Battery Ruptured During Emergency Generator No Load Testing (PM)

The batteries seem to have been damaged, or poorly maintained.....The explosion suggests the presence of hydrogen in an arcing environment, this could be due to overcharging the batteries, and low fluid condition....The arcing possibly bad or loose battery cable connection...The charger could be defective or possibly set wrong(ie: providing an excess amount of maintenance charge amps)

My thought also

I am a little confused by the information here. At the end of your question, you indicate that the Manufacturers requirement is 1800 Amps (at 32°F). Yet at the beginning, you indicate that the generator comes with 4 of these batteries.

From the specification, it appears that the short circuit current rating is 950 Amps per battery. And since it would take at least two of these to provide 1800 Amps, I suppose each battery is 12 volts? This would then require a parallel connection of two batteries in series, yes? Because any conclusions would require knowledge of how these are connected, it would be important to know this first.

In general, however, the ruptured batteries were most likely caused by combustion of hydrogen gas inside the battery. Your lead acid type batteries are subject to this, especially during periods of extreme load.

And your connections to achieve a current of 1800 Amps would have to be perfect with a very large cable from the battery to the starter motor or VFD.

I would expect that the interruption of such a large current would also have a large emf pulse that could fry either the battery charger or ignite the hydrogen gas in the battery. From an engineering point of view, it seems that the battery start system is poorly designed and could only provide enough energy for one or two starts per day.

As for the battery charger, (really a trickle charger) it also seems to be undersized for emergency conditions. I'll be watching this one for other peoples replies. It seems to me that the Cummins vendor has some explaining to do.

Did the Cummins dude check the charger when he replaced the batteries?

We have check the engine starting circuit and also engages local Cummins dealer to help

to trouble shooting, do not found any unusually at the engine starting circuit.

After the dealer install 4 number of "Yellow top "battery, and start the engine for five

to six time and don't facing any difficulty to starting up the engine at all.

The "Yellow top "battery replacement is a temporary solution, because the production

process can not allow to have any power outage .

we are waiting for the battery OEM faille analysis report before we make any modifier to

the engine starting system.

OK. That's the starting side checked.

What about the charging?

The starting battery (Maintenace free battery) is charge by the "DSE0907" 24V industry 5 amp charger and continuous 24/7 non stop charging, and only the flat charge is be connected and the boot charge is disconnect from the system.

Once the engine started up and disconnect drive will disconnect (change over) the AC charging system to engine alternator charging system.

Our 1000KVA emergency Cummins generator is located at enclosure (Cantina) without any air condition system and the starting battery is right insider engine compartment , Once the engine is running the 3 number exhaust fan will automatic cut in to exhaust all the exhaust gas generate by the engine.