Batteries

As promised, I wanted to let everyone know about my new house battery.  Notice the singular?  We have removed nearly 300 lbs of 2 group D AGM batteries, totaling 850 amp hours and replaced them with a single Valence Lithium Phosphate battery, Group 27 size, 138 Amp hour and weighing only 41 lbs.  That is 250 pounds of weight out of the port hull and no battery in the engine compartment anymore.  That hull has lifted up nearly an inch out of the water.

We did this for two reasons.  One was the existing batteries were shot and needed to be replaced.  Second is the ever demanding need to reduce weight and keep Yasmine Ann sailing fast.  We have noticed a half a knot of reduced speed when our 100 gallon water tank is full.  It is located forward of the cabin house, so it digs the bows in.  We already removed 1 spare anchor from that location as well.

The Valence battery has been around for about 7 years now.  It is the only chemistry that can use the same charging systems as your lead acid based batteries and does not have the exploding problems of the other lithium configurations.  I researched them when I was looking at replacing the engine batteries in Yumsuch.  Back then, they were too expensive.  Now they are close to the cost of a large AGM bank, by someone good like Lifeline.  The difference is a 15-20 years life expectancy, versus 3-5 years.  So, if all works as stated, it will far outweigh the original cost.

After 1 month of running the battery, there are some very positive reports.

1.  The voltage has never dipped below 13.2V.  This is with up to 60 Amp hours down and loaded up to 10 amps.  This does a couple of things.  The refrigeration compressors run better and less time.  Both the refrigerator and freezer have never been colder.  Even the water pump and macerater toilets work better.  We are using less water to flush with the renewed power on the heads.  

2.  The battery recharges faster.  With a lead acid chemistry, the internal resistance increases as you get closer to your acceptance voltage.  This reduces the amount of current the battery can take.  That is why, when you are charging with solar and wind, it takes forever to get to float, if you make it at all.  With the Valence battery, it takes the full current right up to the acceptance voltage of 14.6V.  Then it drops to float.  One of the biggest problems with the AGM, and this is stated in the Lifeline datasheet, is that if you do not reach full charge at the end of each charging cycle you shorten the life of the battery and Lifeline will not warranty it.  With the battery management module, used with the Valence battery, you only have to reach full charge once per week for it to properly balance the cells within the battery.

I know I am going on too long.  Some of you like to hear these details.  But, I will quit for now.  If you have any questions, feel free to contact me.  I can get you in touch with my contact at Valence.

We just spent the last week anchored in Miami and are now back in Marathon.  We went for the boat show and learned a lot about new products and old ones we have been researching.

 The new green Valence battery in comparison to just one of the AGM batteries removed.

 Close-hauled at 50 degrees apparent on our way to Miami, all under code 0 and mainsail.

Sunset, downwind sailing at 160 degrees with code 0 only on the way back from Miami.  We sailed all code 0 to and from Miami.  Thank you Haarstick Sails!