battery charging problem

[fjweaver]

I have bought an AccuMate battry charger for my 2 boat batteries. The lesiure battery Fiamm marine battery (12v - 60AH - 275A) the other is used for starting the engine & seems to be a standard car battery (369/L17). Both are lead acid.
The leisure battery charged for about 1.5 days before the green light showed signifying that the battery was fully charged (I left it charging for 4 days though) - the starter battery went green after only 15 minutes and has now been on for 2 days.
Before charging I topped up the batteries a tiny bit with distilled water. I took hydrometer readings before charging they don’t seemed to have changed since. I was expecting the hydrometer to indicate that both were fully charged.
Now I don’t know if I have:
i) 2 dodgy batteries
ii) or a charger problem
iii) or a hydrometer problem (I checked my car's battery with the hydrometer & it indicated it was fully charged - as expected)

any ideas please?
thanks
Frank


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[perlonious]

hihi

a few questions first
when u topped up the batteries..was there a black scum on the bottom of the cell caps....this would indicate sulphates...if so put 2 tablets of "bataide" from a car shop into each cell...leave for 1 day and then try to recharge again.

next you need to check the voltage of the battery....if over 12.5 volts....then load test them....any friendly car shop will help u out....its a simple machine that puts a big load on the battery and a good battery will hold at between 10.5 and 9 volts....

if ok after all that then its not the battery thats at fault.

so the battery charger would be correct in as much as it cannot pump anymore elec into the battery but with one or 2 cells sulphating and or the link bar between them breaking down, underload the voltage will drop dramatically.


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[halcyon]

What's the hydrometer read ??

Brian

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[fjweaver]

it's a Halford's one and had 3 gradings - charged, fair & needs charging. All the readings are hovering between the fair & need charging modes

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[VicS]

Most likely the distilled water has not mixed with the acid and there is still a layer with a reduced density at the top of all the cells. Check the volts as suggested and if 12.6 or 12.7 all is well. About the only way to get the water and acid to mix competely in a short time is to use a non-clever type of charger and allow it to 'gas' for a while.

<hr width=100% size=1><font color=purple>Ne te confundant illegitimi.</font color=purple>

 

[halcyon]

Did you check the voltages when on charge ?
If not put them on charge and take some voltage readings till the green light comes on, some manufactures have different ideas of what is a fully charged battery.
What is the spec for the charger, seems to be taking a long time to bring it up.


Brian

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[William_H]

I am quite sceptical about smart chargers. Either use a dumb charger with a known current about 2 or 3 amps for a long period commensurate with the amp hour rating of the battery or try leaving the smart charger on for weeks until you can be sure the battery is really charged . I am also sceptical about the value of hydrometer readings. The test for your battery is will it do the job you need it to do? So if the engine start battery will cranck the engine with enthusiasm for about 30 seconds, making sure the engine doesn't actually start then it is ok. As for the services battery try a known bank of light globes and see how long it will supply 5 or 10 amps . If you get about 60% of the rated amphours out of the battery at a finish voltage above 10 volts then it is ok. Check also that your services battery will start the engine and you might check the amp hour capacity of the engine battery with a lamp discharge. The battery rejuvenation tasblets are probably a good idea too.

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[ex-Gladys]

Accumate is only able to cope with limited AH rating batteries, IIRC 60AH... That will be your problem.

<hr width=100% size=1>Larry Botheras

Anderson 26 "Amber"