why are there MaH and A on my battery

[SunEagle]

I'm glad you are in the same hobby, i was asking about the solar battery on the plane to operate, its a glider so i have surface area to work with for panels, now for the topic of a charger station, is there a way to build a solar/battery set up that charges batteries, i don't mind if it takes double the time, i charge 8 batteries at a time with my HiTec charger:

http://hitecrcd.com/products/chargers/discontinued-chargers-charging-accessories/x4-multi-charger/product

I see people bringing lead acid batteries to the field and charging, so i believe we cant be that far off when charging via solar.

There have been a number of RC pilots that have built solar gliders. The biggest problem is to get any good charging you need to cover the entire upper surface with cells, but the extra weight makes the plane heavier thus needing more boost or much better thermals.

Where I have seen solar work is on a large "powered" glider. That allows the flyer to only use the electric motor to run the prop a short time to gain lift and the cells can put back some of what is used.

No one has built a solar plane that can charge the batteries faster then they are discharged so unless the wind is in your favor and you find them thermals your plane will eventually land.

So like Sunking said the best way to fly RC is to have a lot of extra LiPo's in your bag.

Although I did build a small solar / battery system to charge my LiPo's at fields that don't have power. It was fun to build but kind of expensive at around $500.

[Sunking]

I see people bringing lead acid batteries to the field and charging, so i believe we cant be that far off when charging via solar.

No where close or practical. Your Hitech charger, and such chargers are made to operate from a stiff source of power. Stiff source means it can provide any amount of power required indefinitely. Solar is not a stiff source. At any point in time the amount of power is unknown other than it WILL NOT BE say 100 watts on a 100 watt panel ever. Only at noon will a panel produce its maximum power and that is only for a few precious minutes. Your charger would not work period. That is why the Lead Acid battery or some kind of buffer battery is required.

With 8 charging ports, you just made it 8 times more impossible. That is why you see people bring large lead acid batteries to charge their LiPo batteries. Exact same reason our flying club uses one. It is the only way to make it work economically.

Now it is possible to do with solar if you have design experience, money is no object, and throw practicality out the window. Give you an example. Say you have a small charger like a iCharger 1010B+ a 300 watt charger. Solar panels output power varies with the intensity of the sun. A 100 watt panel in the morning starts out with a few watts in the morning and builds gradually until noon when it peaks at 80 to 85 watts assuming crystal clear blue skies. After noon power fades to 0 watts by sunset. The iCharger needs 300 watts available anytime while in use. The only way to do that is if you used a grossly over sized panel of say 1000 to 1500 watts.

Next challenge is you would need to design and build a custom regulator to interface the panel to the charger.

As you can see that is just not realistic. The best way is to do what I did. Use a moderate sized panel of say 500 watts with a conventional solar charge controller and a 24 volt lead acid battery. A 24 volt 100 AH Pb battery on a full charge can handle as many 3S to 6S batteries you can throw at it in a busy weekend. At the end of the Sunday would be fairly deeply discharged around 50% discharged. But like any club is only busy on weekends. The panel has all week long to recover for the next weekend. That system cost me $1000 to construct. The bad news about the system is it can only handle one charger at a time. I don't use it. I charge at home, I have over a hundred LiPo batteries. I can fly all day long with only a few minutes between flights. Just enough time to cool the motors and change out batteries.

There is one other way, but requires a solid design experience. Still have to use an grossly over sized panel. The trick is to design a charge controller to charge the LiPo's directly. That is no easy project and requires a lot of DC to DC Power Converter design experience and a means to fabricate the circuit board. I am a professional electrical engineer of 40 years and would not take it on unless it is for a production model. It would hundreds of hours of my time. My time is worth $100/hour or more.

So what you are seeing is smart money. Guys buy a pair of 6-volt golf cart batteries or a smaller 12 volt deep cycle battery, an inexpensive AC charger to charge the battery at home, and take to the field. If you went solar requiires the same battery plus a whole lot more money for the solar that does not work out like you think.

[J.P.M.]

And i look at all sources before committing to a project.

Me too. I always check the National Enquirer along with other sources for reliable information. I, like you it seems, practice real and critical discernment of sources.

I'd also respectfully suggest you check you first post for caps, syntax and sentence before throwing too many stones. Just sayin'.

[Tesla]

U-tube: The new Idiot's' bible.

haha i like your quote....well at least THIS idiot spelled YouTube correctly.

And i look at all sources before committing to a project.

[Tesla]

Good ole Youtube, the Idiots Bible.


I fly 3D RC Planes and the last thing you want to do is use solar to charge your Rc LiPo batteries. Why would you want to wait all day to charge a battery? Even after a day may not be fully charged.

Our club does have a Solar Rig to charge LiPo batteries. I built and designed it. It is a 500 watt panel with a 24 volt 100 AH lead acid battery and uses PL8 Hobby Charger. The secret to it is the Lead Acid Battery, the panel cannot supply the 1300 watts the charger can demand. Trust me all us club members would throw that solar system away in a heartbeat for good ole AC power. With the solar system only one lousy battery can be charged up at a time. Does not work so good with more than one pilot trying to fly and charge batteries. The lead acid battery does the real work and charging.

The real solution to flying electric planes is to have 5 to 10 batteries and take them with you fully charged.

I'm glad you are in the same hobby, i was asking about the solar battery on the plane to operate, its a glider so i have surface area to work with for panels, now for the topic of a charger station, is there a way to build a solar/battery set up that charges batteries, i don't mind if it takes double the time, i charge 8 batteries at a time with my HiTec charger:

http://hitecrcd.com/products/chargers/discontinued-chargers-charging-accessories/x4-multi-charger/product

I see people bringing lead acid batteries to the field and charging, so i believe we cant be that far off when charging via solar.

[Sunking]

U-tube: The new Idiot's' bible.

Yeah I ripped you off. I like it.

[Sunking]

Thanks for everyone's feedback, my end goal is to take all electronics i use every day and build a solar panel and battery system for them, i watched a YouTube video of a guy with a camper that does just that, he used a camera charger in his description along with laptops, fans, heaters ...etc, so i used the camera charger.

Good ole Youtube, the Idiots Bible.

I fly R/C gliders that are electric and thought it would be cool to make one solar/battery powered , i mean i only get 20 minutes flight from one on a regular LiPo battery so i can be that off if i do solar with batteries.

I fly 3D RC Planes and the last thing you want to do is use solar to charge your Rc LiPo batteries. Why would you want to wait all day to charge a battery? Even after a day may not be fully charged.

Our club does have a Solar Rig to charge LiPo batteries. I built and designed it. It is a 500 watt panel with a 24 volt 100 AH lead acid battery and uses PL8 Hobby Charger. The secret to it is the Lead Acid Battery, the panel cannot supply the 1300 watts the charger can demand. Trust me all us club members would throw that solar system away in a heartbeat for good ole AC power. With the solar system only one lousy battery can be charged up at a time. Does not work so good with more than one pilot trying to fly and charge batteries. The lead acid battery does the real work and charging.

The real solution to flying electric planes is to have 5 to 10 batteries and take them with you fully charged.

[J.P.M.]

Thanks for everyone's feedback, my end goal is to take all electronics i use every day and build a solar panel and battery system for them, i watched a YouTube video of a guy with a camper that does just that, he used a camera charger in his description along with laptops, fans, heaters ...etc, so i used the camera charger.

But 18650's are awesome for holding charge and are lighter compared to traditional acid batteries plus maintenance free.

I fly R/C gliders that are electric and thought it would be cool to make one solar/battery powered , i mean i only get 20 minutes flight from one on a regualr LiPo battery so i can be that off if i do solar with batteries.

U-tube: The new Idiot's' bible.

[Tesla]

Thanks for everyone's feedback, my end goal is to take all electronics i use every day and build a solar panel and battery system for them, i watched a YouTube video of a guy with a camper that does just that, he used a camera charger in his description along with laptops, fans, heaters ...etc, so i used the camera charger.

But 18650's are awesome for holding charge and are lighter compared to traditional acid batteries plus maintenance free.

I fly R/C gliders that are electric and thought it would be cool to make one solar/battery powered , i mean i only get 20 minutes flight from one on a regualr LiPo battery so i can be that off if i do solar with batteries.

[Sunking]

Go it, so if my camera charger was 500ma...how would you calculate the discharge rate ?

Does not compute, nor does anyone need to know. A camera discharge rate is so low, it cannot be measured.

Battery capacity is specified in Amp Hours at some Discharge Rate. In the case of lithium, they fudge all the numbers. However 90% of all other batteries are rated at a 20 hour discharge rate. It is all extremely complicated math. It takes 20 years of higher education to understand if you are educated in the USA, 5th grade math in any other country. So here you go.

Amp Hours = Amps x Hours, or AH = A x H
Hours = Amp Hours / Amps, or H = AH/A
Amps = Amp Hours / Hours, or A = AH/H

So in theory lets say you have a 200 AH Flooded Lead Acid Battery at the 20 hour discharge rate. What does that mean. Well if discharged at the 20 hour rate it means 200 AH / 20 H = 10 amps, or it means the battery can supply 10 amps for 20 hours. However that is only theory because the same battery if discharged at say the 1 hour rate is only a 85 AH battery meaning it can only supply 85 amps fpr 1 hour or a 85 AH battery at the 1 hour rate. What happened to the missing 115 AH? Nothing, Peukert Law kicked in.

Here is the deal. There are different battery chemistries. Each chemistry has it own application. A camera has almost no real demand for power, so it uses a lithium or alkalyne battery that cannot supply a high rate of power. An electric vehicle demands huge amounts of power and requires a special chemistry to deliver very high C-Rates.

I am not going to bother educating you, not my job. If you want a starter try this link as it defines some common terms. Read it then come back with questions. Or you can read what pretenders think.

OK the answer to your question is simple.

Camera charger AC 100V-240V 50/60Hz
output DC 8.4V----500Ma

Simply means the charger is 8.4 volts with a maximum charge current of 500 ma. So if the battery in the camera were 2 AH or 2000 mah and completely discharge would take 4+ hours to charge. 2000 mah / 500 ma = 4 hours.

[AzRoute66]

The battery charger puts out a maximum of one half amp (500 mA) at 8.4 VDC. This is the rate that current goes INTO the battery.

The power coming OUT of the battery has to do with discharge. The battery will supply [allegedly] 20A continuous or 35A pulse, in your case [camera] the continuous would never be nearly that high, and the pulse might be when your 10 lb flash goes off and starts to recharge.

Not sure what to say about charging an 18650 at 8.4 VDC. I suspect one of us is not quite getting the 'picture'. Picture, get it? I crack myself up.

[sensij]

Go it, so if my camera charger was 500ma...how would you calculate the discharge rate ?

Camera charger AC 100V-240V 50/60Hz
output DC 8.4V----500Ma

and if it dosen't apply to this charger i gave specs for, then when would the 35A max discharge work ?

I'm not really following what you want to do. In the first post, you talked about replacing lead acid with these. Were you using the lead acid as an energy source to recharge your camera through an inverter, and then an AC/DC adapter? How many of these 18650 cells are you intending to use, in what configuration?

[Tesla]

The 3000 mAh is the capacity of the battery. The 35A is a max discharge rate, usually a very short duration. The max continuous current on those batteries is 20A, according to the specs - this rate wouldn't be supported much longer than the 35A though.

Go it, so if my camera charger was 500ma...how would you calculate the discharge rate ?

Camera charger AC 100V-240V 50/60Hz
output DC 8.4V----500Ma

and if it dosen't apply to this charger i gave specs for, then when would the 35A max discharge work ?

[Mike90250]

Just to re-iterate, these cells are rated for only 20 A continuous discharge, a rate of 6.67C, the 9 minute rate. The 35 A on the label is a *pulse* discharge only, just a couple seconds at most. These cells are not designed to be discharged heavily at 10C or more, and definitely not short circuited.........

I was going too say pretty much the same thing, nobody really knows what some random Mfg prints on the label. Yes there are standards, but if they aren't followed, you can't rely on them being implemented. With so much counterfeiting and 800mA ups-man-ship "My cells are bigger than your cells" going on, beware.

[sensij]

The 3000 mAh is the capacity of the battery. The 35A is a max discharge rate, usually a very short duration. The max continuous current on those batteries is 20A, according to the specs - this rate wouldn't be supported much longer than the 35A though.

Just to re-iterate, these cells are rated for only 20 A continuous discharge, a rate of 6.67C, the 9 minute rate. The 35 A on the label is a *pulse* discharge only, just a couple seconds at most. These cells are not designed to be discharged heavily at 10C or more, and definitely not short circuited... a dangerous overheating condition will occur, and long term damage done to the battery.

Real world bench test results of this particular cell are posted here.