full traction these batteries come in either 2 volt cells or 6 volt cells, and will last approx
How many batteries do i require?
the simple answer is the more the better, but most people are restrained by cost and size, this question i always throw back and ask you how long do you want the electrical system of your boat to be supported after the engine is switched off? in most cases the answer is 24 hrs, then add up your consumption ( 30 ft boat fridge = 5 amps, lights at night averaged out over 24 hrs = 5 amp/hr, total = 10 amp hr x 24 hrs = 240 amp/ hr add on 40% ( an empty battery is still about 40% full ) = about 300 amp hrs, ie three batteries of the
What type of battery do i use ?
the type of battery used depends on your priorities, if you are worried about turning the vessel upside down and require no spillage of leakage then go for sealed batteries or gel ( but to not complain when the high charge rate obtained by conventional batteries is not attainable by these types ) my personal definition of a good battery is one i can charge with as much current as possible in order to charge them as fast as possible ( because you do not want to waste engine hours ) with minimum damage to the batteries, this can only be obtained by using open type lead acid.
will your charger boil my batteries ?
quite simply yes and no.
no if: you look after your batteries, you check your oil level in the boat and water level, just because you never
check it in your car do not assume the boat duty cycle is the same. not only must you check the water level, check that with the charger or alternator on that when you look inside the battery cells a slight tap on the battery side should release small amounts of gas from all the cells, any cell not gassing remove the battery. expect to top up a battery, if you top up 5 cells and one requires no water scrap that battery. if when the charger or alternator is on and the batteries become warm or hot check the battery voltage, if the battery voltage is 14 volts or less and the batteries are boiling the fault is the batteries. if the batteries are 15 volts plus, the fault is the charger or alternator. do not fit a battery charger on to old batteries and go home, it is important to keep and eye on the batteries as a battery charger has all week to boil old batteries where an alternator only has a few hours, that is why most boiled batteries occur on a battery charger, and one must be able to distinguish between faulty batteries and a faulty charger
yes if: the batteries are on there last legs, batteries fail in four main ways ,
1)sulphate on the plates, this is due to a low voltage bad charging system, this will allow a coating on the lead plates to develop thus rendering the battery ineffective, this has the effect of no charge going into the battery, and is not actually a battery failure yet accounts for the largest proportion of battery replacement ( most times recoverable over a period of time if you fit an advanced regulator on the alternator or use a constant current battery charger with a high voltage charge cycle )
2)where a battery has had a hard use and the lead which is discharger from
