Over charging on 1984 Force 85 hp.

[maverick974]

I've read the sticky about overcharging problems. New rectifier or voltage regulator? That's my question.
I want to save money but I also want thing right in this boat as I am fishing some pretty big lakes and the last thing I look forward to is getting stuck in the back of some large lake late in the day.
At idle, my guage says about 14 volts. At WOT it is pegged at 18 volts. So far, no boiling or water around the battery but it is a concern of mine.
According to one post, I can buy a new recitifier for just a couple of dollars but a few people said that this may or may not work as rectifiers don't actually "regulate" the voltage to the battery. Or I can pony up and get a voltage regulator.
I'm no electrical engineer hence the question.

What would you folks suggest?????

 

[Frank Acampora]

Re: Over charging on 1984 Force 85 hp.

These are unregulated systems and a new rectifier will not stop the high charging voltage. For that you need a regulator. Lacking that, you can keep the running lights on to help reduce the amount of overcharging.

Now, My go-fast has the same system. I run it for 2 hours and have no battery problems. I suspect that as long as you are not running all day at full throttle and periadically check battery water, you will be OK.

Aside from that, if you do have a battery failure, these engines have a self energising ignition, separate from the charging system. They can be rope started rather easily when warm. You should try it a couple of times to get familiar with the process. Then there is no reason why a battery failure, broken solenoid, or bad starter motor will leave you stuck on the water. Search my past posts for the procedure with pics.

 

[roscoe]

Re: Over charging on 1984 Force 85 hp.

Doubt that you would be running the main motor long enough to cause any damage.

Do you run the motor for hours on end?

If not, don't worry about it.

 

[maverick974]

Re: Over charging on 1984 Force 85 hp.

No, I don't run the motor for long periods. Usually no more than 20 or so minutes at a time, TOPS. At least at speed. I might idle around for periods longer than that but there isn't much of an issue at idle.
So running at WOT and charging that much won't hurt the lights, stereo, fish finders, etc.?

 

[pnwboat]

Re: Over charging on 1984 Force 85 hp.

This is just my personal opinion and I'm certainly no expert in this area, but I believe it's more of a personal preference. These motors have operated for many years without a regulator without any problems. Be aware that the dash gauges can be off a little. To really check it out, measure the voltage at the battery with a digital meter. As long as you are using a standard wet cell dual purpose starting/trolling deep cycle battery, you should be OK. If you are using an AGM, GEL cell battery or one of the special batteries, there may be a problem. Also with the newer electronic accessories available these days, there may be some concern when running some of these devices at a higher voltage, although my Hummingbird GPS depth/fish finder is rated up to 20 volts DC. Having said that, replacing the rectifier with a regulator/rectifier probably won't do any harm. Be aware that you are introducing additional circuitry. Some folks believe that the additional circuitry adds an additional variable which may fail. I have run my 1988 125HP motor for several years with just the rectifier with no problems. Voltage would peak at about 16.5 volts I replaced my rectifier with a later model rectifier/regulator a couple of years ago. Only change that I noticed was that my voltage now peaks at 14.5 volts and my wallet is a little lighter now LOL!

 

[fucawi]

Re: Over charging on 1984 Force 85 hp.

First check the dash gauge is in fact accurate ...your 14 v could in fact be 12 and your 18v only 16 ....that is step one. If it is high and you want a cheap fix you can put one or two diodes in the cable from the rectifier to the battery ..each one will drop it 0.7v use a 10A rated diode from Radio Shack etc ..couple of dollars ....check the true voltage first...!!!

 

[DonNZ]

Re: Over charging on 1984 Force 85 hp.

yes a rectifier will not fix your propblems ,old small output 1-5 amp lowest budget charging systems ran only a rectifier as so small it was hard to damage the battery, yours is likely to be in the 15-25 amp group, check the model specs.
In the meantime Disconnect the charging sytem and run total loss until you sort it.
18 v will defintly charge your battery quickly. Once charged the battery cannot absorb the energy and will heat up eventually make your battery boil and emit large amounts of hydrogen gas, this is highly explosive. I have witnessed a battery exploding, blowing the side out of the battery case with acid too. You'll have a hard job getting the missus into the thong !
not a good look over the kids either.
until you can afford to fix it buy beg or borrow a 'regulated' battery charger 5 amp is enough. Charge it up on your return form boating. not before you go, as sitting flat is the killer for a flooded lead acid.

Regards Don

 

[Frank Acampora]

Re: Over charging on 1984 Force 85 hp.

Let's not use scare tactics, gloom and doom, and war stories on him! His engine delivers about 7 amps MAX and the likelihood of him blowing up a battery is about as good as getting hit by lightning. Unless he thinks it is a good idea to have a lit cigarette back by the battery/fuel tank compartment.

In reality, he should be able to run his engine as is for years until the battery has reached the end of its useful life with no problems. If a regulator sets his mind at ease--then by all means he should buy and install one. Otherwise, there is no real advantage.

 

[fucawi]

Re: Over charging on 1984 Force 85 hp.

find out the true voltage ..!!!! Batteries gas they dont boil ,,using a lot of distilled water means it its over charging

 

[maverick974]

Re: Over charging on 1984 Force 85 hp.

It's been like this for a couple of years now so I'm not overly concerned about it. I just moved from a small coastal Oregon town where the lakes were very small so I never gave it much thought but I now reside in Mesa Arizona. The lakes here are huge by comparison and hence the concern since I have the big motor on so much longer duration.
I haven't checked out the guage yet either. Next on my list.
I thought I read in a manual somewhere that my charging system was 16 amps but I'm not certain. How would I find out?
It's a 1984 Force. 85 hp.

 

[pnwboat]

Re: Over charging on 1984 Force 85 hp.

According to the Clymer manual, the 1984 85HP has a 7AMP @ 3500RPM charging system. The 1996 and later motors with the Mercury Thunderbolt CDM ignition systems have a 14AMP @ 3000RPM charging system.

 

[roscoe]

Re: Over charging on 1984 Force 85 hp.

Like Frank said, 7 amps.

Only one Force motor ever put out 16 amps, and that was a mid 90's 150 hp.

 

[maverick974]

Re: Over charging on 1984 Force 85 hp.

Then for me, that's the definitive answer. 7 amps. Doesn't sound like much but I've never had to charge the starter battery in the 4 years I've owned it.

 

[DonNZ]

Re: Over charging on 1984 Force 85 hp.

"I've never had to charge the starter battery in the 4 years I've owned it."

That is what really matters !!


7amps x 18volts = 126 watt into the battery minus nav lights.

I've observed a house battery at 50 deg C sounding like a jug of rolling boiling water due to over voltage.


Regards Don

 

[maverick974]

Re: Over charging on 1984 Force 85 hp.

"I've never had to charge the starter battery in the 4 years I've owned it."

That's is what really matters !!


7amps x 18volts = 126 watt into the battery minus nav lights.

I've observed a house battery at 50 deg C sounding like a jug of rolling boiling water due to over voltage.


Regards Don

Well, as far as I know, it has never boiled. I've only had to add water once about 3 weeks ago. Just a little in each cell. I haven't noticed any water around the batteries or in the compartment so far either.
I'll keep an eye on it.

 

[DonNZ]

Re: Over charging on 1984 Force 85 hp.

Maybe as mentioned your running loads are countering the excess charge.
18 volts is not a good look at all. I'd not be turning electronics on at 18v as the 18v your digital meter reads may be a average not peak.

By topping up the electrolyte you are maintaining your battery, You'll know overcharging as it'll smell just like rotton bananas and spit corrosive electrolyte. This is called it's rate of emisivity proportional to state of charge, temperature and charge rate.
If you wanted it sorted It's a 2 coffee job, not so difficult, maybe couple of hours.

Confirm your engine is 7 amp.
A 20 amp regulator / rectifier is prob $100, check out w..transpo as a place to start.

2 or 3 ac wires to charge coil
one to positive of battery ( via a 20 amp fuse )
one to ground
sometimes they get flash and provide a warning light output, I prob wouldn't bother. you'll know by your cranking speed and electrolyte top up.
I'd mount it on the engine to reduce radiated noise so your vhf. fish finder and sound sytem has less noise to contend with.

Regards Don

 

[Jiggz]

Re: Over charging on 1984 Force 85 hp.

Well, as far as I know, it has never boiled. I've only had to add water once about 3 weeks ago. Just a little in each cell. I haven't noticed any water around the batteries or in the compartment so far either.
I'll keep an eye on it.

You're doing OK. If the system has lasted this long without "killing" the battery, you're obviously OK. If in the future you'll need to replace the rectifier, then you might as well go for a rectifier/regulator which cost just about the same and involves the same amount of work. As for the mumbo-jumbo terms about battery boil over, voltage peaks, averages and RMS, proportion of state of charge with temperatures and charge rate, just save your dictionary and wait until rectifier replacement is in order.