With a protection board, you can use 5V (anything between 4.8 and 5.2 is acceptable), either a computer's 5V USB port or the charger 5V from a cell phone.
Generally, 3.7V lithium batteries must have a “protection plate” against overcharging and overdischarging. If the battery does not have a protection plate, it can only use a charging voltage of around 4.2V. since the ideal full charge voltage for lithium batteries is 4.2V , the battery may be damaged if the voltage exceeds 4.2 V. When charging with this method, you must monitor the battery status at all times.
Detailed information:
Lithium battery charging knowledge:
1. Charging voltage:
General mobile. phones Battery voltage is written as 3.7V, but general charger voltage is writtenlike 5V, but it won't affect the usage because there are no 3.7V cell phone chargers for sale. No. 5 cylindrical lithium battery, that is, 14500 battery. It uses lithium battery voltage regulator technology to adjust the battery voltage to 3.0V suitable for small devices electrical.
2. Long-term charging and deep charging:
Long-term charging may result in overcharging. Lithium batteries or chargers automatically shut off once the battery is fully charged. There is no so-called “maintenance” charge that lasts more than 10 hours with nickel battery chargers.
3. Overcharge and overdischarge:
The rated voltage of lithium-ion batteries, due to material changes, is generally 3.7V, and the positive electrode is lithium iron phosphate. (hereinafter referred to as iron phosphate) is 3.2 V. The international standard forTermination charging voltage when fully charged is 4.2V and that of iron phosphor is 3.6V.
Baidu Encyclopedia - Lithium Battery
How to change the output of a 3.7V 14500 lithium battery to 1.5V
Rechargeable lithium battery 14500 3.7V There is no one above 2500 mah.
At present, the capacity of 18650 lithium battery is generally only 2000-3000 mAh. The internal space of the 14500 rechargeable lithium battery is much smaller than that of the 18650 lithium battery, and the effective electrode material that can be accommodated is much less than that of the 18650 battery, so the capacity does not 'will not reach more than 2500 mAh though. the 14500 lithium battery sold is marked 2500mAh or more, it must be a false target.
With existing technology, the capacity of a 14,500 lithium battery can be around 1,000 mAh.
To change the outpute from a 3.7 V 14,500 lithium battery to 1.5 V, you just need to connect a resistor in series. The resistance value depends on the actual situation. Generally, Bluetooth batteries are 3.7V. Please first check whether the original lithium battery is intact.
Or connect LC9200D lithium battery charge and discharge management chip in series. When charging, the 3.7V/3.2V/2.4V lithium battery can be charged, and the current can be configured up to 0.5A. When discharging, a synchronous step-down converter with a switching frequency of 1.5 MHz is used for discharge, and the. The discharge current can reach 2A. Internally integrated undervoltage, short circuit and overtemperature protection functions. LC9200D SetIndicates charging, full and short circuit status.
Detailed information:
The following points should be pConsiderations when using lithium batteries:< /strong> p>
1. Pay attention to the “+” and “-” marks on the battery and electrical appliances, and install batteries in electrical appliances correctly. If the battery is installed upside down, it may be overcharged or short-circuited, resulting in overheating, leakage, discharge, rupture, explosion, fire and personal injury.
2. Do not short circuit the battery. When the positive (+) and negative (-) terminals of a battery are connected to each other, the battery is shorted. For example, if the battery is placed in a pocket containing keys or coins, the battery may short circuit, resulting in discharge, explosion, fire and injury.
3. Do not charge the battery. Attempting to charge a non-rechargeable battery (primary battery) will generate gas and heat inside the battery, causing aleakage, discharge, explosion, fire and injury.
4. Do not mix new and old batteries, or batteries of different models or brands. When replacing batteries, replace all batteries at the same time with new batteries of the same brand and model. When batteries of different brands and models or old and new batteries are mixed, due to differences in voltage or capacity, some batteries may be over-discharged or forced to discharge, resulting in leakage, explosion, fire and serious damage. injuries.