New boat batteries

[Fisherman]

http://"People kill more deep cycle batteries with poor maintenance practices, than die of old age!" Lead sulfation actually starts when you remove the charging voltage a lead-acid battery. The lead sulfate crystals are converted back to lead during the normal charging cycle. The real question is, if all of the lead sulfate crystals are not turned back into lead, how long does it take before they become so hard that they can not be converted? The answer is that varies--it could be weeks or months and depends on a number of factors such as the quality of the lead, temperature, plate chemistry, porosity, Depth-of-Discharge (DoD), electrolyte stratification, etc. Porosity is a measure of how porous the plates are. During the normal discharge process, lead and sulfur combine into soft lead sulfate crystals are formed in the pores and on the surfaces of the positive and negative plates inside a lead-acid battery. When a battery is left in a discharged condition, continually undercharged, the electrolyte level is below the top of the plates, or the electrolyte is stratified, some of the soft lead sulfate re-crystallizes into hard lead sulfate and it cannot be reconverted during subsequent recharging. This creation of hard crystals is commonly called permanent or hard "sulfation". When it is present, the battery shows a higher voltage than its true voltage; thus, fooling the voltage regulator or smart charger into thinking that the battery is fully charged. This causes the charger to prematurely lower its output voltage or current, leaving the battery undercharged. If a wet lead-acid battery is not periodically recharged, undercharged or not properly maintained, sulfation will account for approximately 85% of premature battery failures. The longer sulfation occurs, the larger and harder the lead sulfate crystals become. The positive plates will be light brown and the negative plates will be dull, off white. These crystals reduce a battery's cranking performance, capacity, and ability to hold a charge or be recharged. This occurs deep cycle and some starting batteries are typically used for short periods, seasonal powersports or applications, vacations, weekend trips, etc., and then are stored the rest of the year to slowly naturally self-discharge. Most starting batteries are normally used several times a month, so sulfation rarely becomes a problem unless they are undercharged or the plates are not covered with electrolyte. As a consequence of parasitic (key-off) loads or natural self-discharge, permanent sulfation occurs as a wet lead-acid battery discharges while in long term storage. Parasitic load is the constant electrical load present on a battery while it is installed in a vehicle even when the power is turned off. The load is from the continuous operation of appliances, such as an emmissions control unit, clock, security system, maintenance of radio station presets, etc. While disconnecting the negative battery cable will eliminate a parasitic load, it has no effect on the natural self-discharge of a lead-acid battery. Self-discharge is accelerated by temperature. For batteries that are over 77° F (25° C), the self-discharge rate doubles with a 18° F (10° C) rise in temperature. Thus, sulfation is a huge problem for wet lead-acid batteries not being used, sitting on a dealer's shelf, or in a stored vehicle, especially in HOT temperatures.

[NANUK]

LOL

The wonderful world of www has an endless supply of cut & paste information and some wonderful theories

In a perfect world under perfect conditions, an on board charger should perform as good as the description on the box, BUT in reality, there are too many variables, like quality/make of charger, condition of batteries, wiring, location and embient temprature (or in some cases a closed compartment temprature during charging) etc.

I deal with 36v auto floor scrubbers on almost daily bases, all have 12v heavy duty commercial duty deep cycle batteries and come with state of the art microprocessor controlled automatic chargers.

I have seen a few "cooked" batteries and heard of a few fires because on board charger was left plugged in, Had endless discussions with battery wholesaler and technician, nobody can argue that in theory an on board charger is better and very convenient, but in reality there are too many variables like I mentioned above.

Mybe its just me, but I just don't like to take my chances with today's offshore made "reliable" electronics.

Besides, I figure if every time before charging, I have to open the battery compartmant, battery box and the compartment where the on board charger is mounted (ventilation), I would be better off to just use a good quality portable charger with charge rate and charge level display, I have it sitting somewhere where I can read this information every time I open the garage. and disconnect it when the battery is fully charged.

 

Do whatever works for you, specially if you are getting over 10 years out of a single battery,

To be honest, I have never heard of such long usefull deep cycle battery life.

 

To each his own.

Edited October 11, 2014 by stonefish

[irishfield]

8 summers on my deep cycles in the bow of my Lund... they're about done, but from neglect. 8 summers on the AGM's for the Verado and kicker motor and they still load test as new. Battery in our steel boat w / 25 Honda.. 9 years / 10th summer and it load test as new. Moral to the story... use your boat!

 

As for leaving chargers plugged in overnight or 24/7... like Stonefish... not a chance! As matter of fact I forgot that I plugged my cordless 18v battery in yesterday morning and opened the shop to lithium ion gas today and a liquid pool of battery goo, deformed charger and melted battery pack. Thank god I set it on my steel jig table, although I found it all on the floor. Got so hot and bubbling I guess it hopped itself right off the table!

[Mister G]

I must be the lucky one because my boat has been on charge when not fishing for over 15 years. But that's what everyone says when we go fishing too.

 

Last cranking battery was 9 years old and I only changed it out because it was 9 years old.

 

Life is good and my on-board charger makes it even easier and one less thing to worry about.