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  • Writer's pictureEthan Barr

Lithium Batteries

Updated: Jun 10

A Sailor’s Perspective


The time has finally come… I’ve been waiting to write this for a while. Lithium batteries have come a long way, and so has the variety in brands and quality. Warning… it might get a bit technical 😊.


As a sailor and overlander for the past 30 years, I’ve always had to manage my power consumption carefully. Ensuring lights aren’t left on, using faucets sparingly to prevent battery drain and making sure batteries are full before sunset for night navigation lights to last through the night.


But things are changing, More and more, my customers are asking me why should they worry about power consumption when they can just upgrade to a lithium batteries. They say, “Let’s replace our current battery bank with lithium, add some charging sources, and stop worrying about power intake."


And they’re right; it’s now possible. Thanks to developments like LED lights, LED TVs, NMEA 2k networks, solid-state radars, fixed satellite antennas, and multifunction displays (MFDs) that consolidate information from multiple sources, our usual power consumption has decreased significantly.


Advancements in charging sources have also made a big difference. Smart DC/DC chargers, high-output alternators, solar power, charge controllers, brushless motors in wind vanes, and more…

It now means we don’t need to be as cautious about power consumption.

add a high-density, low-profile lithium battery with 80% depth of discharge (DOC) that offers 10 times the lifespan of a conventional battery, and it’s a no-brainer.


Let’s geek out for a second. A typical group 27 Flooded/AGM/Gel battery usually has a capacity of 105 Ah (amp-hours). If you discharge it by 50%, you significantly reduce its lifespan which is usually only 350-500 cycles.

So…to make it last longer, you only discharge it to 45-50% DOC. are now can only use 52.5 Ah of the 105 Ah.


Forget it, replace it with a lithium (specifically LFP or LiFePO4), the safest chemistry battery as of today that carry the same capacity (105ah).

And now you can discharge it to 80% DOC, allowing you to use 84 Ah, and it will do that for 3,500 cycles (almost 10 years if you discharge it once a day).


Lithium batteries also rest at a higher voltage (around 13.8V, compared to 12.8V for non-lithium). They also maintain this higher voltage longer during discharge, meaning your devices will perform better taking less current and experiencing less resistance, and if that isn’t enough, they also recharge faster, and are about 60% lighter.


However… they are slightly more expensive. but, they are a better investment if you plan to keep them for more than 3.5 years. You see, Non-lithium batteries should be replaced every 3-4 years. costing you around $220-$350 each time you replace it, after 3.5 years, you’d spend $440-$700 which is what it'll cost you if you buy a lithium battery, only it will last 7-10 years, and provides 38% more usable power before needing a recharge.


Buyers beware: don’t buy the cheapest lithium battery without researching it first. There are many options out there, and they’re not all good. I only buy from trusted brands like Battle Born, Victron Energy, Epoch Batteries, Master-Volt, and Go-Power by Dometic. Each has its strengths and weaknesses, which I’ve learned through experience so Feel free to contact us if you have any questions!

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