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Battery Charger And Isolator

Recently a reader sent in the photo above that was taken on board their boat. The question is that the electrical terminals connected to the blue colored battery isolator and several auxiliary studs don’t have any rubber boots covering them. Basically the connections you see are all live and connected directly to the battery you can see at the bottom of the photo. This collection of terminals is inside a locker that contains the battery charger (yellow and white case) and the diode type battery isolator, as well as what looks like two batteries.

The ABYC is quite clear on this in its E-11 Standard. Regarding shore power, generator or inverter supplied AC power, all termination points must be made in some form of enclosure that requires the use of hand tools to gain access. With battery level voltages under 50 volts DC, boots or covers are required for all terminals that are not protected at the source of power by a fuse or circuit breaker.

So, in looking at our reader’s photo I can’t really see a fuse or circuit breaker in the picture so I can’t be sure if all is compliant. I’m thinking though that we are looking at the engine starter battery(s) on the particular boat in question, the one exception to requiring over-current protection at the source of power, so a fuse may not be present. With that said, boots would be required on all of those terminals based on ABYC E-11 Standard.

My personal take? I want to see boots on those terminals regardless of what the nuances within the standards may say. I simply don’t want to create any risk of a spark arc that close to a battery that might just be emitting a bit of highly explosive hydrogen gas while being over-charged due to a faulty voltage regulator, improperly calibrated battery charger or connection to a solar panel with no charge controller in place, all fairly common occurrences. Boots for me please.

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