1)

Essentially wrong, but it's debatable.

I was using power supplies with DC chargers in the eighties so they have bee around for a long time.

A separate power supply allows you to have a clean, filtered souce of high current whereas AC chargers are limited to low power due to space limitations. You don't see many 30A or 40A AC chargers if any, most can barely handle 5A.

monkeyracing

iTrader: (10)

Unless you're charging at high amperage, there's no need for a charger with a separate power supply. There are plenty of good AC chargers available, but you won't find much beyond the 10a per channel range. That should be plenty for most people, especially when charging at 1C. If I'm running a couple of 5000mah packs at a race, I sure as heck don't need 20+ amps to deal with it.

From a more personal perspective, I think more than half the time I see someone at the track with separate power supplies, is because they're gear sluts (...or gear snobs. You pick). We've all been guilty of buying unnecessary crap at some point, because it looked cool or because someone else (probably a better racer) had one. I run an AC charger most of the time, but if I do take my other, higher output charger to the track, I power it with a black plastic brick, like you'd use for a laptop. Mine is a re-purposed unit from a satellite TV receiver. It puts out 18v at 7a. When I'm charging a 2s pack at 6.6a, it only draws about 3a from the supply, so there's plenty of headroom. If I need more, there's also my 500w computer power supply. I've never needed more, though.

PlagueDoctor

Thanks for the responses guys!
So essentially, power supplies are for charging at higher rates/currents than a regular AC charger can provide?
Is there any other use for them?

Meradin

iTrader: (19)

One big reason is that most of the chargers we are getting are direct from China units. Some are relabled but still...direct from China. If a charger is to be sold in the US and run from the wall circut (AC) it must have a UL listing and be tested by UL labs which increases the cost.

By not putting built-in power supplies they can produce a cheaper unit that has a smaller foot print.

PlagueDoctor

That's interesting. So they don't come with power supplies but can they still handle what a power supply delivers and are there any that should not be hooked up to a power supply?

USMC STONE

One thing I don't see mentioned that I use is a charger that can charge 2-4 batteries at a time at up to 6.5 amps each, you need a power supply to charge that many batteries at once. I run etruggy, ebuggy and 4x4sc plus nitro buggy and truggy. Not a equipment snob or whatever stupid opinion they had, it's what worked for me

mtpocketsracing

iTrader: (2)

also don't forget most of the ac chargers are dc also. you can do it either way.

ufoDziner

iTrader: (39)

I use power supplies because I need to charge up to 4 batteries at a time if we (wife and kids as well) are all driving at the same time and don't want it to take years to do. So, 4 batts at 10 Amps each is about the best I could find in a charger, and it runs on DC only.

PlagueDoctor

What charger do you use?

Dave H

Good question, comes up frequently, not sure there is a definitive answer. Suspect some of it is simply historical, as early on most if not all chargers were DC only. There are possible advantages to separate supplies though.

Over time chargers have changed many times, charge cords, timers, delta peak, different delta for nimh, delta with model memories, lipo, lipo with balancing (still waiting for dilithium crystals lol). Power supplies have essentially changed once, going from linear to switch mode based. Allows for updating chargers without replacing the supply as battery tech progresses.

As mentioned many (most?) chargers with built in supplies have a supply just barely big enough. Lots of times at races many guys are running off a circuit, perhaps on long extension cords, with chargers switching off and on, can be tough on power supplies. I’ve seen too many chargers with blown supplies that end up being over-weight sized priced DC chargers. I’ve rarely seen a charger fail. Significantly more powerful likely more robust power supplies are available for similar or perhaps slightly more total cost than a roughly equivalent AC/DC. Since many hobbyists end up with more than one charger it quite possibly ends up cheaper.

A DC charger is more compact, handier to move around the pit table, from close to the car to out of the way for example. Other stuff that can use the power supply includes tire warmers, dischargers (ok sort of obsolete), engine heaters I think, sure I’m overlooking some stuff. Availability, I haven’t noticed much of a difference in offerings over a significantly longer time frame than mentioned. Making broad physiological observations based on charger power selection: Priceless!

Cheers all.

yoshgixxer

iTrader: (78)

think its more to do with AC (altering current) is always fluctuating from 0-170v.. And the voltage travels in both directions in the wire..ever notice your lights dim in your house out of no were?..not a very stable power source for charging sensitive packs and having to provide consistant amperage..it also degrades over longer distances

DC (direct current) electric was discoverd by tesla (if you care) and maintains its voltage 100% better then AC,and only travels in one direction, 12V Will stay 12v start to finish and dosnt degrade in voltage. Much cleaner supply of electric for our sensitive electronics..

I also agree with the theory of not havning to be UL cert as part of the reasoning.but over all i believe its the clean stability is the main reasoning behind needing power supplies..

welp hope i didnt bore to much lol

GLwagon

iTrader: (22)

A long long time ago far far away....
We didn't have A/C power where we raced or flew planes.
Many batteries were & are charged off of big old 12v car batteries.

Until the age of digital power supplies even a little 10amp unit weighed as much as a six pack of soda & was just as big.
My old 30amp was as big as a cinder block & just as heavy.

Yes, the best chargers are D/C too.
From a sales/marketing point raising the price for adding the guts of a D/C supply to chargers isn't needed for people who charge off of car batteries in the middle of nowhere, & also those who hook 4-5 chargers off of 1 big honkin' supply.

The point of an external supply? most people don't have A/C power where they play, & they don't need one.

ufoDziner

iTrader: (39)

PowerLab 8