[Amel Yacht Owners] Re: Batteries
Bill,toggle quoted messageShow quoted text
I will really be looking forward to hearing how your Firefly batteries work out for you.
I am hearing that considerably more efficient solar panels ( +30%) could become available in the not too distant future and am really hoping that happens before I put up my arch. These are the multilayered designs similar to the ones used for satellites but hopefully we be a lot less expensive or it won’t matter much if they become available or not. This technology combined with Lithium batteries would be a real game changer. I unfortunately agree with you that the Lithium Marine batteries are not quite to the point that I would want to put them in my boat for extended cruising at this time either. One significant advantage of the Lithiums that has not been mentioned is the fact that they can have a very low self discharge rate so you can get back more of what you put into the battery. The energy density is much higher than the other options that I am aware of.
As for myself, I shipped two used German 8D Prevailer Gels over to Italy for Sueno and plan to add one more new one before bringing the boat back to Florida. These batteries are amazingly reliable and long lasting..these are in fact now 16 years old and still seem to have between 90-95% of the rated capacity remaining based on a deep discharge/recharge test that I did before committing to shipping the batteries. The batteries were used hard for about 7 years, removed from a boat and then have just been recharged every one to two years so they have not seen continuous usage. The self discharge rate is very low so even after sitting for 2 years I would read between 12.5-12.6V before recharging. One downside is that the energy density is lower than the other battery chemistries so for the same number of stored amps you need more batteries/weight. On the other hand, you can cycle these batteries deeper than a flooded cell so the difference between these gels and the flooded in capacity is not as large as it initially appears to be but it is still there. They also don’t suffer like a flooded battery if you don’t fully recharge them so unless I am dockside, I don’t bother trying to bring them all of the way up. One of the best features IMO is the extremely low/no gassing. They are in fact marked safe for air transport. Interestingly, the float on both the original battery charger and the alternators on my Maramu were already below 14 volts so I did not need make any changes to the charging system install these batteries. It will be interesting to see how much longer these will last. I have had a number of the Domestic Prevailers fail at around 10 years of age or less but I have not yet had one of the German ones fail so far. Fort Lauderdale battery says that they have quite a few that are well over 20 years now that are still good. Best of luck with the Fireflies, they sound very promising!
SV Sueno, Maramu #220