Lead Acid explosion

My first set of lead acid batteries lasted 20 year so when Covid came, I upgraded my power system due to a failed battery.
I hooked up the new battery set to a new Victron and installed an automatic watering system.

Last month after 3 years of easy use the batteries were acting odd. Voltages were going weird and I was due to take the watering system apart and check the levels.
The hoses were turning a green colour.

When I checked individual voltages got odd readings. When I checked the 24v terminals of my 2 connected batteries.......Boom!.
I stood there stunned and my wife runs out. Deaf in one ear am bewildered.
The system still works when I see acid leaking.
When I removed the batteries found virtually no acid. All the floats showed full and rarely used water.

Looking back I wouldn't use any water system and the greenish colour was a sign of gas. Checking them manually worked hood for the previous 20 years. When a spark was produced the 2 batteries exploded because they were mostly gas.
I did receive a pro rata refund from battery retailer and now use lifepo4. Fingers crossed.
In the end it all worked out.

I had a manual pumped water system and it was absolutely wonderful for about 12 years. However lithium is far and away better.

My 30kWh forklift FLA is now 19 years old. Got it free about a year ago and being cheap have continued to use it although I have bought almost 100kWh of lifepos. Using watering system too, but once a week I knock on those floats when battery is full to see if there's stuck ones. Every now and then there is one, but it opens easily and usually works next time when tested.

Lifepo is so much better battery chemistry for solar if you can place it somewhere with 15-20C all year around.

The lifepo4 are in the mudbrick house in a section off room with access outside only.
Temp is 15c to 23c year round

onrbikes said:

My first set of lead acid batteries lasted 20 year so when Covid came, I upgraded my power system due to a failed battery.
I hooked up the new battery set to a new Victron and installed an automatic watering system.

Last month after 3 years of easy use the batteries were acting odd. Voltages were going weird and I was due to take the watering system apart and check the levels.
The hoses were turning a green colour.

When I checked individual voltages got odd readings. When I checked the 24v terminals of my 2 connected batteries.......Boom!.
I stood there stunned and my wife runs out. Deaf in one ear am bewildered.
The system still works when I see acid leaking.
When I removed the batteries found virtually no acid. All the floats showed full and rarely used water.

Looking back I wouldn't use any water system and the greenish colour was a sign of gas. Checking them manually worked hood for the previous 20 years. When a spark was produced the 2 batteries exploded because they were mostly gas.
I did receive a pro rata refund from battery retailer and now use lifepo4. Fingers crossed.
In the end it all worked out.

Click to expand...

Curious what the capacity of your battery bank was in total and what your charge rate was?
Charge controller voltage settings?

onrbikes said:

automatic watering system

Click to expand...

I've been wondering how well those work, for golf cart use, I guess I'll stick with manual watering till the golf cart market for LFP matures. 8*)

seneysolar said:

Curious what the capacity of your battery bank was in total and what your charge rate was?
Charge controller voltage settings?

Click to expand...

The first set was 12 x 2 volt 600 ah.

Charging was so various. The last 5 years they were high maintanence and they used a lot of water.
I recall I would equalize once every 2 weeks up to 30v.
The batteries dod have an easy life here though.
Atv the end I also threw caustic soda I them to rempve the plaque. A tip i got from a battery gut.
It was an old inverter without a shunt.

I think all the high tech gadgets make us too reliant on percentages. Its a lot more complicated than it needs to be.
Like all the high tech in cars nowadays. There's still a combustion engine in there.

My brother when he was a teenager used a lighter at night to check the battery fluid level on a car battery hydrogen sulfide gas exploded in his face. His face got a bad sun burn his hair was burnt some he was lucky the gas was probably not enough to do more damage. Not sure how his eyes didn't get damaged.

It may go "boom" but doesn't keep burning like LI-Ion.

Glad you are ok. Is this a case of inadequate ventilation when working around lead acid? Or are you indicating that it was well ventilated but the gas in the closed cells ignited?

Thanks for sharing.

What was the make/model of the battery that lasted 20 years?

The lead acid batteries while not preferred worked in your instance the last 20 years. The last set worked 3 years. Failed because of a new self watering feature. So ….

Lead acid is still used in submarines and the Mass is used to help trim them. Think it was argentine sub that went missing while back but doubt we will ever know battery type that exploded in forward compartment. One of the faults noted for that sub was water down the snorkel in which case the snorkel supplies the diesel which is also used to charge batteries which was reported in progress.

Lead Acid still has a very strong preference for Navies in submarines as it is deemed safer….cheaper and the MASS is useful.


The sub that went down was reported as in need of many repairs.




They were running some with other batteries besides traditional lead acid for this class of sub think Korea. Who knows what was in this sub but lead acid still work well. There are a lot more diesel electric subs than average ppl think or know about all around the waters of this planet. Lead acid is not dead.

If all the navies replaced the lead acid in subs would have to add ballast.

The OP batteries as reported by him failed due to his new self watering. Subs — batteries had systems like that too. Think they still check them by hand too. Safety. In which case they say a battery shorted after water came down snorkel of last lost sub report. They say when diesel is running and that happens with snorkel it is ugly - pressure builds up from huge diesel … It being military will never know truth but Lead acid still has favorite apps. Be interesting if it was not lead acid for battery fire. The OP post described spark from volt meter? I use to stick a meter lead directly in each cell to check voltages from cell to cell…with lead acid…for cars.

If volt meter drew serious spark to check voltage would get a new meter. The initial fluke auto meters were banned from DuPont - safety training, railroads and nuclear plants because 1 in million or billion might auto range pop. In ohm or amp setting a meter would spark and meter would be damaged.

Tip if lead acid batteries stink they are gassing and if serious gassing will see smoke. Don’t do anything as it can will explode …. I kept cutter to cut cables which in itself is dangerous. Locomotives we isolated at knife switch let smoke off - cool off.

Working with locomotive we had special meters average volt meters only go up to 1000volts and we needed 1500 volts and later units we built in the amp and volt readings so meters were eliminated for most of those functions. The meter due to high voltage was connected then power applied to get readings….from the main alternators on older units. Shssss I often checked it while run up. Most ppl that blew up their meters had their meter improperly setup EVERY TIME.

Again if lead acid is stinky time to get air…shut down and let it complete the gassing. Wear safety glasses around any battery when doing maintenance… or power off - down for that matter….

Glad you were not hurt. Lifepo apparently have dangers too. Don’t be misled …stored energy is always dangerous.