EEWORLD DIY------Converting Lead-acid Battery Flashlights to Lithium-ion Battery

ddllxxrr

EEWORLD DIY------Converting Lead-acid Battery Flashlights to Lithium-ion Battery [Copy link]

 

I hate things that are not useful. I have a big flashlight in my hand, and I have never used it, so I put it in the cabinet. Yesterday, I needed some lighting for an emergency, but it was useless in one day. I wanted to charge it for an hour before using it, so I plugged in the charging cable. However, when I went to check the situation half an hour later, I found that the whole flashlight was hot and had a smell. I opened it and found that it was full of battery fluid and the battery was deformed. I secretly hated the manufacturer for producing such a broken thing. I have some time today, so I want to repair this battery of mine. See if it can be repaired. I have a 3.7V 1800MA lithium battery with charging protection. The one below is a 200MA one. I just posted a picture. The one I have is a 1800MA one. Unopened flashlight: Disassembled flashlight: You can see that the battery has been deformed and there is a bag on it. Add my own lithium battery: Since the original shell has a slot, I can just plug my lithium battery in. Since the charging light diode and the current limiting resistor were also burned. (I found out from the data that it is 330 ohms) I replaced it with a 330 resistor and a red diode. Then I measured the voltage when charging and it was about 4V, which was just right for charging my 3.7V lithium battery. After the modification, I measured it before closing the shell and the voltage was normal. After closing the shell and plugging in the 220V charging cable, my flashlight was full of power. Euler!!! The road is uneven and someone shovels it. I am very dissatisfied with the lead-acid batteries used by manufacturers. We should be honest and upright in life, do things as perfectly as possible, and make products that are durable, so that they can last for a long time. Another colleague in my company has the same flashlight and a small desk lamp. The lead-acid batteries are no longer working. One of the flashlights has been used up due to incorrect methods. (All the lights are burned out) I can't control others, but I have changed all similar things to lithium batteries. This content is created by ddllxxrr, a netizen of EEWORLD forum. If you want to reprint or use it for commercial purposes, you must obtain the author's consent and indicate the source

赵玉田

This is a really good idea.

shihuntaotie

LED 18650 flashlight is OK

ddllxxrr

shihuntaotie posted on 2017-11-8 18:18 Isn’t LED 18650 flashlight OK?

That one will definitely work, but what should I do with this one? Throw it away? ? ? ?

shihuntaotie

ddllxxrr posted on 2017-11-8 20:39 That one will definitely work, but what should I do with this one? Throw it away? ? ? ?

I think it’s better to throw away this kind of flashlight. It’s of very poor quality.

ddllxxrr

shihuntaotie posted on 2017-11-8 21:50 I think it’s better to throw away this kind of flashlight. The quality is very poor

Think about it this way. If this kind of flashlight is sold to foreigners through the Belt and Road Initiative, what will foreigners think? ? ? Will they criticize it first and then throw it away, or throw it away first and then criticize it? ? ? ?

飞扬自我

The danger level is extremely high when charging. The charging voltage, current and curve of the two batteries are different. Simply replacing the battery cells is a time bomb.

ddllxxrr

Feiyang self-published on 2017-11-9 14:23 The danger level is very high when charging. The charging voltage, current and curve of the two batteries are different. Simply replacing the battery cell is a time bomb. ...

When I replaced it, I measured the charging voltage, which was about 4V, while my battery is 3.7V. It is normal for the charging voltage to be slightly higher. In addition, my lithium battery has a charging protection chip. The lithium battery power supply is 3.7V, and the charging curve is my current charging curve. There is a protection chip to prevent overcharging. What is the danger? ? ?

飞扬自我

ddllxxrr posted on 2017-11-9 15:02 When I changed it, I measured the charging voltage and it was about 4V, while my battery is 3.7V. It is normal for the charging voltage to be slightly higher. In addition, my lithium battery has a charging protection chip...

We also have several industrial lithium batteries, which are used in cleaning vehicles for industrial equipment. They also have protection boards. If the voltage is too high, they will overcharge, leak and become scrapped. There was also a gas leak, but fortunately it did not explode...

ddllxxrr

Feiyang self-published on 2017-11-9 15:33 We also have several industrial lithium batteries, used in cleaning vehicles for industrial equipment, and also have protection boards. If the voltage is too high, it will overcharge, leak and become scrapped. There is also one...

I don't know how you did it, it should be because of the high industrial requirements. I also modified a small light in my unit, LED, and it works well now

我不懂

The charging method of this type of battery is different from that of lithium batteries. It is okay for temporary use, but it is not recommended to replace only the battery for a long time, unless the charging board is replaced at the same time. This is the only way to ensure safety. After all, safety comes first.

ddllxxrr

I don't understand. Posted on 2017-11-20 09:30 This type of battery is charged differently from lithium batteries. It's OK for temporary use, but for long-term use, it's not recommended to just replace the battery, unless you're replacing the battery at the same time...

Well, I accept the suggestion. I'll buy a charging board someday.