Optional Outboard Charging Systems??

[Kidmag]

Absolute newbie trying to understand some things.

I'm currently researching small 5-6hp 4 stroke outboards for my sailboat. The boat has a very simple electrical system (interior and running lights, stereo, 5 watt trickle charge solar panel - and soon a tiller pilot) with a 65 ah AGM battery. The trickle charge is great between day sails but will be under manned if I spend more than a day or two on the boat journeying.

Several of the outboards I'm looking at have optional 5 or 6amp alternators that appear to connect directly to your battery.

Couple of questions:

1. Are these worth it / effective? anything else I should know here? For example I just read you can easily blow your alternator by unplugging the charger while the engine in running. Need a power regulator?

2. The battery is near the bow, while the outboard is obviously in the stern. So would it be more effective to run the charger into my electrical panel (which is mid ship) for supporting current electrical needs (potentially, tiller pilot, running lights or stereo)?

3. If I run into my electrical panel, is it as simple as looping it into the positive / negative of the battery loop/connection to the panel?

This all might have seriously exposed my lack of knowledge so go easy.....

Thanks!

 

[alldodge]

Most ALT's will be damaged if the battery is disconnected while its running. Now if power is removed from the excitation leads which power up the ALT this is not an issue. In short if the ALT is powered up, and the battery connection is removed, the voltage spikes and can blow the regulator.

Running only 5 to 6 amps would be easy enough to run to the helm and then the battery, Won't need much for it. DO believe it would be worth the added expense because the tiller pilot will need more current then the standard motor can put out.

 

[Kidmag]

Thanks for the response! When you say "run to the helm and then the battery", do you mean running to the panel? or do you mean running directly to the battery? tks

 

[alldodge]

Run to your breaker panel. With 6 amp charge you need 18 gage wire, going a distance maybe 16 gage. Add in power being used by a device, maybe 14 gage overall

 

[Kidmag]

OK, I purchased a Honda BF5D outboard with the charger kit. Reading the manual now and came across this "the 12v charging system is designed to charge a "starter or cranking" type battery only, it is NOT intended to charge "deep cycle" type battery." WTF? I don't understand why there would be a difference?

 

[dingbat]

OK, I purchased a Honda BF5D outboard with the charger kit. Reading the manual now and came across this "the 12v charging system is designed to charge a "starter or cranking" type battery only, it is NOT intended to charge "deep cycle" type battery." WTF? I don't understand why there would be a difference?

You can charge a deep cycle but the difference is the current needs of each battery.

Easiest way to explain....a starting battery is a one gallon bucket and the deep cycle is a 5 gallon bucket.

You spill a quart of water putting the one gallon bucket in the boat. The five gallon bucket is leaking at the rate of quart an hour.

Both buckets needs to be full by the time you return to the dock so you purchase a one quart per hour pump to refill them.

You go for a 2 hour ride in which pump supplies two quarts of water. You have no problem replenishing the quart lost from the one gallon bucket, but your a quart shy of replenishing the five gallon bucket.

Repeat the process the the next day. How long until the 5 gallon bucket is half empty?

Half empty for too long is suicide....

 

[Lightwin 3]

You can charge a deep cycle but the difference is the current needs of each battery.

Easiest way to explain....a starting battery is a one gallon bucket and the deep cycle is a 5 gallon bucket.

You spill a quart of water putting the one gallon bucket in the boat. The five gallon bucket is leaking at the rate of quart an hour.
.
Both buckets needs to be full by the time you return to the dock so you purchase a one quart per hour pump to refill them.

You go for a 2 hour ride in which pump supplies two quarts of water. You have no problem replenishing the quart lost from the one gallon bucket, but your a quart shy of replenishing the five gallon bucket.

Repeat the process the the next day. How long until the 5 gallon bucket is half empty?

Half empty for too long is suicide....

Good analogy.

In other words, it would take HOURS to top off a deep cycle battery at 5 amps. Deep cycle batteries do not last long if they are left at a partial charge.

Unless you can connect to shore power and charge the deep cycle, you're better off with a standard battery.

The best thing you can do to a deep cycle battery is discharge it all the way and then fully charge it.

 

[Kidmag]

OK - that's a bit of relief. So the charger won't damage the battery from overcharging, or charging at too intense a rate then. My sailboat is on a mooring, and has very basic electronics.

My intention for the outboard charger is really just supplemental in the case where I'm motoring or motor sailing and I'm employing the tiller pilot or lights. Might also hook it up if I know I'm going a decent distance with the motor and will be playing the stereo, charging portables, or using the lights.

Thank you for the responses and explanations.

 

[Kidmag]

BTW - after really looking into this stuff, I realized my battery is a lead acid battery, "starter and deep cycle" is the manufacturer description. Also realizing my trickle charger is likely not replenishing the bi-weekly 4hr stereo use. I'm going to buy a multi-stage charger and bring the battery home to do some maintenance.

Also - my plan is to get a larger solar panel, something like 25-40 watts and a regulator. Then hopefully I can avoid having to take the battery off the boat every 2-3 day sails. Does this sound like a reasonable plan? (sorry, with electronics I feel like I read something, become confident in my knowledge, and then read something else which changes my understanding or makes me realize I don't understand at all..... one day I'll get there )

 

[alldodge]

The solar chargers a nice but most don't live up to expectations. The watt listing is based a full sun, so anything like clouds or other the system is less. Keep a voltmeter with you, and when you go down to use the boat again, measure the battery after it is off the charger for at least 30 minutes.

Lead acid bats should read 12.7V for full charge

 

[Kidmag]

Ok, my battery is a flooded wet acid battery. After charging at home with a 3 stage charger, I waited a few hours and tested it with a multimeter, registering 13.04 volts. Four days later it was at 12.95 volts - without any charging.

 

[alldodge]

You have a good battery,just maybe your meter is a little off (reading high), but is good enough for testing