Battery Guards Compared: BG vs BGW and Which Amp Rating You Need
Samlex battery guards protect your battery bank from over-discharge and your electronics from overvoltage. We carry them in three amp ratings (40A, 60A, 200A): the 40A and 60A guards come in the fully waterproof BGW build, and the 200A in both the standard BG and the waterproof BGW. Here's how to pick the right one.
- Standard (BG) vs waterproof (BGW): what the difference actually buys you
- 40A, 60A, or 200A — matching the guard to your load
- Same core over-discharge/overvoltage protection across the lineup
- Why the 40A and 60A guards now come only in the waterproof BGW build
Our lineup at a glance
| Continuous Load | Transient Load | Waterproof | Remote off / alarm output option | 12V/24V auto-detect | Programmable threshold voltages | ||
|---|---|---|---|---|---|---|---|
|
BGW-40
Only 40A Option
|
40A | 45A | 10 programs | BUY NOW | |||
|
BGW-60
Best 60A Waterproof
|
60A | 65A | 10 programs | BUY NOW | |||
|
BG-200
Best Value 200A
|
200A | 210A | 10 programs | BUY NOW | |||
|
BGW-200
Best 200A Waterproof
|
200A | 210A | 10 programs | BUY NOW |
Electrically, the standard and waterproof versions do the same job: they disconnect the load before your battery is damaged by over-discharge, and protect connected electronics from overvoltage. The BGW’s sealed, waterproof enclosure matters if the guard will be mounted somewhere it can get wet or humid — an engine bay, a boat’s battery compartment, an exposed enclosure box. If it’s mounting inside a dry cabinet or interior compartment, the standard BG does the same protection for less money. The BGW models also add options for a remote off switch and an alarm output (buzzer, LED strip, or relay) that the standard BG models we carry don’t list.
Do I need the waterproof (BGW) version?
Only if the guard itself will be exposed to moisture — rain, spray, high humidity, or a wet bilge/engine bay. If it’s mounted in a dry interior compartment, the standard BG saves you money for the same core protection.
How do I pick the right amp rating?
Size it to the continuous current draw of whatever it’s protecting — typically your inverter or DC load circuit. Check your inverter or appliance’s rated continuous draw and choose a guard whose continuous rating comfortably covers it; the transient rating gives you headroom for brief surges.
Why are there no standard BG-40 or BG-60 guards?
Samlex discontinued the original BG-40 and BG-60 and replaced them with the waterproof BGW-40 and BGW-60, so those are the only 40A and 60A options currently available.
Bottom line
All four guards share the same core over-discharge and overvoltage protection with 10 programmable threshold settings and automatic 12V/24V detection. Pick your amp rating to match your load, At 40A and 60A, the waterproof BGW-40 and BGW-60 are the only choices. At 200A, choose by where it’s mounted: a dry interior compartment suits the standard BG-200, while any exposed or damp location calls for the BGW-200.
