38. Battery Mini-Breaker for Power Tool Battery Protection
1. Component Purpose
Power tool battery packs deliver extreme currents (25A+) and generate significant internal heat during heavy drilling. A higher trip temperature (90°C) allows normal high-load operation without nuisance tripping while still providing protection.
The 5S pack (21V max) needs a breaker rated ≥28VDC. The MHP-TAT series from Littelfuse supports higher voltage and current than the TAM series.
Required: Breaker · 90°C trip · ≥28VDC · ≥30A · Active · Littelfuse · RoHS
2. How to Find It on DigiKey
Same category. Apply these filters:
- Type → Breaker
- Rated Functioning Temperature → 90°C
- Current Rating (Amps) → 30A or higher
- Manufacturer → Littelfuse Inc.
- Part Status → Active
Important: Verify voltage rating ≥28VDC in the datasheet. The 5S pack charges to 21V, and transient voltage during regenerative braking can be higher. 28V provides necessary margin.
3. Key Specifications & What They Mean
| Specification | Required | Why |
|---|---|---|
| Type | Breaker | Resettable thermal cutoff. |
| Trip Temperature | 90°C | Higher threshold for power tool heat. |
| Voltage Rating | ≥28VDC | 5S pack max = 21V; 28V gives margin. |
| Current Rating | ≥30A | 25A peak + derating margin. |
| Part Status | Active | Currently manufactured. |
| Manufacturer | Littelfuse | Company AVL. |
| 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