On Sat, 20 Jun 2009 18:00:46 -0400, jeff wrote:
Tuuk wrote:
Hi
I bought the two Nautaulis deep cycle big batteries for 139. ea. Also the
motomaster 10/2 amp automatic charger regurlarily 70.
I have had the 2amp charger on one of the batteries for about 6 hours or 8
hours and little bubbling going on I can hear and the charger still is not
changing from red light (charging) to green light (charged).
Should I keep it on the 2am for longer? Batteries are only 1 week old from
Canadian Tire and charger is also new.
random thoughts:
Its hard to say about the bubbling because a small amount of bubbling is
expected, but a large amount means possible overcharging. As others
say, get a simple Voltmeter and a cheap specific gravity tester - you
can get both for under $10. And of course make sure the battery has the
proper amount of distilled water.
Your batteries hold a bit over 100 Amp-hours, meaning that if the were
totally dead it would take over 50 hours for your 2 Amp charger to get
one close to full. The last 10% could take some hours more. However,
they should have be delivered with at least a 50% charge - otherwise
you'd have a case to return them as DOA, since taking them below 50%
diminishes the lifetime. Look for a manufacturing code to make sure it
hasn't sat on the dealer's shelf for 6 months or more.
That said, I would expect the batteries to need a significant initial
charge (unless the dealer claimed they were fully charged) so the 2 Amp
mode really will take overnight or more to get it up to full. Or you
could use the 10 Amp mode to do it faster. BTW, I regularly charge at a
rate double that (scaled for my larger bank) but my charger is well
controlled so it doesn't apply too high a Voltage. In fact, the
purpose of a deep cycle battery is to be able to take them down to about
50%, and then recharge them reasonably quickly, and repeat this about
500 times. If you really want to charge at a slow rate, this is the
device to get:
http://www.amazon.com/Battery-Tender...dp/B00068XCQU/
You would have a hard time seriously overcharging a 100 amp hour
flooded deep cycle battery using a 2 amp trickle charger.
Being a new battery, it probably has never been fully and properly
charged. Battery charging is more complicated than merely stuffing
electricity back into the battery. The last 5-10% of capacity is the
hardest to achieve.