battery discharge during long trolling periods

[russ keller]

I have an 2004 Mercury 90 ELPTO. The battery discharges during long periods of trolling. Trolling RPM (idle under load), is 800 and shows battery volts (12V) at the battery with my Simpson 260. Dash guage reads 10V.
At 1000 RPM I read 12.6V at battery and don't reach 13V untill 1400 RPM.
The local dealer says that battery discharge at Idle is normal for this model and there's no fix. Is this true? Is there a fix?

 

[j_martin]

Re: battery discharge during long trolling periods

At the price of fuel, I would think you'd be motivated to get a low hp kicker for trolling.

I've seen a fin sorta doo-flapper thingie that bolts to the cav plate, lays out flat and does nothing when you're underway, and folds down behind the prop spoiling the flow so you can back troll slowly with the engine revved up a bit.

That's my story, and I'm stickin' to it.

hope it helps
John

 

[DRIFTER_016]

Re: battery discharge during long trolling periods

I have an 2004 Mercury 90 ELPTO. The battery discharges during long periods of trolling. Trolling RPM (idle under load), is 800 and shows battery volts (12V) at the battery with my Simpson 260. Dash guage reads 10V.
At 1000 RPM I read 12.6V at battery and don't reach 13V untill 1400 RPM.
The local dealer says that battery discharge at Idle is normal for this model and there's no fix. Is this true? Is there a fix?

My '91 90 Merc is the same, I don't woory about it as I have 3 batteries and can hook up to one of my trolling motor batteries if needed.

You can use a trolling plate as suggested which will increase your rpm and charging capacity at trolling speed.