feat: add simplified battery model

Author: lymichelle21

examples/03_Existing Models.ipynb

@@ -28,6 +28,7 @@
     "    * [BatteryElectroChemEOD](#BatteryElectroChemEOD)\n",
     "    * [BatteryElectroChemEOL](#BatteryElectroChemEOL)\n",
     "    * [Combined BatteryElectroChem (BatteryElectroChemEODEOL)](#Combined-BatteryElectroChem-(BatteryElectroChemEODEOL))\n",
+    "    * [Simplified Battery](#Simplified-Battery)\n",
     "* [Centrifugal Pump Model](#Centrifugal-Pump-Model)\n",
     "* [Electric Powertrain Models](#Electric-Powertrain-Models)\n",
     "* [Pneumatic Valve Model](#Pneumatic-Valve-Model)\n",
@@ -45,7 +46,9 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "In the following battery models, the default model parameters included are for Li-ion batteries, specifically 18650-type cells. Experimental discharge curves for these cells can be downloaded from the Prognostics Center of Excellence [Data Repository](https://ti.arc.nasa.gov/tech/dash/groups/pcoe/prognostic-data-repository)."
+    "We will start by introducing the battery models: `BatteryCircuit`, `BatteryElectroChemEOD`, `BatteryElectroChemEOL`, combined `BatteryElectroChem` (`BatteryElectroChemEODEOL`), and `SimplifiedBattery`.\n",
+    "\n",
+    "In the following battery models, with the exception of `SimplifiedBattery`, the default model parameters included are for Li-ion batteries, specifically 18650-type cells. Experimental discharge curves for these cells can be downloaded from the Prognostics Center of Excellence [Data Repository](https://ti.arc.nasa.gov/tech/dash/groups/pcoe/prognostic-data-repository)."
    ]
   },
   {
@@ -452,7 +455,6 @@
     "    'save_freq': 1000,\n",
     "    'dt': 2,\n",
     "    'events': 'InsufficientCapacity',\n",
-    "    'print': True\n",
     "}\n",
     "\n",
     "def future_loading(t, x=None):\n",
@@ -535,6 +537,57 @@
     "fig = simulated_results.event_states.plot(xlabel='time (s)', ylabel='event states', labels={'EOD', 'InsufficientCapacity'})"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Simplified Battery"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "`SimplifiedBattery` is a model from [[Sierra 2019]](https://www.sciencedirect.com/science/article/abs/pii/S0951832018301406). It was initially introduced in the __[2024 PHM Tutorial](2024PHMTutorial.ipynb)__. Unlike the previous models, the default parameters are for a Tattu battery. Let's start by importing the model, initializing an instance, and examining it."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from progpy.models import SimplifiedBattery\n",
+    "\n",
+    "batt = SimplifiedBattery()\n",
+    "\n",
+    "print('inputs:', batt.inputs)\n",
+    "print('outputs:', batt.outputs)\n",
+    "print('event(s): ', batt.events)\n",
+    "print('states:', batt.states)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "We will now define future loading based on a piecewise function and simulate to a set time."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "future_loading = Piecewise(\n",
+    "    dict,\n",
+    "    [600, 900, 1800, 3000, float('inf')],\n",
+    "    {'P': [25, 12, 50, 25, 33]})\n",
+    "\n",
+    "result = batt.simulate_to(200, future_loading, {'v': 4.183})"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},