I would like to give you 4 suggestions:
The first point is that cell phone lithium batteries do not support high current discharge because they are lithium-ion batteries, not to mention that the 3800 mAh must be a false standard. Do you want to have such a large capacity? When the power runs out, the battery swells and you can't have the cake and eat it too. It is recommended to purchase a regular 18650 battery, which should last a while, but ultimately it is recommended to purchase nickel-metal hydride, which is cheap and can discharge at high currents (18650). but for safety or performance reasons, I suggest you buy a special battery. The high-power model aircraft motor consumes a lot of current and cannot afford to damage it. Plus, model airplanes aren't just for hours of playing. If you really wantplaying, playing with oil is pretty good.
Second, if you want your own DIY charger, I suggest you go to the official website of Maxim or Linear to find chips dedicated to charging lithium batteries and solder a board yourself . I've had lithium batteries explode when. I charged them myself, so be careful and carry a 3A protection card. There is no problem charging together in series, but this requires protective plates between the batteries.
Third, the nickel-metal hydride battery charger should not be used to charge lithium batteries, because the charging methods are different, so do not connect it, otherwise it will shorten the service life of the lithium battery. you don't connect the protection board, then you just risk the flowers.
Fourth, I played with model airplanes before, but not anymore Haha, itIt is important to pay attention to safety. Cheapness and convenience are both fish and cake, unless you have certain abilities and knowledge. So I can't explain it completely clearly, so if you don't understand, don't hesitate to ask. I'm an electronics student and I like tinkering with little things. Hehe~~~~~
I'm a DIY novice and I have 16 3.2V 15Ah lithium iron phosphate batteries. How to charge a single battery and discharge it to test capacity
Main materials:
1. Carbon anode material: The anode materials actually used in lithium-ion batteries are mainly carbon materials, such as artificial graphite and natural graphite. , mesophase carbon microspheres, petroleum coke, carbon fiber, carbon pyrolytic resin, etc.
2. Tin-based negative electrode materials: Tin-based negative electrode materials can be divided into two types: tin oxide and tin-based composite oxide. Oxides refer to oxides of metallic tin in various valence states. There are no commercial products.
3. Nitride: There are no commercial products.
4. Alloys: including tin-based alloys, silicon-based alloys, germanium-based alloys, aluminum-based alloys, antimony-based alloys, magnesium-based alloys and others is an alloy and has no commercial product.
To proPos the problem of paralleling two strings of 7.4V lithium batteries
It would be much easier to manage if there was a dedicated battery discharge meter. Otherwise, at least a universal watch, heating wire, alligator clips and a piece of 2㎡ thick wire.
Use wires to connect two alligator clips to create two or four clips. First use one end to tighten one end of the heating wire, the other end to tighten the negative electrode of the battery and the other end. First attach the positive terminal of the battery and attach one end to the multimeter. Use the multimeter to measure the current. If the current is large, extend the distance between the two clips (i.e. move the clips, never pull). the heating wire). You know you need the power, then attach it directly to the heating wire. The capacity must be converted. Generally speaking, a bNational standard 10 amp hour battery should be discharged with a current of 5 amps for 120 minutes for a new 20 amp hour battery. 10 amps for 120 minutes.
It is possible to use cell phone lithium batteries to DIY batteries. Multiple batteries can be connected in parallel and then connected in series, like two strings. The maximum voltage is 8.4V. shown in the picture.
Use 7.4V battery composed of 6 batteries, so DIY battery needs to pay attention to:
1 .The capacity of each parallel battery should be the same as possible; 2. It is better to add an equalizer. Avoid overloading a certain voltage group.