See full version: Test a Boat Battery
It is always good to check your boat battery because no one wants to be stuck in the middle of a lake with a dead battery. It is also a good idea to test and keep a reserve battery on your boat at all times. There are a couple of ways to test a boat battery but here are the two most common. more
One way is to buy a DC voltmeter to test the battery. First, you will need to disconnect the battery cables. Second, measure the voltage using an accurate DC voltmeter. Last, compare the value with the values below: (Accurate testing depends on the battery not being charged or discharged for 6 hours, preferably 24 hours.)
Load testing is another way to test a boat battery. The device for performing a load test is available at most auto part stores. The amp load for testing should be recorded on the battery by the manufacturer. The load tester puts the battery under stress as if the boat were running and providing an amp reading. If you have a 500CCA battery, the load should test at 250 amps to indicate voltage with load. Reading should be over 11 Volts. Otherwise battery is not able to provide enough power to crank boat. The battery will need charged.
When plugged up & testing on the battery w/ my meter I get 12+V on the front battery but only 10v on the rear. Which means it isn't charging fully. more
Feb 06, 2014 #1 2014-02-06T21:13
Trying to decide if I have a bad battery, or if my charger isn't pushing what it should on one side.
So I'm thinking the rear battery is pulling its charge from the front once the front is full. more
I trust the sears charger. i bought the on board charger so i wouldnt have to climb into the boat and flip the seat to attach the battery charger. i just reach over the gunnel and plug the extention cord in. easy peasy!! i wish i had done that years ago! here
in the last few years these batteries always went to 100% when used with the sears charger. As well during the last year the onboard charger has never let me down. i plug it in the night before i use the boat and I always had full power the next morning!!
Re: how to TEST an onboard battery charger
so I unplugged that charger and I plugged in my sears battery charger. It has a % reading and several other options for charging. its a nice charger. i selected deep cycle and 6 amp charge power and set the one scale on %. the % at the start was about 5%. after 5 hours or so the % was up to 65%, I did this for each battery one at a time. they both didnt seem to want to go past 65%
on another note. since the sears charger wont charge past 65%, is that telling me the batteries are dead. one is only 18 months old. a big interstate deep cycle I bought at the marine mechanics
It is very simple to use a multimeter for testing a battery and it’s also easy to set-up the multimeter. It only takes a few minutes to take readings with a multimeter so you can use it anytime and anywhere. [links]
Turn on the battery and the multimeter. Once you place the wires onto the battery terminals you shall notice the movement of the multimeter needle.
You must have heard about “testing a deep cycle battery“. When you test a battery, you get to know whether your battery is capable enough to be compared with a brand new battery or not. here
In order to do so, you have to use the battery for 5-10 minutes. Do not overuse as it will drain the battery and hence lower down its voltage value. [links]
Also, do not use a trickle charger because it keeps on charging the battery even after it’s fully charged and you must be knowing that overcharging is also harmful to a deep cycle battery.
There are no prongs used in a multimeter as used in a voltmeter.