Battery Charger Replacement

The new boat has three 105a AGM batteries, an elaborate solar charing system, and the old Lewco Silicon Diode charger Tom mocks in this photo.

The surveyor noted that such a charger is not recommended for sealed batteries, because "it can damage them."

I have yet to dive into this rehab area, but what is the clear and present danger to my AGM batts?

Christian Williams said:

The new boat has three 105a AGM batteries, an elaborate solar charing system, and the old Lewco Silicon Diode charger Tom mocks in this photo.

The surveyor noted that such a charger is not recommended for sealed batteries, because "it can damage them."

I have yet to dive into this rehab area, but what is the clear and present danger to my AGM batts?

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I would contact LEWCO before replacing that charger - http://www.lewcoelectriccompany.com/Contact_Us.html

My old Raritan battery boiler had to be replaced, but if there is still and engineer to talk to at LEWCO they may be able to tell you for certain.

Christian Williams said:

but what is the clear and present danger to my AGM batts?

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Chargers made made for lead acid batteries charge at a higher voltage than AGM batteries will tolerate, unless The charger has a setting to adjust charging voltage. I stuck with lead acid (golf cart) so I don't really remember the particulars beyond this.

Tom Metzger said:

Peter - It is advantageous to wire permanently installed equipment to the AC panel. This gives you a dedicated circuit breaker for your charger and allows you to turn it on and off easily. Most chargers for boats your size don't come with line cords and require direct wiring.

Unless you can get into the charger to connect the AC cable directly to the charger I would splice it like the previous owner did. An alternative would be to install an outlet in a box at the end of the AC cable and plug your charger into it.

Harold - Why do you say "Do NOT splice into the 110 circuit"?

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I think he meant DO run it through the breaker panel.

I, too, cut off the plug and wired it to a breaker. I found a convenient way to do this was to hook the battery charger cable into the output terminals of a (GFI) outlet near the engine. So the battery charger circuit also includes a convenience outlet. Effectively the same as plugging the charger into the front of the outlet, but no exposed cord to trip over, work loose, strangle the guy in the Q-berth, etc. And it's much more convenient to just flip a switch on the panel than to crawl in the back and fish out that cord.

Christian Williams said:

The new boat has three 105a AGM batteries, an elaborate solar charing system, and the old Lewco Silicon Diode charger Tom mocks in this photo

Click to expand...

My good friend Tom would never mock anyone, especially when it comes to electrical engineering! :cartmann::nerd::0

My good friend Tom would never mock anyone, especially when it comes to electrical engineering! :cartmann::nerd::0

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Oh damn, I'm over here on the east side (it's where I'm invited, don'tcha know) and they have been feeding me strong drink. I'll respond in the morning if I survive.

OK, I survived. A good thing.

If I had an investment in AGM batteries I would want a smart charger to properly charge them to, hopefully, prolong their lives. The Lewco charger is many things, but smart is not one of them.

My understanding is (per Maine Sail) that most boat owners don't get the promised long lives from AGM batteries.

Disclosure: I've never had one and have no experience with them. To me, the only real advantage of AGM batteries is that they are sealed and can be placed where maintenance would be inconvenient. Oops... one other. If they were on the boat when I bought it.