Low Voltage Alarm on COLD start

[thommo59]

I'm pretty sure it's been asked before, so my apologies.

2017 Mercury 200hp Pro XS Opti 2B524152

This alarm goes for maybe 3-4 seconds on the first cold start of the day only, after that, perfect. This has happened pretty well since new but lately maybe a tiny longer on the alarm. It's only cold first start.
I have put in a new battery, charged fully before each outing 1000CCA RC180 MCA 1200 100AH but no change. Have checked all connections and battery connections are stacked correctly. Have checked isolation switch connections along with starter motor and solenoid connections. Charging system is running fine and showing on Vesell View when running. Battery Voltage with no load when charged is 12.9v.

Why only on that first start?, the colder the day the worse it is. If I start it, run for a 2 or 3 minutes, stop and start again, no problems at all.

[lpugh]

I'm pretty sure it's been asked before, so my apologies.

2017 Mercury 200hp Pro XS Opti

This alarm goes for maybe 3-4 seconds on the first cold start of the day only, after that, perfect. This has happened pretty well since new but lately maybe a tiny longer on the alarm. It's only cold first start.
I have put in a new battery, charged fully before each outing 1000CCA RC180 MCA 1200 100AH but no change. Have checked all connections and battery connections are stacked correctly. Have checked isolation switch connections along with starter motor and solenoid connections. Charging system is running fine and showing on Vesell View when running. Battery Voltage with no load when charged is 12.9v.

Why only on that first start?, the colder the day the worse it is. If I start it, run for a 2 or 3 minutes, stop and start again, no problems at all.

BY pass that switch, bet the problem goes away

[EuropeanAM]

Please take a moment to review the Announcements at the top of the Forum, and be sure to provide the REQUIRED info (serial number) when posting. Thanks!

Agreed- connect engine directly to cranking battery (preferably with clamp-on terminals as suggested in the "Batteries" post from the FAQ).

[thommo59]

Please take a moment to review the Announcements at the top of the Forum, and be sure to provide the REQUIRED info (serial number) when posting. Thanks!

Agreed- connect engine directly to cranking battery (preferably with clamp-on terminals as suggested in the "Batteries" post from the FAQ).

Apologies Don, meant to do that in the original post, it's there now. I guess the feeling is even with clean connections at the master battery switch, the actual internals of the switch are not carrying the full current under cranking power?

And I already have clamp on terminals on the battery, have also tried direct to the studs on the battery.

[thommo59]

Well I by passed the battery switch and went straight to the battery. Did a test start but just using the flusher and 99% improvement. This weekend is the test at 5am in the morning and it’s mid winter here. I’ll report back again after that and if all good, is it just a case of a new switch?

[Dan21XRS]

I'm watching this thread... I've got a cold-hearted Opti 250 that acts the exact same way... I've had the battery load tested and they say it's in tip top shape... Dan

[SilverFox579]

Battery switch needs to have equal or greater cranking rating as required by engine.

[thommo59]

Well, tested today with the switch by passed and perfect now. The switch that came on my 2018 Triton just doesn’t cut it. I just ordered a new one 1500amps for 10 secs at 12volts

[Savage]

Well, tested today with the switch by passed and perfect now. The switch that came on my 2018 Triton just doesn’t cut it. I just ordered a new one 1500amps for 10 secs at 12volts

This is why I don't use a master cut-off switch on the START Battery.

I do use a switched breaker on the trolling motor batteries.
I do have ALL of my ELECTRONICS running through a separate fuse panel, which has its main power controlled by a relay.

[SilverFox579]

This is why I don't use a master cut-off switch on the START Battery.

I do use a switched breaker on the trolling motor batteries.
I do have ALL of my ELECTRONICS running through a separate fuse panel, which has its main power controlled by a relay.

Exactly how mine is wired too.

Upside for folks using battery switches, at least with Blue Sea Systems, you can no longer buy a traditional battery switch with a cranking rating less than 900A. Neither Marinco nor Perko provide a cranking rating for their switches, just continuous and intermittent.

[06 SB]

This is why I don't use a master cut-off switch on the START Battery.

I do use a switched breaker on the trolling motor batteries.
I do have ALL of my ELECTRONICS running through a separate fuse panel, which has its main power controlled by a relay.

Great minds think alike. I set up mine this way too.

[thommo59]

Well I can confirm this was caused by the battery isolator switch. I replaced it with a Narva 1500 amp rated switch and today was the test. 5am, mid winter here and it’s perfect now.
Thanks Leon Pugh