Well, here it is the 26th of April and no batteries yet. In some ways this has been a good thing. I’ve been able to spend quality time rehabbing the electrical system and installing the new equipment. I took my time, powering up after each major change.

It's amazing how much I've removed.

Now it's a waiting game.

​Next Up: Some FAQ's

For our battery replacement project some components will be added to support the lithium battery chemistry and some things will be removed that won’t be needed.

Here is a list of the components I’ve ordered.

100Ah LiFePO4 cells
12 cells will be wired into a 300Ah 12V configuration.

120A BMS
The BMS (battery management system) monitors and protects the lithium battery bank.

30A DC to DC charger
This is an important device. It protects the alternator, isolates the start batteries from the house battery, and charges the lithium battery bank.

25A AC to DC charger
This is a fully encapsulated and silent shore charger that replaces a VERY noisy one. It will charge the lithium battery bank.

280A Fused distribution block
A little expensive but you can’t beat the compact design.

I’ve received everything but the batteries. I’m hoping those will arrive in the next several weeks so I can finish the project before we head off the dock for the summer.

Next up: The devil is in the details.

We are in a unique period of history where nearly all things are possible if you apply enough energy. We can travel to the moon, make fresh water out of salt water, and live in the most extreme climates. As cruisers, our desires aren’t so grandiose. We just want enough energy to stay on anchor for as long as we wish without running a generator.

When we purchased Odyssey I was very excited about the three large AGM (Advanced Glass Matt) marine batteries (380 Ah total) that had been installed for the house bank. With 190 Ah of useable energy (You should only discharge an AGM down to 50% of rated capacity) I dreamt of weeks on anchor, basking in all the electricity I could ever want. This has worked well for us.

But now our AGM batteries are failing so I’ve decided to replace them with Lithium Iron Phosphate (LiFePO4) batteries.

Why lithium?

• Lithium batteries are safe. (No matter what you have been told, they don’t catch fire and melt down like Chernobyl.) (At least, not anymore.)
• Lithium batteries have a much higher energy density. That means lots of power in a small, light package, at approximately 1/6th the weight and size of an equivalent AGM.
• Lithium batteries last a long time. Most are rated for ~5000 charge cycles. That's about 10 times greater than an AGM.

So over the life of the battery, lithiums cost a lot less (per Ah) than an AGM. You can save even more if you build the lithium battery pack yourself, which is what I’m going to do.