Can anyone help please. My boat has a 1 year old deep-cycle battery
which my 5hp Mariner outboard doesn't seem to charge any more. On
tickover it engine shows 6V and at high revs shows aound 10-11V. My
local outboard repair shop changed the rectifier and charged me £90,
but this hasn't made any difference - they say the output voltage is
not relevant, only the current - which shows 5A.

I thought the output voltage would need to be around 14V to charge the
battery. Is the regulator at fault ? Any thoughts appreciated thanks.

On 2 Jul 2004 05:58:53 -0700, (Steve Austin)
wrote:

Can anyone help please. My boat has a 1 year old deep-cycle battery
which my 5hp Mariner outboard doesn't seem to charge any more. On
tickover it engine shows 6V and at high revs shows aound 10-11V. My
local outboard repair shop changed the rectifier and charged me £90,
but this hasn't made any difference - they say the output voltage is
not relevant, only the current - which shows 5A.

I thought the output voltage would need to be around 14V to charge the
battery. Is the regulator at fault ? Any thoughts appreciated thanks.

Current and voltage are related - if the charger can only supply 5
amps, and the battery is _really_ dead, so it could take, say, 20 amps
at 14 volts, the charger will reduce its output voltage to the point
that the battery only wants 5 amps.

Do you see this 6 - 11 volts with or without the battery connected?
If it is with the battery connected, then the battery is _really_
fatally dead, and should be replaced.

Lead-acid batteries will self-discharge over time, and if left
discharged will become permanently damaged, and will no longer hold a
useful charge. If you are not using the boat (and therefore charging
the battery) regularly, you should charge the battery once a month or
so to maintain it in good ocndition.



--
Peter Bennett VE7CEI
email: peterbb4 (at) interchange.ubc.ca
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