Wednesday, April 27, 2016

Fried Batteries

We have been nursing our boats House Batteries for the past year, but they have finally given up the ghost. They are boiling off electrolyte faster than we can add it! Just a week after a top up, they drank another 2 gallons of distilled water! So, time to bite the bullet.

Searching around the web and researching the quality of batteries to use, I figured on a budget of $150 for each of the 4 6v Golf Cart Batteries. I found some at Sam's Club but not available in Florida, but at just over half price I considered having them ready for pickup out of state and making a weekend trip somewhere - it would save $300. But that didn't fly.

Then, when leaving the local Home Depot, I stopped at Batteries Plus just to inquire about their offers. They had batteries that met all my required specs for $85 each (plus tax, disposal fees etc.) So I picked up 4 of them on the spot with the caveat that if they did not fit then l could return them. (Didn't think I could measure the old ones in situ.)

Next step is to remove the old batteries and clean up the Battery Bay.

1st Battery is Out!

Here's the 1st battery out. That hole is in the cabin seat base. The previous owner had cut that out so I guess he had replaced the batteries after adding the seats.
Note the corrosion muck on the top of the battery. Not visible from the top is the fact that the sides of the battery were a bit bowed, swollen from the pressure inside during charging.

I didn't take pics of the various braces that I had to remove to get the battery out. One thing is certain, the batteries cannot move around when braced in place, and if the boat was thrown into a nasty orientation, then knowing the batteries would remain in place is a good thing. But I have no intention of every testing it out.

3 More to go!

Getting the 1st battery out was the hard part, the other three are just a case of connect the lifting strap and haul up. I figure the batteries weigh about 55lbs each. So moving them from the boat to the truck is a careful process. Don't want to slip either on the boat or between the boat and dock, especially as there is an $18 core charge on each battery that is refundable when I return them to Batteries Plus.

Battery Bay Cleanup

With all the batteries out of the boat (ok, the starting battery is not being replaced, that's pretty new). Time to clean up the Battery Bay.
The base is shaped to receive the original 2 12v Batteries, but the 4 6v Golf Cart Batteries has a higher power density as well as the fact that they nearly fill the entire battery bay. It's a tight fit.

Clean up - Done

I didn't expect it to clean up this easily nor this well. The atharwtships braces have been cleaned and the corrosion residues polished off.
The base is covered with a piece of plywood, it's stained but not damaged so just dried out and cleaned up before putting it back in place.

Time to take the dead Batteries home.

Shiny new Batteries

Got them in place, but not connected yet. Short trip to the boat today to load the batteries and do some clean up. 
These Durecell Batteries weigh in at 65lbs each and that 10lbs is a good extra chunk of lead, so I'm hoping they'll last.

Of course, maintaining and not abusing the Batteries is the way to extend their life, so the boat's electrical system is getting a bit of an upgrade too.

Part of that upgrade is to ensure all of the terminals are strong, clean and properly labeled. The labeling is part of my on going efforts to improve the quality of the electrical system and make it easier to work on the system when needed. So all of the Battery terminals have been cleaned and are ready to be labelled before reconnecting the Batteries to the boat system.

Electrical Upgrade

The upgrade consists of several steps, 1st is to construct an accurate wiring diagram that reflects the true wiring setup on the boat at present, it will actually be two diagrams. One a schematic showing what's connected to what and the other a physical diagram showing where the parts are and where they are connected. It's going to be a busy weekend.

Already determined is that there is no Galvanic Isolator installed on the boat. This could give cause to galvanic corrosion of metal parts in or surrounded by water. That includes the Prop, Shaft, Cutlass Bearing, Metal Through Hulls as well as Engine parts that are subject to salt water (like the heat exchanger) - A Galvanic Isolator is on it's way.

Second issue is the means of charging the two sets of batteries - #1 - House Batteries (that's the four that are being replaced right now) and #2 - Starting or Emergency Battery (that's a 12v battery that appears to be in good shape and holds it's charge pretty good)

To prevent the batteries from discharging to each other when not charging, I'm installing an Automatic Charge Relay (ACR) that will automatically connect the 2 battery banks when a charging current is apparent and disconnect them at other times. It also disconnects the two banks when the Starting Battery is being used to start the engine, this prevents voltage spikes being delivered to the boat's electronics.

Installing the GI is pretty straight forward, just cut the earth/ground wire from the shore power connection inside the boat, strip off the ends and connect them to the GI mounting the GI in a dry location. Should take about an hour to do that.

Installing the ACR is a little more complex, as it also requires the wiring to the two battery banks and the charging circuits. That demands that the wiring diagram is done first. So that's high up on the list. it will be a busy weekend!

And it looks like the Weekend will start early, Dan the diver is available to clean the boat below the waterline tomorrow at 10am. So I'll get an early start on the diagramming.

See you on the water.

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