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The Blue Sea Systems BS9003E Battery Switch is a high-performance, durable on/off switch designed for demanding petrol and diesel engines. Rated for 350 amps continuous current, it features one-piece tinned copper terminals for reliable, corrosion-resistant connections. Its AFD models enable safe switching under load without harming your alternator, making it the trusted choice for professional-grade marine and automotive power management.


| ASIN | B000MMC914 |
| Batteries Required? | No |
| Batteries included? | No |
| Best Sellers Rank | 101,442 in Automotive ( See Top 100 in Automotive ) 7 in Boat Battery Switches 292 in Car Battery Switches |
| Colour | Multi-coloured |
| Customer Reviews | 4.7 4.7 out of 5 stars (661) |
| Date First Available | 1 Oct. 2001 |
| Included components | Components included in the description |
| Item Package Quantity | 1 |
| Item Weight | 590 g |
| Item model number | 9003E-BSS |
| Manufacturer | Blue Sea Systems |
| Number of Pieces | 5 |
| Part number | 9003e |
| Pattern | Switch |
| Product Dimensions | 7.37 x 16.21 x 21.92 cm; 590 g |
| Size | No Size |
| Style | On-off |
| Switch Type | 1-way |
| Voltage | 48 Volts |
| Wattage | 16800 watts |
O**O
Buy this, not the cheap Chinese switches. Safety is worth the price.
Bought this for our self built camper to replace one of the cheap power switches that are all too common on Amazon. The old one was getting extremely hot even though it was operating well below its rates current, hot enough that what alerted us to it was the smell, it had only been installed for a couple of days. You get what you pay for, the quality of this switch is great, handles higher currents than the last one without even getting warm. I'm confident this one is actually rated for the current it states. Easy to install, works great. The old one was dangerous. Don't buy the the cheap Chinese ones, they're dangerous & a false economy. Spend the money, buy one of these. It's not worth the risk of an electrical fire. We've been living in our van full time for a year & a half & we've never had an issue with this switch with it regularly handling 165A when running an air fryer on our 12V leisure battery.
C**Y
Best battery switch for your boat with big engines
Very well made and easy to fit and sturdy when in place and reassuring to use compared to the usual red key switches normally fitted
Trustpilot
2 days ago
1 month ago