Parasitic draw

[zelmo]

Optimax 200
Model # 1200D73DD
Serial Number 1B044654

I saw in a different board that a Yamaha will draw power when sitting and that power needs to be killed to it to avoid battery drain.

That got me wondering - does an Optimax draw power when sitting?

[Jtreed99]

Mine does. I installed a switch so 1) it wouldn’t draw my battery down during storage and 2) my 3 year old can’t burn up my trim motor.

[Gamblinman]

A properly charged and maintained battery will not be drawn down enough from sitting to not start a properly maintained outboard. You need to look further if you're having problems with battery drain...either the motor has some kind of electrical problem, or some other electrical component on the boat.

[zelmo]

I am not having problems. Just curious about the draw from an Optimax.

[Bob G.]

If you really want to know if you have any parasitic draw on your battery, temporarily connect an ammeter in series with one of the battery cables.

[rvaha]

Better way is clamp on ammeter. Make sure u “0” it out before putting it around the red battery wire

[Rip Bass]

I don’t have any draw on my Opti 200.

[MetalliStratos]

Stereo memory has been the offender for me. I went to a positive shut off and no more dead batts.

[EuropeanAM]

It's not uncommon to see a slight parasitic draw (usually LESS than 800 mah). Often considerably less.

[zelmo]

It's not uncommon to see a slight parasitic draw (usually LESS than 800 mah). Often considerably less.

Thank you. I don’t have a problem but was wondering for when I store the boat over the winter. Based on your answer I don’t need to change what I have been doing.

[Jtreed99]

Thank you. I don’t have a problem but was wondering for when I store the boat over the winter. Based on your answer I don’t need to change what I have been doing.

In my experience I typically have to charge the batteries about every month during long term storage to keep them above 75-80%, at least until I got the cutoff switch.

[OldTimer57]

If you have a 1a draw (1000 ma), it will take less than a week to drop the battery to the point we would call "dead". IF your battery has a 100a capacity, that is 100 hours at 1a draw. If it is a 1/2a (500 ma) draw, then 200 hours (just over a week). So once a month is not going to come close to being enough. If it is a 100ma draw, now you are talking about a month+, but again you do not want to flatten the battery. Also note that a charged battery that is completely disconnected will self-discharge to 50% in about 6 months. So even with no parasitic loss (ie when you have a master disconnect) you will still lose charge over time.

I simply leave mine plugged in 24/7 when not on the water fishing. Have zero problems doing that with a good charger. And good chargers will occasionally overcharge a bit to produce hydrogen gas and stir the acid up to prevent stratification which will hurt the battery over time. Lots of plusses, no negatives... I generally get 5-6 years of life for a battery charged like this, and have for at least 30 years now. Key is a "good charger".

[zelmo]

I simply leave mine plugged in 24/7 when not on the water fishing. Have zero problems doing that with a good charger. Lots of plusses, no negatives

That is not accurate. I have already had a charger fried by a close lightening strike. Others have reported fires in their garage.

I unplug the charger after the battery is completely charged and top off periodically. Knowing that there can be some parasitic draw tells you to be diligent.

[Jtreed99]

If you have a 1a draw (1000 ma), it will take less than a week to drop the battery to the point we would call "dead". IF your battery has a 100a capacity, that is 100 hours at 1a draw. If it is a 1/2a (500 ma) draw, then 200 hours (just over a week). So once a month is not going to come close to being enough. If it is a 100ma draw, now you are talking about a month+, but again you do not want to flatten the battery. Also note that a charged battery that is completely disconnected will self-discharge to 50% in about 6 months. So even with no parasitic loss (ie when you have a master disconnect) you will still lose charge over time.

I simply leave mine plugged in 24/7 when not on the water fishing. Have zero problems doing that with a good charger. And good chargers will occasionally overcharge a bit to produce hydrogen gas and stir the acid up to prevent stratification which will hurt the battery over time. Lots of plusses, no negatives... I generally get 5-6 years of life for a battery charged like this, and have for at least 30 years now. Key is a "good charger".

draw for me was only about 60 mA, (0.06 A). Once a month may “not even be close enough” for you, but I like to unplug my chargers because lightning got one of mine, so there are not “no negatives” of leaving it plugged in. Charger is 15x4 dual pro so it is a good charger. With my once a month schedule I typically charge again the night before a trip but if I forget it still cranks and runs so again, in my experience my draw is low enough and battery big enough, even before the switch install, for once a month to come close to being enough.

[OldTimer57]

Do you NOT have any form of surge protection? We've had lightning strikes very close by. NEVER had anything damaged (except for a couple of surge protectors that saved things). Only fires I have heard about were Lion batteries that have a highly flammable electrolyte in them. Would not use them myself for that reason. I've used a few smaller ones in radio controlled model aircraft / helicopters. I have seen what an overcharge will do. NOT pretty. That's why they have so many warnings about chargers when using them.

As far as 24/7 goes, everyone I know leaves 'em plugged in all the time. None of my "group" has ever had a failure with the chargers plugged in. I have had one serious battery failure while running the T.M. Some sort of internal short blew the top off the battery while on the water, but it didn't hurt anything but the fishing trip since the T.M. didn't have any power to speak of. The chargers are specifically made for 24/7. Yes one can fail, no doubt about it. But by the same token a battery can blow while charging also. It is obviously your boat, and you should do what feels "right". But leaving it plugged in is definitely "accurate". Just ask the manufacturer of your charger.

JT: with 60ma, it will take MANY days to run that battery down to 50%. 50a / .06a = 800+ days. that's the kind of parasitic draw you would like to see. The battery will self-discharge faster than that. Figure 5% per month (and that is a debatable number, some quote higher rates). You are perfectly safe.

[EuropeanAM]

Honestly, there is merit to both sides of the battery charger argument(s). I've seen stuff friend because they WERE plugged in, and I've seen stuff fried because they WERE NOT plugged in.

Consult the manual for YOUR CHARGER, based on the battery type and size you have.

And regardless of which way you go, the battery DOES need to be fully charged when it hits the water.

[OldTimer57]

And just as important, it needs to be fully charged as soon as possible after the boat leaves the water before the lead sulfate begins to crystallize. Once that happens it is VERY difficult to reach full charge again...

Also, as far as lightning goes, in 71 years I have seen exactly one lightning strike that damaged where I Iived. Blew out a TV and VCR. Once.

[Jtreed99]

And just as important, it needs to be fully charged as soon as possible after the boat leaves the water before the lead sulfate begins to crystallize. Once that happens it is VERY difficult to reach full charge again...

Also, as far as lightning goes, in 71 years I have seen exactly one lightning strike that damaged where I Iived. Blew out a TV and VCR. Once.

While I agree that simple surge protection can eliminate all but direct hits, we had two significant lightning hits here in the last year alone and luckily I came out of both better than my neighbors on either side. I grew up 70 miles to the northwest of you OT and we lost heat pumps, stereo equipment, etc., on at least 4 separate occasions in 22 years. Neighbors there had bricks blown off their houses where the power comes in. I guess either I always live on hill or you have lived your life a little better than us.

[zelmo]

As far as 24/7 goes, everyone I know leaves 'em plugged in all the time. None of my "group" has ever had a failure with the chargers plugged in.

And lemmings will follow each other to their death.

And regardless of which way you go, the battery DOES need to be fully charged when it hits the water.

Exactly, which is why you should unplug the charger and put it back on the night before you go out. These smart chargers will turn off after the float period. They do not come back on until the voltage drops below 12.6v. I do not want to start the day with my main battery at 12.61v.

[OldTimer57]

Sorry but the new generation of chargers will NOT let your battery drop to a low voltage. Do you know the difference between a full charge (12.6 volts) and a surface charge that can pass 13 volts? I would guess not. If you take a battery that reads 13.0 volts and let it sit for a couple of hours, that surface charge will dissipate and you are back to the 12.6 volts fully charged state. They go on and off to keep it at an optimal charge level. There are tens of thousands of us "lemmings" that have absolutely no problem with the charger being on 24/7, and for me, I do not get stranded due to a low charge, nor does my boat get burned up because of some mystical fire that might happen once in a million times.

And for the record, the battery needs to be maintained in a state of full charge. If it drops below full charge, that is because the sulfuric acid and combined with the lead, leaving lead sulfate on the battery plates. If it stays for even a day, it starts to crystallize, and once that happens it will not recombine with the water in the cell to turn into sulfuric acid again. This is all pretty easy to verify with some research. As to whether you leave your battery on 24/7 or not, that's a personal decision. I leave mine on because that is what the battery manufacturers suggest and what the charger manufactures suggest is best. I go with the ones that know, not the ones that think they know...