37. Battery Mini-Breaker for Tablet Battery Protection
1. Component Purpose
Li-Polymer batteries can enter thermal runaway if overheated — a dangerous chain reaction where temperature rises uncontrollably, leading to fire or explosion.
A battery mini-breaker (MHP) is a resettable thermal cutoff mounted directly on the cell. When the cell temperature reaches the trip point (85°C), the breaker opens and disconnects the cell. When the temperature drops, it resets automatically — unlike a one-shot thermal fuse which must be replaced.
Required: Breaker · 85°C trip · ≥9VDC · ≥12A · Active · Littelfuse · RoHS
2. How to Find It on DigiKey
Go to DigiKey.com → Circuit Protection → Thermal Cutoffs (Thermal Fuses)
Apply these filters:
- Type → Breaker
- Rated Functioning Temperature → 85°C
- Current Rating (Amps) → 12A or higher
- Manufacturer → Littelfuse Inc.
- Part Status → Active
Tip: The Littelfuse MHP-TAM series is specifically designed for battery protection. "Breaker" type means resettable — it is NOT a one-shot thermal fuse.
3. Key Specifications & What They Mean
| Specification | Required | Why |
|---|---|---|
| Type | Breaker | Resettable; resets when temp drops. |
| Trip Temperature | 85°C | Protects before thermal runaway onset. |
| Voltage Rating | ≥9VDC | 2S pack max = 8.4V; 9V covers it. |
| Current Rating | ≥12A | Peak 8A + derating margin. |
| Part Status | Active | Must be currently manufactured. |
| Manufacturer | Littelfuse | Company AVL requirement. |
| RoHS | Yes | Compliance required. |
4. Selecting a Safe, Production-Ready Part
The filtered list will show matching parts. Before you pick one, check: Is it Active? Is stock available? Is the manufacturer reputable? Is a datasheet available?
Full checklist: How to Select a Safe, Production-Ready Component — EWskills Guide