Wednesday, October 6, 2010

Feel the Power - Batteries and self sufficiency

The goal is self sufficiency, and that means generating enough "off the grid" electricity to meet your needs. We'll it actually means curbing your needs to the power you can generate. After hundreds of hours research, scratching our heads, confusion over watts, volts and amperage,  we finally found the answer in a video clip of an old guy in the mountains. The advice he very eloquently gave is "It's much easier to use less electricity than it is to make more".

So, armed with this new found knowledge, we are adding two large solar panels to Odessa's arch because that's all we can fit without adding dangers on deck. More on solar panels next week when they should finally arrive from Miami.

But, making electricity is only half the story... storing it is the other half, you need batteries, and lots of them. Odessa has a simple "bullet proof" battery bank... six Trojan 6v batteries with lots of the "important" piece of the equation... amp hours.

When you buy an old boat, have new batteries in you refit budget... no matter what the owner or broker might say about their age, they will need to be replaced. One bad battery in the bank brings the whole bank down and you want to know and manage your whole system from fresh... or you'll be frustrated endlessly trying to trouble shoot. I really suck at electrical work, so $1,000 for new batteries is worth every penny.

We took on this project today because it is raining like mad with little breaks, so working inside Odessa seems like a good plan.

There are a huge range of batteries, from size, voltage, wet cell, glass matt, and gel. We're sticking with the old tried and true Trojan wet cell 6v batteries which are rigged to make the equivalent of 3 12v batteries with 235 amp hours each... so 705 amp hours total per charge. Trojan 6v batteries give the longest life and lowest amp hour cost... perfect for cruisers. We'd love more, but space is an issue and batteries are very very heavy... if we reduce the space needed for our old fridge compressor we may squeeze two more batteries into the space, it's all about compromise, give and take, and using new technology to save space on an old boat to be able to add new things.

We worked some deals and manage to get them for $150 each on the island which is cheaper than in the US, so we jumped on the deal and headed for the boat. It took a couple of hours to replace all six batteries... NOTE: It's best to install them while you're at the dock... hauling them up 15ft while the boat is in the yard is a pain... especially when it's raining and decks are slippery. And remember, the old ones have to come down.

Clean all terminals, clean the compartment, you'll not be back in there for a long time... hopefully.
Batteries are very reliable as long as you do some simple maintenance... check the water level every week (wet cell) keep an eye on how they charge and don't let them drop bellow 30% charge. When you replace your batteries you need to charge them and then equalize (boil) the whole battery bank to make them all work together as a team. Your battery charger (we have a Xantrex 20) will have instructions on equalizing, but essentially the charger will overcharge the bank at about 14.5v for a period of time which boils the plates and cleans off any contaminants. Remember this blog is for the new sailor so please excuse the terminology and suggestions that will seem very basic to the experienced sailor. I always remind myself that every experienced sailor was one a newbie.

I hope this simplifies the whole "oh, the batteries need replacing" realization if you buy an old boat... Doreen isn't in the pictures, but she was essential when it comes to lugging batteries around, they are surprisingly heavy and cumbersome... we're off to Odessa now to get the old ones off the boat... nice.

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