Author Topic: What to look for in a charger. (Read 2911 times)

Randy Powell · « **on:** July 28, 2013, 04:33:29 PM »

So, I've read a ton on chargers but I'm still not sure what I should be looking for. I am a complete neophyte at electrics and while I can follow directions (I bought motor, ESC, timer and batteries based on what I was told by local experts). But I'd like to get better at figuring stuff out. When buying a charger, what should one look for. Most advertise a bunch of capabilities but I'm not at all sure which ones I need. What are the critical elements? What features are the most important?

Thanks.

Mark Scarborough · « **Reply #1 on:** July 28, 2013, 04:45:07 PM »

It has to be able to charge batteries,, thats pretty important

Mark Scarborough · « **Reply #2 on:** July 28, 2013, 04:51:50 PM »

ok ok,,
so you want to be able to charge at a minimum of 1C,, so for a 5S pack,, nominally 3000 mah,, you need to charge at 3 amps, for 1C,, or 4.5 amps for 1.5 C,,,, most chargers rate their charge capacity by watts,, soooo

4.5 amps * 18.8 volts = aprox 85 watts minimum,,
or 6 amps* 18.8 volts= 112 watts for a 2C charge
being able to DISCHARGE to storage voltage is a nice benefit,,
Balancing is paramount,,so some chargers offer built in balancing,, some use an external balancer like the Equinox balancer,, less convenient,, but functional

John Cralley · « **Reply #3 on:** July 28, 2013, 05:21:50 PM »

Quote from: Mark Scarborough on July 28, 2013, 04:51:50 PM

being able to DISCHARGE to storage voltage is a nice benefit,,
Balancing is paramount,,so some chargers offer built in balancing,,

Mark is right on but I would say that being able to discharge and CHARGE to storage level is ESSENTIAL or else you will have to fool around getting your batteries to storage charge.

As long as you are buying a new charger get one that will balance without fooling with external balancers.

Tim Wescott · « **Reply #4 on:** July 28, 2013, 05:58:31 PM »

Generally what I look for in a charger is electronic components. If you peer inside and see raisins and dead mice and stuff like that you've definitely bought the wrong thing.

What Mark said. I'd make sure that you get one that can charge more cells than you think you'll use, that does balancing, and that has enough power to charge your packs before the sun sets. Being able to charge multiple packs at once is a nice feature, but maybe not absolutely necessary.

Dan Bregar · « **Reply #5 on:** July 28, 2013, 06:03:09 PM »

Randy

I certainly agree with John about being able to charge & discharge to storage level. It's also very very nice to be able to charge more than one pack at a time. Say 2, 3, 4 or more packs at a time. Which means more power. I would suggest a charger that has at least a 20 amp output. 30 amps or more would be better. I used to take all day Saturday to charge 6 batteries so I could be ready to fly Sunday morning. My charger maxed out at 4 amps. Now I charge 7 battery packs Sunday morning before leaving the house for the flying field, and it only takes a little over 1 hr of charging time with my 30 amp charger. I could never go back !

Randy Powell · « **Reply #6 on:** July 29, 2013, 09:28:19 AM »

So, a lot of specs look like this:

Spec.
Input voltage range : 10.0 – 18.0VDC
Charge current range : 0.05 – 10.0A
Discharge current range : 0.05 – 7.0A
Maximum charge power capacity : 250W @ input voltage > 13.5V
Maximum discharge power capacity : 20W
Maximum extern discharge power capacity : 170W @ 20V/7A
Current drain for balancing : <300mA
Balance accuracy : <10mV
Lithium (LiPo/LiIo/LiFe) battery cell count : 1 – 6 series
NiCd/NiMH battery cell count : 1 – 17 series
Pb battery cell count : 1 – 12 series (2 – 24V)
Battery setup memories : 10
Intelligent temperature control : Yes
PC Connect : USB port
Weight : 350g
Dimensions (L X W X D) : 134X83X25mm

So, this is max discharge of 20W. I take it 30W would be better. Any other thoughts I'm not sure about things like if it is compatible with my batteries.

This is just an example, but looking at this, which parts are critical?

Howard Rush · « **Reply #7 on:** July 29, 2013, 10:34:35 AM »

One could just get a charger that other people with similar systems recommend, but that would go against your penchant for originality.

I guess I'd avoid getting a cheap one that would cause your batteries to spew fire. Being able to follow directions won't help much (in my opinion) with a Powerlab 6. I like the Thunder Power 820CD.

Randy Powell · « **Reply #8 on:** July 29, 2013, 11:30:29 AM »

Howard,

I do listen. I have had 5 different recommendations from 4 different "experts" (one has recommended two different chargers). I'll admit that I would like to find something that doesn't cost a $300 dollar bill like the system you are recommending, but I don't want one that will, as you say, spew fire either. I was just trying to get an idea of what capabilities would be desired versus stuff that might me nice to have but not really needed. At least initially.

Dan Bregar · « **Reply #9 on:** July 29, 2013, 03:45:39 PM »

Randy

I'm not an expert, but am fairly familiar with what kind of chargers are out there today, and which ones are well suited for our purposes. Here is a link for one that will do a fine job for you and it doesn't cost an arm and a leg. http://www.buddyrc.com/medias/downloadable/manual/junsi/206B%20V1.6.pdf 300 watts and 20 amps, and will work on any lipo pack you are likely to use in a stunter these days. Very capable for not much money. Will charge multiple packs at the same time for speed and convenience. Will charge & discharge to storage voltage. Also can be used with a 12 volt or a 24 volt power supply. You should check it out.

And for a few bucks more you can get the 306B, which is what I have been using for the last year.

Also this particular source gives a 1 year warranty on the charger and a 2 yr. warranty on most power supplies. You could do a lot worse

Dennis Toth · « **Reply #10 on:** July 29, 2013, 05:32:54 PM »

Randy,
The most important thing you buy for electric is the charger. You want a unit that is safe when charging your packs. The trouble people had with the Lipo's when they first started using them was from the charger (so did Boeing). A cheap charger with marginal components could cause a pack to incinerate.

Check some of the battery manufacture site for there recommendations (on the Thunder Power site they give specific brands they don't recommend) but you can't go wrong with the Thunder Power line of chargers. I like the TP610C - AC/DC. It has the wall plug power supply built in, it also can be clamped to a 12 volt charging batter for field use. It will charge any pack the Thunder Power or any other brand has and is not to pricey.

Best, DennisT

Randy Powell · « **Reply #11 on:** July 30, 2013, 09:35:17 AM »

Thanks for the information. One of the things I was wondering about was charging at the field versus at home and did you need two different chargers.

John Cralley · « **Reply #12 on:** July 30, 2013, 09:47:51 AM »

Quote from: Randy Powell on July 30, 2013, 09:35:17 AM

Thanks for the information. One of the things I was wondering about was charging at the field versus at home and did you need two different chargers.

Randy, The answer is no for most chargers. Most chargers accept a DC source such as a battery (car or marine) or generator that puts out DC in the proper range. With a generator you can also use your regular 110 to DC power supply with your charger. Ideally your flying site will have regular 110 source available but many do not. Some fliers use their regular car battery but you must use care to not run you car's battery too low which is hard on the battery and may leave you needing a jump to get your car started.

Tim Wescott · « **Reply #13 on:** July 30, 2013, 10:22:55 AM »

Quote from: John Cralley on July 30, 2013, 09:47:51 AM

Randy, The answer is no for most chargers. Most chargers accept a DC source such as a battery (car or marine) or generator that puts out DC in the proper range.

Or a suitable DC supply that runs off of house current. My charger (Triton II) is happy with a home-made 13.5V supply I made for ham radio use, you'll see folks talking about converting PC power supplies.

Note that it's easy to get a 12V DC supply, but that 12V can be low for some chargers (if your "12V" car battery is only putting out 12V then it's sick). So you need to pay close attention to the charger and supply specs.

Howard Rush · « **Reply #14 on:** July 30, 2013, 11:07:05 AM »

I wouldn't pay much extra for a charger that works both from house current and from 12V DC. For $30 delivered to your door you can get the powerful server power supply that Wm. DeMauro recommended. Then you can use the same charger at the field and at the house.

John Cralley · « **Reply #15 on:** July 30, 2013, 12:46:13 PM »

What Howard says.

Randy Powell · « **Reply #16 on:** July 31, 2013, 11:59:31 AM »

PC power supplies I got. Several from 250W to 500W (I've built a lot of computers). Looks like I'll be doing a bit of scavenging.

Thanks for the info.

John Cralley · « **Reply #17 on:** July 31, 2013, 12:55:29 PM »

Randy, There are good threads on RCUniverse and WattFlyer on how to convert a PC power supply for powering a charger.

Here is one link on conversion. http://web2.murraystate.edu/andy.batts/ps/powersupply.htm

William DeMauro · « **Reply #18 on:** July 31, 2013, 04:21:05 PM »

Depending on the charger that you get a pc power supply may not be powerful enough. That why many of us are using Server power supply's. Most of those will run the small as well as the larger chargers with no effort.

Randy Powell · « **Reply #19 on:** July 31, 2013, 04:28:53 PM »

I suspect a 500W supply will work. If not I have an Apevia job that is 1100W. I would think that would work.

Thanks for the link.

Dennis Toth · « **Reply #20 on:** July 31, 2013, 05:22:00 PM »

Randy,
I like the TP610C - AC/DC. It is very convenient when going to contest as it is one unit no extra equipment to forget in the shop. It has the wall plug power supply built in, it also can be clamped to a 12 volt charging batter for charging at the field. It will charge any pack the Thunder Power or any other brand has and is not to pricey.

If you spend money on any part of the electric setup spend it on the charger.

Best, DennisT

John Rist · « **Reply #21 on:** August 03, 2013, 04:05:25 PM »

24V DC 14.6A 350W Regulated Switching Power Supply

http://www.ebay.com/itm/190880063885?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

It looks like the above power supply should power a iCharger 206B 300W 20A 6S Balance Charger

True?
At $26 looks like a good deal. Appears all you need is a power coard.

I do have a question about the 206B the way I read it only will do a high discharge rate if powered from a car battery. True?

William DeMauro · « **Reply #22 on:** August 03, 2013, 05:57:54 PM »

John,
The 206b will do a regenerative discharge at a high rate providing you have a discharged car battery to put it into.

Peter Ferguson · « **Reply #23 on:** August 06, 2013, 04:20:15 PM »

I second Dennis's suggestion I have one and it works great. plugs into the wall or the car.

Peter Ferguson · « **Reply #24 on:** September 06, 2013, 08:27:42 PM »

I'm taking back my recommendation. I started thinking about all of the out of balance and balance connection messages I've gotten plus the shorting out of the balancer board due to bad solder joints and I think you can do better.

Randy Powell · « **Reply #25 on:** September 07, 2013, 06:38:48 PM »

OK, I went with the Thunderpower job. Hey, it's my first.