Charging and discharging batteries is a chemical reaction, but it's claimed that Li-ion is an exception. Li-ion batteries are influenced by numerous features such as over-voltage, undervoltage, overcharge and discharge current, thermal runaway, and cell voltage imbalance. One of the most significant factors is cell imbalance which varies each cell voltage in the battery pack overtime and hence decreases battery capacity rapidly.
How to charge ECO-WORTHY lithium battery?
You can charge your lithium iron phosphate batteries whenever you want just like your cellphone. Unlike lead-acid batteries, lithium iron phosphate batteries do not get damaged if they are left in a partial state of charge, so you don’t have to stress about getting them charged immediately after use. They also don’t have a memory effect, so you don’t have to drain them completely before charging.
There are two methods for battery charging:
1. battery charger（mains power）
2. solar panel (DC power)
The most ideal way to charge a LiFePO4 battery is with a lithium iron phosphate battery charger, as it will be programmed with the appropriate voltage limits. Most lead-acid battery chargers will do the job just fine.
AGM and GEL charge profiles typically fall within the voltage limits of a lithium iron phosphate battery. Wet lead-acid battery chargers tend to have a higher voltage limit, which may cause the Battery Management System (BMS) to go into protection mode. This won’t harm the battery; however, it may cause fault codes on the charger display.
Li-ion Battery cell level and pack level control variables are needed to be maintained accurately for safe operation. These control variables are monitored and protected by the battery management system (BMS).
BMS is an electronic device that acts as a brain of a battery pack, monitors the output, and protects the battery from critical damages. This incorporates monitoring of temperature, voltage and current, failure forecast or prevention, and data collection through communication protocol for battery parameter analysis. Battery state of charge (SOC) is the percentage of energy currently stored in the battery to the battery nominal capacity. One of the important key functions of BMS is the cell balancing.
Of course, you can also use solar panel to charge your ECO WORTHY LiFePO4 battery, but please make sure to choose a proper controller, both PWM controller and MPPT controller are okay.
And as an SLA targeted 12V panel makes about 18V at full-sun full-load, such a 12v panel will provide more than enough voltage under all practical light conditions.
If you don't have a controller, you can connect the battery to the solar panel, too. The BMS inside will protect the battery in most times.
But if there is a defect on the battery BMS, the battery will be damaged.
The ECO WORTHY Battery Management System (BMS) performs three primary functions:
1. It protects the battery pack from being over-charged (cell voltages going too high) or over-discharged (cell voltages going too low) thereby extending the life of the battery pack. It does this by constantly monitoring every cell in the battery pack and calculating exactly how much current can safely go in (source, charge) and come out (load, discharge) of the battery pack without damaging it. These calculated current limits are then sent to the source (typically a battery charger) and load (motor controller, power inverter, etc), which are responsible for respecting these limits.
2. It calculates the State of Charge (the amount of energy remaining in the battery) by tracking how much energy goes in and out of the battery pack and by monitoring cell voltages. This value can be thought of as a fuel gauge indicating how much battery power is left in the pack.
3. It monitors the health and safety of the battery pack by constantly checking for shorts, loose connections, breakdowns in wire insulation, and weak or defective battery cells that need to be replaced.
Unless you like living on the edge, DO NOT BUY a battery without BMS!
How to choose ECO WORTHY lithium battery charger? Can I charge my lithium battery with a lead acid charger?
Lithium batteries are not like lead acid and not all battery chargers are the same. A 12v lithium battery fully charged to 100% will hold voltage around 13.3-13.4v. Its lead acid cousin will be approx 12.6-12.7v.
A lithium battery at 20% capacity will hold voltage around 13V, its lead acid cousin will be approx 11.8v at the same capacity.
So if you use lead acid charger to charge your lithium battery, it may not be fully charged.
You can use a AC to DC lead acid charger powered from mains power, as charge efficiency and duration are less of a concern, it must not have automatic desulphation or equalization modes. If it does, do not use it as there is a high chance of damage to the cells or battery. This can have significant reduction in battery longevity. If it has a simple bulk/ absorption/ float charge profile, then it can be used to recharge the battery but must be disconnected once charged and not left in trickle charge/maintenance mode. It must also have a maximum output voltage of 13v-14.5V. When it comes to DC- DC chargers and solar controllers, you must change these to LiFePO4 specific models.
Our ECO WORTHY battery charging parameters consist of the following:
✹Bulk/absorb: 14.2V- 14.6V. ✹Float: 14.6v ✹Equalization: 13.6v- 14.0v
But it would be the best for you to choose a specific lithium battery charger. There are many brands on the Internet for you to compare: REDARC, Enerdrive, Victron, Projecta, Intervolt and so on. We made an investigation on Victron’s IP-65 Blue Smart Charger, it’s waterproof, Bluetooth compatible, and has a charging profile for lithium batteries and other battery chemistries.
This device connects directly to the battery and is meant for single-battery charging. It’s great for those with trolling motor applications or those with battery systems connected in series.
Can I charge lithium batteries in the cold?
Lithium batteries rely on chemical reactions to work, and the cold can slow and even stop those reactions from occurring. Unfortunately, charging them in low temperatures is not as effective as doing so under normal weather conditions because the ions that provide the charge do not move properly in the cold weather. There's one hard and fast rule: to prevent irreversible damage to the battery, don't charge them when the temperature falls below freezing (0°C or 32°F) without reducing the charge current. Because the lithium batteries suffer from a phenomenon of lithium metal plating on the anode if charged at high rates in cold temperatures. This could cause an internal short of the battery and a failure.
Please look at the following table to see the relationship between the voltage and temperature.
Can I leave ECO WORTHY lithium battery on charging all the time?
For a lithium battery with a low maintenance charging procedure and battery management system, it's perfectly fine and better than leaving them discharged for a long period. Regardless of whether it is a dedicated charger or a general charger, under normal conditions, it has a charging cut-off voltage, which means that it will stop charging at a certain volt. The same is true for the solar panel controller, and the controller can also be configured like this. The solar panel is directly connected for charging. If there is a problem with the BMS, it may be overcharged.
Can I recharge my lithium battery from my vehicle alternator?
Yes, but not necessarily to full charge, due to the fact that most Alternators are adjusted for the lower voltage requirements of the vehicle Lead/Acid Battery (approximately 13.9-v). Lithium Batteries require 14.4 to 14.6-Volts to fully charge. That being said, you can get up to approximately a 70% charge, depending on the depth of discharge and distance driven while recharging from your vehicle alternator.