i noticed one of my batteries was flat
took it out to charge , added a little distilled water put it on my charger
now all but one of the cells it bubbling away and read ok with the hydrometer
is this holding a charge or do all of them need to be working?
should i get gid of it and get a new one?
thanks in advance
scotty
Mate, you have "dropped" a cell by the sound of and the battery is stuffed!
A real "country butchers method" of proving this is too whack a big screwdriver across the terminals - if the suspect one doesn't erupt in bubbles, that will prove it but I think taking it to the local battery guy who can do a proper load-test on it might be a bit more sophisticated though less spectacular!
Quite commonly, the voltage output from the battery can still show around 12V and that muddies the water a bit and makes you think it is OK.
In fact, when you hit the starter, this cell will collapse completely and most likely you won't get a start!
Slashing a screwdriver across battery terminals can be a short cut to hospital.... strongly disadvise this particularly on a bigger battery.
It does however sound like you have droped a cell.
the best thing is to test it with a tong tester ( I mean a tong tester not a current clamp), This will load the battery and give you a voltage reading, usulay expressed with a good, bad, uggly marks on the scale....these days they have battery clips rather than tong probes..... they arent all that dear thes days.
failing that hook it up to crank and measure the terminal voltage while cranking and compare whith a known good similar battery.
How old is it?
If it is over 5 years old you have done very well out of it.....take it to be recycled and buy a new one.
cheers
Its the details, those little details, that make the difference.
need a new one buddy
old battery is now at the battery shaop and new one purchased
not sure how old it was as it came with the boat
thanks
Ahhhh happiness is a new battery
cheers
Its the details, those little details, that make the difference.
Many new batteries don't make the specs they quote. Get the shop to properly charge and test it before it is fitted. Many marine alternators on outboards are pretty average and will never fully charge a battery from scratch. They may never charge battery styles they weren't designed to charge properly / safely.
Have recently helped a mate who purchased new batteries and the amount of charging these required was silly to get fully charged. In a boat they would never have got it. Returned one as it was not coming up to voltage spec nor the acid density of other cells.
Too important with marine batteries to check prodction date when you buy as a stale battery will always underperform. Get what you pay for and remember the differences between marine cranking amps and Cold Cranking amps.
its a sea master brand so both are now the same
the new one went on the charger before i fitted it and it has a charge indercator on it
it wa ony on the charger 10 minutes before it was fully charged
comes with a 12 month warrenty
so should be ok if i check it more regular than before
scotty
I think there are three problems here.Originally Posted by cormorant
1. stale batteries that have not been looked after in storage.....if a battery isn't at pretty near full charge at time of purchase I would not wish to have that battery........lead acid batteries do not like to be left at a low state of chsrge for an extend period......another good reason to purchase batteries from a source that turns over stock quickly.
2. so many of our boats do not run their motors for sufficient time to charge a battery......how many boats out there would get less than 1 hour run time everytime they go out......then they get out only every couple of weeks.....even a modern car with the correct battery and significantly larger charging capacity would have problems under these conditions.
3. how many people have purchased a coppy of the service manual specific for their motor and have installed the recommended size of battery.
for my motor to charge my battery from half flat ( as flat as you want a lead acid battery to go) would take about 3 hours of runing above idle.
How many small rigs get 3 hours running on an outing...I would get about 5 maybe 6 hours on a tank.
My car would do the same job on the same battery in about a hour
I do not think it is fair to say most outboard charging systems CAN NOT charge a battery to full charge.....I think it is more about how we use our boats.
how much current does your charging system deliver? and what is the capacity of your battery?
In my view these are important things to know.
cheers
Its the details, those little details, that make the difference.
On behalf of ALL the VMR's and Coast Guards... thank you
One less jump start call out or tow job
hi cormorant,
would this explain why my new marine pro 400 never seems fully charged?? have taken it back, they have charged loaded and tested etc all OK, luckily the 40hp 4st honda dosent take much to start (can easily pull start if needed). i was getting up the kids for turning lights etc on, now I am a bit more vigilant and turn the islator switch off.
would sticking it on the charger every so often solve the problem??
have been wondering if i have an alternator problem or something, previous battery was a marine pro 400 and i got about 7 years out of it.
probably run the motor for at least 3 hours per trip
cheers
dazza
I sugest you need to assertain the charging conditions.
does your sounder have ability to display a voltage reading.....you should be able to see the voltage rise after cranking.
The general expectations and understanding of outboard charging systems is soo poor that many people do not know if the charging system is working at all.
My young brotherinlaw ran his boat oblivious to the fact his charging system was stuffed for many years....it wasn't till I did some tests and baught the manual that we knew for certain the regulator was pffhT ssspT broken.
if you have access to a volt meter and a decent charger you should be able to do some observations.
cheers
Its the details, those little details, that make the difference.
oldboot,
how do i go about assertaining charging conditions?
no my sounder hasn't got volt display,
you are spot on about understanding charging systems, i turn key and she goes, that is about the sum total of my knowledge
but in saying that electronics etc are not my area of expertise, putting broken humans back together is.
i guess i need to get a multimeter, when motor cranks volts should drop, once running should be putting out about 12 volts??
am i on the right track
cheers
dazza
Mate if you have a quality charger it would be good idea if you want a battery to last it's full life expectancy to keep it fully charged as much as possible but not overcharge it. Having a largish battery and a smallish alternator is Ok as long as the alternator has the ability to charge the battery but use of accessories on a larger battery and a small charging system may mean it never has a chance to fully charge a battery. This also means the motors alternator is running flat tack all the time. The more promptly after discharge a battery it is fully recharged the better it is for it.
Mates who troll a lot have had issues a sat idle speeds the outboard alternators on some are pathetic and with sounders etc running they have had constant battery issues.
\
Dazza the voltage purt out by voltage reg should ( check your manual or internet) be more likely up to 13.6v to 14.4 v but always more than 12 on the charge circuit
Crude and rude summary of voltage observation.
The battery voltage is nominaly 12 volts DC
A healthy fully charged battery at rest.....( been sitting doing nothing for at least half an hour) should be arround 12 to 12.5 volts... maybe a little more.
Any battery below 12 volts is in a discharged state......
many argue that it is best to not allow a battery to get below 11.5 volts resting
A battery should not be allowed to get below 10.5 volts resting... very flat not good for the battery.
Batteries may be charged with voltages from 12.8 Volts (ish) up to 15 volts.
It is accepted that 13.8 volts is the best long term charging voltage, bleow that charging will be slow above that and there is (some) risk of overcharging in the long term.
It is reasonable to charge a battery at 13.8 volts indefinitely.
15 volts is considered the maximum safe voltage for rapid charging, but batteries should not be left at this voltage for extened periods or unsupervised.
Now under heavy load ( cranking) the terminal voltage may drop quite low.....depending on battery, size, condition and how heavy the load is......anywhere as low as 8 volts but often arround 9-10-11 volts.
so typical observations
charge the battery under observation using a standard charger till the electrolite gasses freely...you can see and hear this.
measure the terminal voltage while on charge ( could be confusing with a clever charger)
Rest the battery for at least an hour.
measure the voltage
crank the motor and observe the voltage while cranking
allow the motor to start.
measure and observe the voltage over the next 10 minutes
after cranking stops the voltage should increase immediately back to a " normal state" ( 12 volts ish) and then steadily increase to the charging voltage of the motor problay between 13.5 and 14.5 volts.
cheers
Its the details, those little details, that make the difference.
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