今天的太阳能充电器被设计成给家用设备和车辆电池充电，例如汽车、船、房车等等。目标是有一个可靠的、免维护的、没有移动部件或不需要加油的电源。太阳能提供了答案，这就是为什么几乎所有的现代卫星都是太阳能驱动的。

事实证明，太阳能提供了一系列的好处，这些好处可以用四个简单易懂的陈述来概括。1.它干净、安静、易用、安全。2.提供电气独立性(离网)，3.最大限度地延长电池寿命。4.维护成本低且可靠。瑞萨的智能太阳能电池充电器解决方案(图1)是一个完全实现的设计，在一个紧凑的系统中涵盖了所有这些优势。

图1:智能太阳能电池充电器解决方案

系统优势：
-MPPT算法最大化太阳能电池板的电力利用率
-降压-升压架构即使太阳能电池板的电压低于电池电压,也能为电池充电
-可编程充电速率,支持快速充电和涓流充电等多种模式
-输入电压可达60V，可调节输出电压范围为0.8V至60V
-监控电池状态并保护电池免受过度充电造成的损坏

这个解决方案的核心是Renesas瑞萨晶振RL78/G23低功耗MCU (41uA/MHz)允许以低功耗运行MPPT算法，以最大限度地利用太阳能。该解决方案还支持可编程充电速率，以支持各种模式，如快速充电和涓流充电，从而延长电池寿命。这RL78/G23group拥有业界领先的最低功耗，停止时功耗为210 na(4KB SRAM保持能力)，还有一个贪睡模式序列器，可显著降低间歇操作期间的功耗。

在动力方面，DC/DC巴克RAA211820，降压/升压控制器ISL81601和RJK1003DPPMOSFETs允许我们使用最高60V的电压输入和0.8V至60V的可调输出电压，同时还允许系统监控电池状态，防止电池因过度充电而损坏。这种架构的关键是降压升压架构，即使太阳能电池板的电压低于电池电压，该架构也支持电池充电。

使用太阳能的绿色能源为电池充电是一个非常受欢迎的应用。然而,由于输出电压的广泛变化取决于指向面板的太阳能量、温度和面板上的负载,太阳能电池会产生挑战。瑞萨的这一成功组合只是在没有交流电源的偏远地区充电的一个应用。

Solar chargers today are designed to charge home device and vehicle batteries such as cars, boats, RVs, and more. The goal is to have a power source that is reliable, maintenance free, and with no moving parts or need for refueling. Solar power provides the answer, which is why almost all modern satellites are solar powered.

Solar has proven to provide a host of benefits that fit into four easy to understand statements. 1. It's clean, quiet, easy to use, and safe, 2. Provides electrical independence (off grid), 3. maximizes battery life, and 4. Is low maintenance and reliable. The Smart Solar Battery Charger solution (Figure 1) from Renesas is a fully realized design that covers all these benefits in a compact system.

At the heart of this solution is the Renesas RL78/G23 low power MCU (41uA/MHz) allowing for plenty of processing power at low power to run the MPPT algorithm to maximize power usage from the solar power. This solution also allows for programmable charge rates to support various modes such as fast-charge and trickle-charge to extend battery life. The RL78/G23 group has the industry’s leading lowest power consumption with 210nA at stop (4KB SRAM retention), and a snooze mode sequencer which significantly reduces power consumption during intermittent operation.

On the power side the DC/DC Buck RAA211820, the buck/boost controller ISL81601 and RJK1003DPP MOSFETs allow us to use voltage inputs of up to 60V and adjustable output voltages of 0.8V to 60V while also allowing the system to monitor the battery status and protecting it from damage due to over-charging. Key to this architecture is the buck-boost architecture which supports the battery being charged even when the solar panel's voltage is below the battery voltage.