non voltage regulated outboard

[mickab]

hi all, just wanted to post a little helpful tip from my experience. if seen post on here talking about non voltage regulated outboards over charging and burning up sealed batteries. yes the battery acts like the regulator so with that in mind i run a optima yellow top battery as my cranking battery, which also runs my electronics. what i have found is if i charge this battery completely on the charger ill have reading of over 16 volt while im running the motor, but if i only charge it to about 80% i have zero issues. voltage never goes over 13.5 volts. as i fish bass tournaments every weekend ive had a lot of time to test my theory. but a good deep cycle with a lot of cold cranking amps is i think the key. i hope this helps my fellow mercury / mariner owners out their running this style of charging system.

 

[Texasmark]

Re: non voltage regulated outboard

Most chargers have a voltage x current window in which they operate. It's the way they are designed. When you fully charge your batteries prior to departing, the load (current requirement) on the engine alternator is light so the voltage is high. Conversely the opposite is true and as the battery fills, the current drops off and the voltage continues to rise.

My limited experience with non-regulated power supplies is that they are light weight chargers so that they don't have the capacity to put out a lot of wattage and burn things up. Course if you were on a long cruise with no electronics sucking on your electrical system then you might boil some water out of your battery if it is of the old style that required maintenance; never overcharged a maint free battery so don't know about them.

Your electronic equip. probably doesn't (boom boxes excepted, etc) require a lot of current and maybe no internal regulator so over voltage could cause erratic readings.

Mark

 

[buzzm19]

Re: non voltage regulated outboard

Guys, my experience was the same, my volt gauge was showing above 16v when running above idle (1978-115-l6). Thank god for Iboats, after a lot of research I found out that the older mercs with no voltage regulator must use the acid type battery as it creates a resistance to keep the voltage down. When I switched from the jell battery to the old type acid battery my volt problem went away. That is my experience, the other option was to install an aftermarket volt regulator. Buz