Batteries Gassing

[Sundowner 39]

Hi All
Recently my gas alarm haste been activated after a couple of hours with the battery charger on....I have a 30 Amp charge linked to a battery bank of four 110amp batteries of three years old....I also have two 105w Sola Pannels each on there own MPPT controller.

Is gassing likely caused by over charging or battery failure or both

 

[RichardS]

Yes, it could be either. Can you check the voltage going into your batteries with a meter with nothing drawing any current? If the voltage is being sustained above about 14.4V then I suspect something is not right with the charger or the controller. If it's less than 14V then there's probably something wrong with the batteries.

Are the batteries sealed or are you topping them up with water more than usual?

Have you noticed any degradation in the performance of the batteries?

Richard

 

[Mistroma]

Yes, could be either

If nothing has changed I'd check batteries first. However, something might have changed to cause overcharging (less usage, more motoring, more time on shore power etc.). That could show up gassing if some regulator settings were too high for your batteries. Less likely than battery issue.

Why don't you simply check the battery electrolyte S.G. with a cheap hydrometer. That will give a lot of information, especially if done regularly before and after charging to spot trends. Should be obvious with one set of readings if a cell is dud. Don't check when charging, allow time to vent and don't have a ciggy in your mouth. Also monitor the voltage when charging to see if it is unduly high.

EDIT: Too slow, beaten to it by Richard.

 

[macd]

Sundowner: what type of batteries? Sealed? Or open (i.e. with caps so they can be topped up with water).

Yes, vigorous gassing can be a sign of battery damage or excessive charging.

However, open lead acid batteries should gas. Gentle gassing is good for them, but clearly means they need topping up from time to time. So-called calcium batteries (they're lead alloyed with a few % of calcium) will gas less than lead-antimony batteries at the same charging voltage. Most sealed batteries are calcium-lead.

If they're open, far the best means of assessing their condition is, as mentioned, with a hydrometer.

A final thought: charging voltage should be reduced as ambient temperature rises. (A quality charger/controller will either compensate for this, or allow you to change it.) Has it been unusually warm where you are?

 

[Sundowner 39]

Third attempt at reply wifi shaky here.
Vented batteries.....not topping up more than normal....they seem to charge at a much slower rate....The bank is 550 Amp....the charger is a Guest 30 Amp charge pro model 2630 .......Normal use we are live aboard and it is quite hot we are in Trinidad.
I will try all the groups suggestions over the next few days. Thanks.

 

[macd]

The bank is 550 Amp....the charger is a Guest 30 Amp charge pro model 2630 .......Normal use we are live aboard and it is quite hot we are in Trinidad.

I was unable to find a manual for that model, but could find one for its 20A little brother. Is yours a triple output version? If so I presume you're limited to 20A per bank, which is a bit limp for your 550Ah battery bank.

There's no mention of automatic temperature compensation, nor any manual adjustment of same. Peak charge voltage is described as 14.3A which should cause little or no gassing, even where you are. As said, light gassing is good, not least in deterring sulphation. (For comparison ours charge at up to 14.8V, compensated for temperature, but I'm absolutely not suggesting yours should run that high.)

Other than the engine, are there other means of charging such as wind or solar? A fault in the controller of either could cause excessive charge voltage.

As indicated before, you need to ascertain what voltage is actually going into the batteries, and their SG.

 

[Sundowner 39]

It is the triple ,but is only feeding one bank so should give max charge.....I do have solla .....two banks of 105amp on separate MPPT controllers .
I have a BM 2 NASA battery monitor which this morning was showing 12.6v and solla charge of 1amp at 62% power.....I then switched on the Guest which displayed a change of 15amps after 20 minutes it is now showing 13.3v and a charge rate of 6.6amp at 68%.

I have been unable to source a hydrometer yet but will have one soon....

 

[macd]

It is the triple ,but is only feeding one bank so should give max charge.....I do have solla .....two banks of 105amp on separate MPPT controllers .
I have a BM 2 NASA battery monitor which this morning was showing 12.6v and solla charge of 1amp at 62% power.....I then switched on the Guest which displayed a change of 15amps after 20 minutes it is now showing 13.3v and a charge rate of 6.6amp at 68%.

I have been unable to source a hydrometer yet but will have one soon....

I suggest you disconnect the panels (or cover them, or wait for dark) if you want any meaningful information about your charger. On the face of it, 13.3V from the charger (+ solar?) is very low (the opposite of what your original concerns might suggest).

 

[TQA]

Sounds like you may have a cell that is failing. It will gas and show a lower voltage than the other cells.

 

[Mistroma]

It is the triple ,but is only feeding one bank so should give max charge.....I do have solla .....two banks of 105amp on separate MPPT controllers .
I have a BM 2 NASA battery monitor which this morning was showing 12.6v and solla charge of 1amp at 62% power.....I then switched on the Guest which displayed a change of 15amps after 20 minutes it is now showing 13.3v and a charge rate of 6.6amp at 68%.

I have been unable to source a hydrometer yet but will have one soon....

Get a Pro Hydro Volt hydrometer if you can. They are much easier to read than Halfords glass tube type and also do automatic temperature compensation. Remember to flush with water after using as I've heard that the colours vanish from the dial if it is stored without rinsing.

I could only find one on eBay just now, priced around £10 but delivery was £8.50. I bought mine from the same seller (onsolar) for £10.67 a couple of years ago but delivery was free.

 

[macd]

Get a Pro Hydro Volt hydrometer if you can.

Getting one in Trinidad might be tricky, but otherwise a definite +1.
I bought one on recommendation here (possibly by you, Mistroma, and if so, thanks).

 

[lpdsn]

I very frequently get the batteries setting off the gas alarm. It's been happening for years ever since I upped the shorepower charger to 14.8V (about 8 years ago). It is not an issue. I check the water level every few months and top up about every 9 - 12 months or so. The plates have never been uncovered. So no panic.

I put it down mainly to there being an easy pathway for the H2 to get to the gas sensor. Leaving hatches open gives it another route, which helps a bit. I keep telling myself it's good to know the gas alarm actually works.

Batteries are in good condition for 8 year old batteries.

 

[geem]

I very frequently get the batteries setting off the gas alarm. It's been happening for years ever since I upped the shorepower charger to 14.8V (about 8 years ago). It is not an issue. I check the water level every few months and top up about every 9 - 12 months or so. The plates have never been uncovered. So no panic.

I put it down mainly to there being an easy pathway for the H2 to get to the gas sensor. Leaving hatches open gives it another route, which helps a bit. I keep telling myself it's good to know the gas alarm actually works.

Batteries are in good condition for 8 year old batteries.

Our boat was designed originally with a dedicated battery compartment with 10mm perspex lids. The lids sit on seals and are under the starboard saloon seats. The battery compartment has a dedicated ventilation system with two inch diamter ducts for air in and air out to a dorade box. Also inline is a centrifugal fan that can be switched on. This fan was originally wired via a relay such that when the battery chager was switched on, it switched the ventilation fan on. The compartment holds two 125 amp hr engine start batteries (24v system) and four 225amp hr domestic batteries. A pretty sophisticated set up for a boat designed in 1977. With open cell batteries it still works brilliantly today.

 

[lpdsn]

A pretty sophisticated set up for a boat designed in 1977. With open cell batteries it still works brilliantly today.

Maybe someone at the builders/designers had experience of larger scale installations. Submarines perhaps?

 

[geem]

Maybe someone at the builders/designers had experience of larger scale installations. Submarines perhaps?

Designed by Van da Stadt

 

[lpdsn]

Designed by Van de Stadt

Mine too. By 1992 they seem to have been happy with batteries under the bunk and simple plastic vents to let the H2 out.

 

[geem]

Mine too. By 1992 they seem to have been happy with batteries under the bunk and simple plastic vents to let the H2 out.

The later Trintella 45 fron 1986 didnt have the ventilation system either. I suspect cost cutting as the later Trintella has balsa cored decks where as our 1980 model has Airex cored decks.