Let's talk about power!!!

Not so long after we arrived in Grenada we took a trip back to the states to see family. Upon returning to the boat we found our beloved house battery bank had failed. 

We had 4 flooded cell Trojan batteries. These batteries were on Calypso when we bought her, we suspected they were a little weak after using them while sailing through the islands. Flooded cell batteries need constant attention such as monitoring charging/depletion status. Most importantly is ensuring the cells don’t go dry. You have to refill them with distilled water, usually once every few weeks (more in the hot tropical climates). We believe the batteries had been allowed to get low at times before we owned the boat which reduced their life. They just weren’t too impressive. We’d run the generator twice a day to keep them up while other boats wouldn’t have to run theirs at all. 

So we watched them carefully, made sure they were full of water and did what we could to make them last. Unfortunately, the trip to the states resulted in them getting too low on water once again, that was the final straw. A test of the remaining water inside proved that our battery bank had indeed failed. There are some tricks out there to kind of nurse batteries back after a lot of time charging and messing with water but they'll be weak and a pain. We're about to cross an ocean...We had to replace the bank. 

On our boat the house batteries run everything. When hooked to a dock the power runs through the inverter and the boat will operate…Even without batteries. While off dock power though…Nothing will. The batteries run critical systems like the freezer, refrigerator, bilge pumps, etc…Everything except the air conditioners and water heaters. It’s a huge part of the living conditions and being that we live on our boat, it’s crucial. 

So we had to make a decision. We could either purchase the same type of batteries we had before for a few thousand dollars, continue the worry of checking them, filling them, charging them and so on…Or we could make the decision to purchase Lithium Iron batteries. A type of battery that’s more powerful, requires no special attention, no re-filling, no charging monitoring…Basically plug and forget batteries. The only thing is that they're about 3-4 times the cost of the flooded cell batteries. This type of battery is considered one of the ultimate upgrades you can do to a boat. 

Now, there are other battery types on the market like gel batteries and such but we didn’t consider them an option. A fair amount of other cruisers have them and the reviews are average at best. Flooded cell cruisers talk about how they wish they could upgrade while Lithium Iron cruisers rave about how amazing they are.

Another good point to Lithium Iron batteries is the life span. This type of battery will outlast the flooded cell by a long long time. If you do the math on life cycles and all that (just google it), you’ll find that it’s actually cheaper in the long run to purchase and use the Lithiums. Especially if you live aboard! Living aboard greatly increases the use of your batteries life cycles. 

So is it worth the cost for us? We live aboard full-time. I mean really full-time…We aren’t on for 6 months and off for 6 months. This is our home, I’m typing this at our saloon table in the middle of hurricane season. We aren’t leaving for a comfy house back home. This is it. So we treat the boat as we would a house in the states. So yes, to us it was worth the price to upgrade the batteries to the more powerful, easier to use Lithium Irons.

We removed the old stinky batteries and placed an order for two Reli3on RB300-HP batteries. In the meantime we borrowed a single 12 volt battery to use as a back up just in case we lost dock power for a little bit, which happens from time to time. Then we waited! It took about 4 weeks for the new batteries to be shipped here…Yes, by boat! Finally, they arrived! 

We’ve now had our two new batteries for about a week and let me tell you…They are AWESOME! I’ll try to give an example here:

With the flooded cell batteries, we’d charge the battery bank before we went to bed. When we’d remove the charger the batteries would settle to 12.5 volts (full) and then we’d go to bed. We pull about -20 amps an hour at night on Calypso. We’d wake up in the morning to the batteries being at about 11.0 volts…Drained but not dead, around 10.5 volts would be dead. Sometimes the wind generator would help if it were windy but that’s about average. 

Our new batteries, when pulled of the charger settle at about 13.6 volts (very full) and after running everything all night long (no wind generator) we wake up to a battery bank that’s sitting at 13.3 volts. It’s incredible.

Another thing to consider here is how many more amp hours we’ve upgraded to. This can get confusing but I’ll try to explain. 

First, think of an amp hour as fuel…Maybe 1 amp hour is like 1 gallon of fuel...

Our last battery bank had a total of 450 amp hours. Flooded cell batteries only allow for 50% of those to be used so we really had 225 usable amp hours. We pull about -20 amps per hour at night. 10 hours equals 200 amps so we’ve used all but 25 amps in the batteries…They’re basically almost empty. 

This Lithium Iron battery bank is a 600 amp hour bank. Now, Lithium Iron batteries allow you to use 80% instead of 50%. So we actually have 480 amps to use now instead of 225. The boat pulls the same amount, -20 amps per hour. After we use the 200 amps over night we technically should still have about 280 left! More than the flooded cells when they’re fully charged!! 

All this power and we actually went from four 100 pound batteries to just two much lighter batteries.

It does come at a cost though. Ready for this?! We had to fork out just under $7000.00 for the two batteries you see here. Yes…Seven. Thousand. Dollars….That’s just the batteries!! Not labor or anything else! Luckily we don’t have to pay for labor. Before doing this sailing full-time thing, seeing how important batteries are out here I would’ve laughed at the idea of paying so much for batteries but…These are our main power source for our home. We’re excited to move along with them, it almost feels like the boat is nuclear powered now!  

Do you have any questions about our new house bank? If so send them to us!