Battery Charger / Rotten Egg Smell

[Harlequin]

This is worth a read...

batteryuniversity.com article on charging lead acid batteries

[Squanderbucks]

This situation is nothing to take a wait and see attitude about. You can go through he steps recommended above - but do it quickly. Disconnect the charger.
Take temp reading of the batteries and disconnect them from everything.
See if the temp continues to rise.
If so - get them out of your boat.
Do not sleep on the boat with the gas going off.
Do not light any fires near the batteries.

I recommend getting them off your boat and doing the testing if you really want to spend time on these batteries for an intellectual process to try and determine what is the exact cause of the failure.

Explosion and fire can be very real issues when smelling get strong enough to get your immediate attention.

I realise that many people are sensitive o many boat smell such as diesel, gas, funky bilge water, etc. But if this is something different that the usual small of your charging batteries - it is surely a battery failure and they need to be gone.

[hamburking]

Originally Posted by mvmojo

^^^ THIS! ^^^^
A shorted battery cell is very dangerous. If you have a battery fire, it will in all likelihood burn through your hull! It will probably also set the boat on fire, but since the boat will be sinking the fire will go out pretty quickly. If you can smell hydrogen sulfide something bad is going on.

Thermal runaway. Avoid at all costs.
New batteries are cheap compared to a new boat.

[Mike Banks]

This, contrary to some posts is NOT normal. It means that one or more batteries has/have reached too high a concentration of sulphuriuc acid, probably because of insufficient water or overcharging, and now the acid is breaking down to hydrogen sulphide and water.

The smell is bad enough--but this gas is extremely toxic.

Check your batteries and charger, batteries for water and charger for too high a voltage, or the regulator that should control the rate of charge is not working. Some chargers do not have a regulator or temperature monitor--those have to be checked all of the time for rate of charge and charging voltage. The battery producing the H2S is probably kaput, but fresh electrolyte after a wash-out of all cells might fix it, but usually replacement is required.

[Larry Douglas]

We carry and regularly use a battery hydrometer which helps to identify bad (and weak) cells in lead acid batteries. I agree with the others who are cautioning you that this can be a dangerous situation. H2S is corrosive as well as dangerous, so you need to solve this issue ASAP. Also, be aware (you probably already know this but others may not) that you can not parallel old and new batteries on one charger and should not parallel batteries with different capacities even when all are the same age.

[Harlequin]

PS. For completeness, and for others who may be experiencing these symptoms but not from charger/shore power, this can happen with a duff alternator regulator as well.

Only a few days ago, a friend described how he'd cooked his start battery after only a few hours motoring with a defective regulator. Again the tell-tale 'bilgey' sort of smell, but again "It seemed to go away".

Took him a while to remember to double-check, only to find his battery seriously cooking off. Another close call.

Not something to be messed with. Learn from others' experience, or risk losing more than just a battery!

[PPS. Our new Victron Phoenix charger comes with a battery temperature sensor. ]

[hzcruiser]

Originally Posted by Mike Banks

This, contrary to some posts is NOT normal. [...]

Correct! It's still surprises me how often some members are blaze about serious risks to health and equipment.

[davewtsnape]

You've cooked your battery! Probably one of your batteries has a dead cell and will now only reaf 9v. Replace immediately, sorry. Happy Xmas.

[davewtsnape]

You've cooked your battery! Probably one of your batteries has a dead cell and will now only reaf 9v. Replace immediately, sorry. Happy Xmas.

[senormechanico]

All this makes me REALLY glad we switched to LiFePo4, both in the boat and and home grid tie.
It's been several years and we never looked back. Absolutely NO regrets.

There are only two FLA's in our lives, both car batteries.

[sailorboy1]

Im glad I read these mainly for amusement

[GarthGregory]

If you are smelling H2S ( rotten eggs ) there is a problem ,under the right conditions, that gas is explosive , a small amount off gas is usual ,one would not normally notice the smell . Probably one or more cells are dead , have it checked, if you cannot yourself .

[Harlequin]

Originally Posted by sailorboy1

Im glad I read these mainly for amusement

Happy to oblige...

[ronbo1]

Harlequin,

Your pix certainly got my attention! Thanks.

Which reminds me...at my marina in NY some boats on the hard have their shore cables plugged in all the time. Presumably their chargers are on and unsupervised. The marina forbids this practice and I don’t mind once in awhile enforcing it.

Ronbo

[curtis742]

Buy a hydrometer, a good one, they look like a turkey baster. Check the specific gravity of each cell. One weak cell in a battery will draw all the cells in the entire bank down to the voltage of the weak cell draining all the batteries in the bank. If a weak cell is found remove the battery from the bank to stop the drain on the system. Generally it is not good to introduce a new battery into an old bank. The lower state of the old batteries will drain the new on to their level and wear out the new battery prematurely. I would replace the entire bank and add the older but still functional batteries to another bank on the boat consisting of batteries of a similar age. A cell to cell test can be performed using a dvom. Each cell should read 2.5 volts approximately when fully charged. Be sure to rinse off the test leads when done. Remove the caps and test cells 1-2, 2-3, 3-4 etc and record the results. Do not test immediately after adding water as this will skew the results.