Charger

[canadianbikeguy]

Hobbyking - Whats the difference between Charger/Balancer and Charger/Discharger/Balancer and Charger/Discharger?

Explain what is bulk charging? I can only assume that it is not seperating the pack every time you want to charge up your batteries. And I do this after I balance charge my new batteries, or do I balance charge them a few times and discharge them either through the charger/discharging unit or riding.

I am looking at a "Genuine" IMAX B6-AC, Charger/Disharger 1-6 cells, 50W max charge, 5W max discharge and 0.1 to 1A charge current for $45. This would seem like it would take forever to charge the battery, which is good I guess having a slow charge. Whats a happy medium for charger choice? I dont mind going a Power Supply Route hooked up to the charger. A computer 12V power supply would be my second ideal choice.

6S = 11.1V and I want a 44.4 volt system I would have to break this 44.4V pack into 4 then charge each one after the other with only one charger. I am looking at having four of the Turnigy 6S 11.1V 6Ah to 8Ah range with a 25C to 50C rating, which the C rating is actually somewhat less from what I read here on ES. I read somewhere too that some particular chargers would always run the fan when it was charging. I would totally do the BBQ charging thing while home for peace of mind as I tend to be a little bit OCD.

Another general newbie question would be, I understand watt-hours, is like your gas tank. Depending on the terrain, hills, wind, throttle position you use more or less watt-hours until your batteries go below the low cutoff voltage if I have a BMS, if not I would need some sort of guage and I need to keep an eye on it, otherwise I damage my batteries, reducing the life span. so with the previous battery setup of a total of 44.4V 8Ah 25-50C, would give me 355Wh. Which in turn gives me a certain distance. Now lets say I go 44.4V at 2Ah 25-50C = 89Wh, theoretically would give me X amount of kilometers or miles. Would having that 2Ah setup, being stupid as it is, damage the batteries in any way.

And finally how long would it take to charge a 44.4V 8Ah with that previous charger I mentioned.

 

[wesnewell]

If you want to run a 12s pack (44.4V nominal) and charge with an rc charger, then best choice would be the Thunder 1220 12s charger. You could charge an 8ah 12s pack in a little over an hour with the 300W thunder 1220 charging as 12s. Using the 50W imax 6BAC will take ~8 hours to charge and you'll have to parallel charge as 6s.

If you have a 48V controller, its LVC of 42V will keep you from over discharging a 12s pack. But this makes a good cheap fuel gauge. Hook up on controller side.
http://www.ebay.com/itm/Waterproof-Digital-Voltmeter-15V-To-120V-Red-Led-Voltage-Digital-Panel-Meter-G9-/161078127200

A 2ah battery pack is not a good idea. Don't go under 5ah of 20C which would be rated for 100A continuous and 150A burst. A 5ah 12s pack will generally give you a 10mile range @ 20mph. I'll let you convert to km.

 

[dogman dan]

Wes is recommending a very good choice.

If you are on that tight a budget, at least get yourself a faster charger than a 50w charger. A b6 is just too damn slow.

I have two cheap Turnigy accucell 8 chargers that have served me well. At 150w, at least it charges a 10 ah 6s pack in a reasonable time. Having two of them, I can charge at a 300 watt rate. If you connect all your packs in parallel, you can charge them all at once, or even charge and balance them all at once on just one charger.

If you have a 12s 10 ah pack, it's about 440 wh, so you will get charged fast enough to stand it with a 150 or 200w charger. Avoid the quad chargers, they are notorious for not working well.

Bulk charging is any charge that does not balance, and connects on the main wires. So when I use my Turnigy charger, and do not select balance charge, I'm bulk charging.

You can also bulk charge a larger pack with a regular lithium charger, the kind normally used with a bms equipped pack. I would not recommend any noob to start out with bulk charging. You want to be very knowlegable about lico, and know for a fact every cell in your pack is good before start bulk charging without a bms.

I recommend all users of RC packs, noobs and experts alike, to never store or charge them in a place where you would not start a fire.

 

[izeman]

agreed with all written above except this: 6s is NOT 11.1v but 22-25v depending on soc. nominal is 22.2 and fully charged 25.
so you need 12s to have 44-50v.
but maybe you already know that and it was just a typo.

 

[dogman dan]

Re the 2 ah question, the lower the size the lower the total amps you get at a given c rate.

IMO, the 20c RC packs need to be discharged at 5c max, unless you like a ton of voltage sag that makes the pack hot and cuts it's lifespan a lot.

2 ah x 5c is only 10 amps. So that's limiting your controller size a lot. For that reason, a 5 ah pack is about the minimum I will ever run, and even then I will use a smaller 25 amps controller. 5 ah x 5c is 25 amps. I still see plenty of voltage sag on my 25 amps bike, when I use the 5 ah pack. For a 40 amps controller, 10 ah is the minimum I will run.

5 ah gets me about 6 miles without discharging the pack too deep. But I can push it to 8 miles if I must. That's such a short range, a healthy person could just pedal it easy.

 

[canadianbikeguy]

Avoid the quad chargers, they are notorious for not working well.

Is this like a HobbyKing Quattro 4x6S Lithium Polymer Multi Charger where there are 4 inputs for charging seperate packs?


I found this one. Turnigy dlux ACDC 130W 10A 6S $55, so what would you say it should take what about 3 hours with the batteries in parallel, charging. I am either going to have four 3S 11.1V Turnigy batteries, or two 6S 22.2V Turnigy batteries. Depending on the price differences.

If you connect all your packs in parallel, you can charge them all at once, or even charge and balance them all at once on just one charger.

Here is the link for the charger
http://www.hobbyking.com/hobbyking/...ance_Charger_Discharger_with_Accessories.html

 

[dogman dan]

As good as any choice, in the bargain charger category. I have two of the cheap turnigy 150w chargers that have, rather amazingly, both worked fine for years. I can't say about that particular model. You get one, and find out if it's good or not. That seems pretty universal for all chargers, including some very expensive ones.

Anyway, assuming you will be running a 12s 10 ah pack, that's about 450 watt hours. So 450 divided by 130 is about 3 hours and 45 min for a non balancing charge. Balancing can take a lot longer since it happens at about 5 watts.

So that charger will do.

The problem with a 200w Quattro charger is that it's just 4 incredibly shoddy chargers in one box. One better charger that puts out 130 w is a better choice. You might get a second 130w charger later, if you have a power supply able to put out 300w or more. Then you'd be charging your pack in well under 2 hours. This is important with lico, you simply cannot safely put the thing on the charger and go to bed.