Very dry dry cell batteries!

[woodstock]

Hi everyone. Perhaps someone might be able to help...

A month ago now I checked the battery fluid levels and founf them to be very dry in most cells - hadnt checked it for a month before that!

Since that time I have been regularly checking and have been surprised at how much I have to top them up ( probably some cells at least once a week). Its difficult to say but I get the impression that it is necessary more when we are connected to shore power- which latterly has been quite a lot of the time . The worry is of course that the 90 amp charger is cooking the batteries - there is a temperature sensor in the box and I have never fellt the batteries to be warm even - but they are always bubbling away cos we are using thenm 24/7! Some of the plates are a bit bent on the top- presumably it happened when I let it go dry .

They seem to be working well and holding their charge. this next trip will be the longest for a while - but we have had a week out at anchor and there appeared to be no problem. Maybe its normal to use that much water in a warm climate and 24/7 use?

What I want is instructions how to do a test. Either SG ( for which I would have to buy a SG meter - in Spanish - might be dodgy. preferably I need instructions how to do a "drop test" or some such thing to objectively test their function as if necassary I should be able to buy new in las palmas.

Hopefully wont need to!

 

[rivonia]

Sport cruisers need BIG BIG batteries. You have a serious problem! Do not leave a battery charger connected to the batteries UNLESS it has an autoamatic cut off when the gassing level is achieved ie 14.2 V. Better still get a simple battery management system from some-one like Sterling. Good luck.
Where abouts in Spain are you?

Peter

 

[Sandyman]

They are not bubbling away cos your using them 24/7 but because they are being charged 24/7 and being cooked. It cannot be anything else if you are having to top them up that often. As suggested you need a battery management system and you need to take an urgent look at your power consumption.

The SG meter (never heard one called that before) to which you refer is called an hydrometer.
Plenty of info on the net. Just Google ''battery maintenance'' and ''how do I use a hydrometer''

 

[cimo]

not sure if it needs to be said or not but.............
hope you got good ventilation through your battery compartment(s). If your batteries are boiling, you are producing hydrogen gas. which tends to clump together in pockets, floating upwards & is known to be explosive.

take care.

(downstairs smoker).

 

[oldharry]

not sure if it needs to be said or not but.............
hope you got good ventilation through your battery compartment(s). If your batteries are boiling, you are producing hydrogen gas. which tends to clump together in pockets, floating upwards & is known to be explosive.

take care.

(downstairs smoker).

Same gas as was used in the ill fated R101 airship.

 

[fergie_mac66]

had to pipe battery gas out board for a BW compliance test.Quite a few boats have gone bang a good few years ago tho.

Sound like your charger is faulty