fbords

I recently got an eflite apprentice 15e as my first plane transitioning from helicopters. It comes with a 3 cell lipo that requires a 12v power source. What other options do you guys use that are fairly inexpensive as altnatives to using your car battery? I'd like the ability to charge it from a wall outlet at home as well.

Gray Beard

My Feedback: (-1)

Most of the better chargers are AC/DC, mine is just DC. I use one of the auto jump start batteries sold in any auto parts store to charge my packs. It has even been used to jump start a car or two at the field.

SBOT

Discarded printer power supply make very good power supplies for RC. I have one that I am using that puts out 12 volts at 4.1 amps. Another that I have outputs 16 volts at 1.6 amps. I never throw away a power supply with reading what the output is.

fbords

I capable enough to convert a power supply. Looks easy enough. My only issue is I don't have a voltage meter. The charger that came with the kit has a dial on it that goes up to 3 amps. If the power supply is 12 volts, 5 amps, will it damage the battery, or will the charger regulate the amperage?

opjose

You cannot safely charge a LiPo from a 12v source without some sort of intermediate LiPo charger.

12v may supply voltage to a charger... is that what you have in mind?

SBOT

Right, the charger will only use what it needs. The printer power supply will have a small schematic showing which wire supplies which volts; so a meter is not needed, but you should get one. It doesn't have to be the best you can buy, $10.00 units work just fine.

CGRetired

My Feedback: (1)

You beat me to it, Jose. I was wondering about that statement "12 volt source" to charge a LiPo battery. This technology requires, big REQUIRES a charger that is designed to charge LiPo battery packs. Trying to charge it otherwise could, probably would, cause the battery pack to disintegrate with devastating results.

CGr

blvdbuzzard

As stated, are you asking for a power supply to power a 3s lipo charger or are you thinking of using a 12v source to charge a 3s lipo battery. If you are plugging the lipo into a 12v power supply, I think you will let the magic smoke out real soon.

I have several PC power supplies I have converted to power my chargers. It cost about $10.00 to convert (2) power supplies.

There are a lot of budget priced chargers that are AC/DC.

Buzz.

SBOT

I cannot belive you think he is going to charge a battery straight off a power supply. Read the OP post; it is all right there.

CGRetired

My Feedback: (1)

Hey, I am not trying to raise issues, but what does that look like to you?

Our job, as both RC hobbyists and moderators, is to make sure the posters understand things, especially charging LiPo packs.

I, for one, would rather error on reading the post than give out false information. If he said "requires a 12v power source", that means to me that he wants to charge directly from a 12 volt source, which is not a good thing, so I would rather make sure he understands the process than let him connect a LiPo directly to a 12 volt source.

Understand?

I certainly hope so.

CGr.

fbords

Let me explain again. I have the below charger. I want to have another option to using the clips with my car battery. The PC power supply is a fine idea, my concern is that the instructions for the battery state not to use more than 3 amps when charging (which is as high as the dial on my charger goes). If I convert say a 12 volt, 5 amp PS for use with thered and black alligator clips on my charger, I was wondering if the 2 amp difference would be a problem. However, it looks like sbot answered my question. If the power is regulated by the charger, there shouldn't be an issue.

http://www.e-fliterc.com/Products/Default.aspx?ProdID=EFLC3010

SBOT

Sorry CG I know as a mod you do not have the time to read each post carefully. I was refering to post #4 last sentence. "or will the charger regulate the voltage" Besides you will always missunderstand if you only read one sentence of a post. I do not type fast enough to argue or discuss on line so I am sorry if I offend anyone, just seemed very clear to me.

CGRetired

My Feedback: (1)

Ok. Well, I was referring to the original post which made a statement that could - would confuse some as to how a LiPo was charged. I made that clear by quoting the origina post.

CGr

bingo field

It's ok, it is always better to be safe by fully understanding, than sorry. CG just wanted to ensure that you weren't going to charge those batteries incorrectly. That would be very likely to cause a fire. Those batteries can be hazardous if not charged with the correct type of charger. The goal is not to lose any aviators to errant electrons...[8D]

acdii

That charger is a POS, I know, I had one, gave it away and spent $50(although they now are $10 more) for a Thunder charger AC680 that charges the batteries quicker and safer.

The pack that came with my plane was a 3300 Mah, so 3 amp takes longer, and I charge mine at 3.5 amp.

Also the 3300 25C Gen Ace packs are a great buy for the plane, you can get up to 17 minute flights with one of those, and they are 1/3 the cost of the eflite pack.  I got both from Hobbypartz.

ec121

My Feedback: (2)

I convert PC power supplies. About $10 to convert one. Usually 8-10 amps. Or buy a used server power supply for $20 and get 20A.

warbird addict

Ac or Dc don't matter for me I bought a good beefy deep cycle marine battery and I wanna say like a 1000 watt inverter from pep boys for $200 for the pair you can charge and fly anything all weekend on a single charge of the marine battery and power 12 volt LED lighting in ur trailer, Husky also makes a 1000 watt 2 stroke generator with 1500 watt surge with breakers for like $249 which has both 12 volt and 120 volt plug ins with leads maybe a bit more expensive and less creative than a pc power supply but non the less a bullet proof solution that won't leave you stranded add a $69 ship n shore charger and you are 100% prepared to charge anything anywhere anytime

warbird addict

best part is the husky generator is 2 stroke and runs a 40:1 mix so you can use up ur old plane gas to run it on, I've powered camp lights, charged my van battery when I lost my alternater , charged the marine battery,cell phone batteries, etc

OliverJacob

My Feedback: (12)

You can use any power supply that delivers a higher current then the charger delivers to the battery. The voltage is what you need to watch out for. And make sure the output of the power supply says 'DC' and not 'AC'.
Another idea is to get a small 12 Volt battery, like you use for a lawn mower. There are cheap and last for some time. But a little on the heavy side...
But even better would be - toss the stock charger and get a decent one. They are well worth their money and your batteries will be treated better.

blvdbuzzard

I too had read it as RCG did. I do not want to see a lipo go up in smoke. When in doubt, ask.

Here is the site I followed to convert my extra PC power supplies.

http://web2.murraystate.edu/andy.bat...OWERSUPPLY.HTM

Budget power supplies

http://www.geeks.com/details.asp?inv...680-12&cat=PWR

Budget chargers.

http://www.hobbypartz.com/60p-dyc-10...rger-blue.html

I use this one for everything from 2s 460mah to my 6s 5500mah batteries. May only charge at 5 amps, but I have patience.
http://www.hobbypartz.com/60p-dyc-1004.html

Buzz.

fbords

Thanks guys, sorry for all the confusion. It was unfortunately one of those times whee my brain knew what I meant, but it got all messed up when I tried typing it. Lots of great suggestions. I think what I'll do is convert a power supply for now (mainly because it's a cool little project), and just buy a good charger that has all the leads I'm looking for, including a wall outlet. I suppose if I had one of those in the first place, this point would be moot anyway. 

opjose

Just don't do what that article in the link tells you to do, e.g. DO NOT "ZIP TIE" the resistor!

It gets VERY HOT and will melt the plastic.

I used metal heat sinks affixed with bolts to the side of the case and held the 10w resistor in place with a metal loop.

After years of use the heat sink looks like it's a bit burned, but otherwise everything works great.

Gray Beard

My Feedback: (-1)

Please tell me I didn't get your question wrong!! I thought it was pretty clear and simple, {{what do I use instead of opening the hood to my car and using the car battery to clip my charger to.}} Sounded simple to me unless I got it wrong. {That is happening a lot these days!} At the field the guys are using everything from there car battery to deep cell boat batteries. I just use the remote jump starter and I have also just added one of the ends onto my charger that will plug into an auto cigarette lighter. My van has outlets for computers and small tools. You were just looking for a power source, correct? I picked up the auto jump starter at Sears when it was on sale. I use it for a lot of things, engine starters, power for the power panel and my Lipo charger. Several times I have used it to start up cars and vans for fiends at the field. When I travel it is in the van or car with me so it isn't just an RC support item. They cost about $40.00 but can be found cheaper.
As a Mod in the beginners forum CG has to make sure everything is clear or someone may try to just hook up a pack to the car battery. If he didn't make it clear someone would try a direct hook up!