Low Voltage Warning Light & Beeper 2011 DF250

[woods3660]

I own a 2011 Sea Chaser 250 Bay with DX250 for power. The engine has about 140 hours on it.

About two months ago just before a fishing trip I found one of my two original batteries dead. I put the charger on it for about an hour and ran about an hour off shore fishing. Went to start the engine and nothing. Turned the battery switch to all and the engine started.

After returning home on I heard a continuous beeping coming from the helm area while cleaning out the boat. Engine was off and the boat was setting in the driveway. I couldn't pinpoint the beeping so I just turn the battery off and everything went silent. I replace the one dead battery a few weeks later.

Last Sunday I took out some family and friends for an afternoon of boating. Just cruising around in the bay in and out of idle zones. About an hour into the trip I pulled up to an island and dropped the engine to idle speed. All of a sudden I heard this beeping noise and noticed the check engine light was flashing. Then the engine starter to shutter and was dropping cylinders. One of my passengers asked if we'd run aground? I was just about to shut the engine down when the beeping stopped, check engine light went out and the idle performance returned to normal. The engine performed fine on the trip back to the dock.

So here is my question! Based on what I've found in the owners manual the check engine light and beeping was for low battery voltage. Unfortunately, I didn't look at the voltmeter for a reading. Almost everything with a switch was turned on VHF, 2 GSPs, and an AM/FM radio and I was running on one battery. Can someone verify my low voltage theory, why would the engine go into "limp home" mode and should I have replaced both batteries at the same time?

[artdf175]

Think you should replace 2nd battery as well
Being originals and getting 5 to 6 years is just about all one should expect
Low voltage is not necessarily a condition that causes the engine to go into the limp mode but... the ECM does not like voltage fluctuations
So my guess would be the the low and irregular voltage caused by the dead or dying battery was the main culprit
Let's us know what happens after you change out the 2nd battery
Art

[redlowrey]

For the low battery warning to come on while the engine was running indicates you have a problem some where in the system, it would not matter how many devices you had on, the charging current put out by the alternator would far exceed what you were consuming. The engine may have been missing because it was not getting enough secondary voltage to fire the coils properly, you need to do some testing starting with the alternator output, load test the batteries, if you have not got a load tester connect up a volt meter on the batteries one at a time and see what they drop to when you crank the engine, and do some voltage drop tests on the wiring. Check both sides of the sixty and thirty amp fuses.