Re: Batteries

amelliahona <no_reply@...>

Hi Graham:

Heat and usage, along with the type of usage, and the type of batteries is what eventually leads to their demise.  There are only so many charge-discharge cycles stored in a battery and the more of those cycles used over a give time frame will hasten their "consumption".  Proper charging and battery maintenance also impact batteries and varies depending on the type of battery.  I think that if you had good service for 2.5 years in hot conditions with frequent use of flooded lead acid batteries such as your Trojans, that is about all you can expect.  Frequent charging, minimal discharging, careful maintenance etc will yield greater longevity.  I have Trojans aboard my boat and I find that it is a constant battle to keep the water levels topped up in the heat of the Caribbean. I think the Trojans battery cap design is not the best.  I have to add significant amounts of distilled water every month.  When I leave the boat on the hard, I have solar panels trickle charge them, but still have the caretaker plug the boat in for 6 hours one a month for a better top-up and also service the water level every month.  I only use the boat for about 3 months a year, and with this regimen I get about 4 years from a set of batteries.  Sad but true, the heat, the cycling, the motion etc, all take their toll.


Gary Silver

s/v Liahona 

Amel SM Hull # 335

On the hard in Antigua 

---In amelyachtowners@..., <richard03801@...> wrote:

Hi have you had the batteries load tested?  
When you say the boat is in use, what is the major method of charge the motor or gen set. 
The alternators on the motor will most likely not top off the charge. (Note the number of over 50% discharges have a lot to do with battery life as does the quality of water used to refill them) 
The gen set by way of a smart charger will top off the batteries then "float" charge. (Given you are in HK it is also important you don't over heat the battery bank. Most new smart chargers have a temp sensor that sits on top along side the batteries. 
Go luck keeps up to date.

Richard Piller 
Fairbanks Yacht Group llc
Support and Sales in the Northeaster US
Cell 603 767 5330

On Nov 15, 2013, at 5:22, <crwggb@...> wrote:


I have Trojan Lead acid batteries on my SM SULA. the first set I owned lasted 7 years which by all account is pretty good. The boat was kept predominantly in Northern Europe and was was plugged into shore power throughout the winter whilst ashore.

Sula is now based in HK and got a new set of batteries (Trojans again) when she arrived. She is now in commission 12 months of the year being used regularly and rarely gets plugged into shore power. It is obviously very hot in HK for most of the year. the batteries have crashed after only 2 1/2 years. I was somewhat disappointed with this short life until I read the SM owners manual posted here recently, which stated that 1 1/2 years would be the life expectancy!


I was wondering what other folks experience has been with their batteries. Sula's have always been meticulously maintained, topped up and left fully charged when leaving the boat after use.

Graham Boyd

SM140 Sula

Hong Kong

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