Charles,

OK, I'm looking at a 150 watt (max) draw from the charger. I don't have the batteries to make it work nearly that hard, so I'll probably start with the little battery and 1.5 amp charger. The largest cells I'm currently charging are 1,650mA 3S lipos, but this will increase over time.

Yeah, until you do the math, it's hard to visualize the amps you can draw at low (12) volts. 150 watts at 12 volts is ~12.5 amps. That's a lot of current when you are used to thinking of 150 watts at 120V, where it's only ~1.25 amps.

I was planning on keeping my DVM on the battery the first few times to be sure it stayed in the acceptable range. I"ll give it a shot with the little battery first and see how it fares. If it's stuggling at all, I have a decent full sized battery and 15 amp charger. It's just that much more mass to deal with.

My biggest concern was to verify that the battery would filter effectively. I kind-of knew it would but wanted to be sure.

I appreciate the quick and complete response.

Thank you,

Jack
ps - I read your "How Big" thread and I'm thinking 3 cells, 1,650 mA lipo should pull about one amp (3 x .33Ah), so I "should" be fine. We'll see.

I have a model train transformer that I'd like to use as a power supply, but I don't know the amperage. It goes up to 18VDC on the controller so I just dial it in until I read 13.8V on my meter. How do I know how many amps it's delivering, though? My charger takes 12-16V and 1.2A. My meter supposedly checks amps, but I don't know how to use it I guess. I moved the red lead to the 10A hole and touch the output on my power pack, but it shows 0. Am I misunderstanding how this is supposed to work? Thanks.

Pat

Your ammeter needs to be in series between the charger and the battery.

KC

Originally Posted by KC

Your ammeter needs to be in series between the charger and the battery.

Ah! It'll only show a reading when there's a load? But what if it's delivering too much and blows up my battery? Is there any way to simulate a load before I charge my battery into it? Thanks.

In the first place a model rail road transformer is not a well filtered power source and would be a very bad idea to try and use as a power source for any decent hobby charger.

Secondly a power supply or a car battery etc. can not deliever more current to a charger than the charger is trying to use.


Charles

Scratch the train transformer... Ah, I see what you're saying. How about a computer power supply? I've got several that deliver 12VDC 20A.... would that work ok? I like trying to use whatever I've got lying around in my shop, but not if it won't work properly or be a hazard. I apologize for my ignorance.

Pat

If you're looking for a powersupply, PM me.

I've got 8 computer power supplies in my shop and I was going to make one. I found some good links on how to use those. Sorry I ask so many questions before I search for previous posts.

And how about a Charger with a Power Supply Built in like this:

IMAX B6 AC - https://www.hobbyking.com/hobbyking/..._GENUINE_.html

Isn't it a bit more convenient to use 2 in 1? ?
( I mean for those who do not use Car Battery to charge)

Silly question.. how to know is the are Genuine or not ?

More convenient but just be aware that AC/DC chargers are less capacity for the same size as they have to fit the AC->DC circuit in as well. This one is only a 50 Watt capacity charger for example.

Originally Posted by Gnascimento3

And how about a Charger with a Power Supply Built in like this:

IMAX B6 AC - https://www.hobbyking.com/hobbyking/..._GENUINE_.html

Isn't it a bit more convenient to use 2 in 1? ?
( I mean for those who do not use Car Battery to charge)

Silly question.. how to know is the are Genuine or not ?

Originally Posted by jj604

More convenient but just be aware that AC/DC chargers are less capacity for the same size as they have to fit the AC->DC circuit in as well. This one is only a 50 Watt capacity charger for example.

I see... then could you recommend me a combo ?

BackGround is:

- I've got - 3 batteries 2200mAh 3s Lipo.
- I want to change them 3 at the same time on a Parallel Board
- Voltage of my wall-Line is 220v, (But some times o go to Brazil and there is 110v)

So which combo (PS+Charger) works well for this situation? my budget is not very high... any suggestion?

I don't recommend charger supply combos but here's what you need to think about.

First step is to figure out how big a charger you need:

1) 3x 2200 packs is 6600mAh. Or 6.6Ah.

2) If you want to charge at the 2C rate which is normal these days you need a charger that will supply 2x 6.6 = 13.2Amps.

3) It has to do this into a 3S pack which has voltage of 3x 4.2 = 12.6V when fully charged.

4) So the output power you need is13.2 x 12.6 = 166 Watts. You can use a smaller charger by charging at a slower rate. At 1C (which is what many people do) you would only need an 83 Watt charger but it would take twice as long to charge.

In round figures though I would look for a 150 Watt charger if you want to parallel charge and get your packs fully charged in under half an hour.

Not many AC/DC chargers will have this capacity. For example this HobbyKing charger looks close - it is a 130 Watt charger but that is only when powered from a DC supply. On AC it is only a 60 Watt charger. This might be OK if you only need the AC option occasionally.

https://www.hobbyking.com/hobbyking/s...cessories.html

For travelling having just a single charger rather than a separate power supply saves a lot of hassle and you might be happy to compromise on charging time. AC/DC chargers normally all work on any line voltage from 100-240V.

Not sure what you mean by "budget is not very high". That is a personal judgment.

You want power, reliability, and cheap? Pick any two.

A good buy at the moment is the Hyperion 0720i NET-AD which is a sophisticated highly regarded charger that does 150W on DC and 90W on AC. It is selling for around $110.

http://www.aircraft-world.com/shopexd.asp?id=3086

I doubt you will get a power supply/charger combo that does 150 Watts for much less.

The iCharger 106B is a highly regarded 250Watt/10 Amp DC charger which HobbyKing sell for about $80 but you need to add a power supply. The cheapest HobbyKing have that will do what you want is this one for $40 and it has poor reviews for safety.

https://www.hobbyking.com/hobbyking/...e_Charger.html

https://www.hobbyking.com/hobbyking/...ers_350W_.html

A popular option instead of parallel charging is one of the multiport chargers like this.

https://www.hobbyking.com/hobbyking/...k_Charger.html

They are only 50 Watt/circuit but that is adequate for a single 3S 2200 at the 2C rate. And you can do up to four at a time. You still need a 250Watt power supply however.

Originally Posted by Gnascimento3

I see... then could you recommend me a combo ?

BackGround is:

- I've got - 3 batteries 2200mAh 3s Lipo.
- I want to change them 3 at the same time on a Parallel Board
- Voltage of my wall-Line is 220v, (But some times o go to Brazil and there is 110v)

So which combo (PS+Charger) works well for this situation? my budget is not very high... any suggestion?

Mate.. it was awesome tip.... better... a class !!!!

Probably a multport plus a power supply is a good option to work with !!!!!


By the way I love Australia.. I lived for 4 years in there, hope I will fly some planes over there one day !!!!


Thank u a lot for the clarify....

Personally, if you are likely to only use the 3S 2200 size pack I would consider the 4 port chargers. There are a few around and you should check reviews/comments on the Internet. There seem to be only two or three variations under a number of different brand names.

The big advantages over parallel charging are:

1) It is intrinsically a bit safer
2) You don't have the extra parallel board to carry around.
3) You can charge 4 packs at totally different states if charge.

3 is the really important one IMO.

Downside is that you have less flexibility. They are 4x 50 Watt chargers in one box. You cannot use the full 200 Watt capacity to charge a bigger pack if you ever go to larger ones.

Well I know it might be repetitive but how about this one:

Hyperion Eos 730i Net3
http://www.amazon.com/gp/product/B00...=AKOFZ2K334IOY