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) and two builds — the standard BG and the fully 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 BGW-40 is now the only 40A option we carry
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 | |||
|
BG-60
Best Value 60A
|
60A | 65A | 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 is there no standard BG-40?
Samlex discontinued the original BG-40 and replaced it with the waterproof BGW-40 — it’s the only 40A option currently available.
Bottom line
All five 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, then choose standard or waterproof based on where it’s mounted: dry interior compartment favors the BG-60 or BG-200, while any exposed or damp location calls for the BGW-40, BGW-60, or BGW-200.
