サブバッテリー復活　サルフェーション除去　パルス充電　バッテリーチェッカー　ディープサイクルバッテリー

The 100Ah deep-cycle battery (ACDelco M27MF) I replaced three years ago has recently started to malfunction. When solar charging stops at night, the voltage drops, causing my refrigerator to shut down. Inexpensive deep-cycle batteries begin to deteriorate internally after about 500 recharges, with a lifespan of three years. I've heard that depending on usage, it can last as little as one year, so I felt it was time to replace mine. However, there are apparently two causes of battery deterioration: physical causes such as corrosion or damage to the electrode plates, and chemical causes such as sulfation (lead sulfate crystals) that form on the electrode surface. While the former is unavoidable, I've heard that the latter can be remedied with "pulse charging." Sulfation (lead sulfate) is a non-conductive crystal formed by a chemical reaction and accounts for 70% of battery degradation. Newly formed sulfation is very soft, so immediate charging dissolves it into the electrolyte. Frequent charging reduces the loss of battery capacity. However, if the battery is left unused for a long period of time or is over-discharged during use, the sulfation gradually hardens and adheres to the surface of the electrode plates, rather than returning to the electrolyte even when the battery is charged. Sulfation, an insulator, increases internal resistance, resulting in reduced power and capacity. Pulse charging refers to a charging method that applies electrical vibrations, generally at 30-60 kHz, and in research at 1.5 MHz. Sulfation occurs when lead sulfate, a non-conductive substance that adheres to the electrode plates, crystallizes over time without breaking down. Sulfation accumulates and deteriorates, eventually reaching the end of its life. Applying electrical vibrations (pulses) during charging has been shown to promote the decomposition of sulfation. Using a pulse charger for daily maintenance can help maintain the battery's condition. At what stage of the charging process is it most effective to apply pulses? According to battery charger manufacturer Omega Pro https://www.omega-pro.jp/ The pulses apply throughout the entire charging process. Before replacing the battery, I thought I'd try pulse charging, so I bought a relatively inexpensive (¥10,998) LVYUAN pulse battery charger and a battery diagnostic device (¥3,949) (see below for links). The results are as shown in the video. It's still unclear how long the effect will last. But so far, the refrigerator has stopped working in the evening when the solar panel usually shuts off, and at dawn the red battery alarm has completely disappeared. Not only has the refrigerator run without any problems until morning. There are two points to note here. First, when measuring with the battery checker, an error occurred if the terminals were threaded. This is probably because the ground surface area becomes small and point-like, creating resistance. Second, the sub-battery, left connected to the solar panel, shows 13.2V, so even if it is degraded, it appears to be fully charged. However, if it is discharged using power from a refrigerator or other power source, the voltage drop time is short and the refrigerator will stop. Even if you apply pulse charging from this state, there will be almost no charging time and the sulfation will not be removed. Therefore, if you discharge the battery to a certain extent and then reconnect to pulse charging when it reaches around 12.2V, you will have about 24 hours of charging time, which will allow for successful desulfation. Furthermore, about two years ago, I built a circulating current prevention circuit using a Schottky barrier diode, but this also had two problems. First, the voltage drop of the diode itself causes the actual voltage to drop 0.37V lower than the battery during rectification, which causes refrigerator malfunctions. Therefore, I decided that I only needed to protect the new battery, so I limited the diode to one location in the circuit. This allowed me to ensure a wiring path from the new battery to the refrigerator without any voltage drop. Secondly, the copper wire extending from the diode is thin, and I previously connected two in parallel out of concern for heat generation. However, unlike resistors, diodes, even when connected in parallel, will always pass most of the current through one of the diodes, so I realized that connecting them in parallel was pointless. So I replaced the two parallel-connected batteries with a maximum operating current of 15A with a single 30A battery. CCA (Cold Cranking Ampere) is a performance standard that indicates the battery's ability to start an engine. It represents the maximum current (A) at which a battery can maintain a terminal voltage of 7.2V or higher after 30 seconds of constant current discharge from a 100% charge at a low temperature of -18°C ±1°C. CCA was primarily adopted in the United States, but has also come to be used in Japan. While 0°F is -17.8°C...