the plates falls to the bottom of the
battery, this will at some stage cause
that battery cell to short out and cease
to exist as a cell, this in effect causes the
other cells to over charge, and as a result
the water in the batteries is slowly ( at
first ) gassed of, as the water level
drops down the plates the gassing
increases and increases until the battery
gassing verses plate exposed goes into
an exponentially catastrophic failure
resulting in the boiling of the batteries,
the only good thing about this type of
failure is the knowledge that at least you
used the batteries to there maximum.
this failure can only be predicted by
regular battery checks and you will
notice 5 cells low on water and one not,
it is important to scrap this battery in
order to prevent boiling.
Battery chargers in general:
3)
Poor maintenance of the batteries ie
most members of the public make the
checking water level, permits the level
same mistake when buying marine
to drop below the plated, this has the
battery chargers, they simply go into a
effect of reducing the voltage of each
chandlers and ask for a 50 amp charger,
cell , and in effect causes the batteries to
there may be a choice of two 50 amp
boil with a perfectly good charger
charger, one at x pounds and one at y
4)I
in the event of a charger failure the
pounds with about 30% - 50 % cost
charger regulator could fail causing the
difference between them, in most cases
full current of the charger to be pumped
they go for the lower cost unit.
into the batteries causing a fast boiling
it is very important that you stop buying
in this case expect to see a battery
battery chargers based on amps as this a
voltage of 15 volts plus.
totally irrelevant figure, most people
What do i look for and how do i stop
when they buy a 50 amp charger are
my batteries boiling ?
under the illusion that they can then run
Boiling a battery is almost inevitable if
50 amps worth of kit from shore power,
you do not look regularly at your
how wrong can you be, in order to run
batteries to prevent them boiling, where
that 50 amps worth of equipment you
as there is no doubt that the final act of
would require a charger to give 50 amps
actually boiling the battery only takes a
at 12.6 volts = 630 watts output power.
few hours, the signs were there 4 weeks
however if the charger is a standard
before, but you never bothered to check
transformer unit it may only give 50
your batteries, therefore the first thing
amps at 4 volts and only at 16 amps at
you knew was the nasty acid smell in
12.6 v = 200 watts, where as a constant
the boat.
current charger or switch mode power
simple battery checks
1) check water level, expect to top up (
this is good and shows your batteries are
performing well ), the water used varies
from none ( low charge rate week end
boat ) to 8-10 litres per year ( heavily
used boat )
2) switch on charger, after 5 hrs plus
remove all lids, ensure all cells are
gassing, remove any battery with a cell
not gassing, with 24 volt system replace
both batteries and not just one.
3) if when topping up a 6 cell battery (
12 volts ) 5 cells take much more water
than the sixth replace this battery .
4) if the batteries boil: if the voltage is
less than 14 volts the batteries are the
problem, 15 plus the charger is the
problem.