Notes on using a single battery

[seahouse]

seahouse wrote:
Magnetos. Your lawnmower has no battery and yet starts.

Russ wrote:
Yea, but my lawnmower doesn't have a complicated computerized fuel injection, oil injection and ignition system. Those etecs have some fairly sophisticated electronics onboard.

If the thing will start without any power whatsoever, that's pretty cool.

You are right Russ. I don't think it's too unusual to be able to rope start an outboard with a dead battery. But to rope start a technically advanced outboard like the E-tec might be considered more remarkable. The technical advances do make it easier to start than it would otherwise be, though.

Magnetos are common on outboards (and motorcycles, lawnmowers etc), they simply use permanent magnets (instead of field coils of a regular alternator that would consume power for energizing) so with just the hand spinning of the flywheel they provide all the (AC) juice needed for startup. Once running they provide all the power needed to run everything else and charge the batteries.

Airplanes commonly use such a system, you can start and run them independently of the battery by swinging the prop.

Matt --I'd like to see someone trying to rope start a motor that's tilted up, though; it could potentially be entertaining (as long as no one innocent got hurt).

You could test your (and my) theory easily by briefly tilting the motor up when it's running (idle, neutral). I suspect that it will stop running at some point when tilted up, but don't know for sure. My boat's on the hard and fogged for the season so I can't find out myself.

-B.

[kadet]

As for dead battery with the motor up, just pull start the motor in the up position and then lower it running. The ETEC can run for up to 15 minutes without cycling water. You would want to be pulling it from the side, maybe with a block attached.

Actually this is what I was warning about.
This maybe so but the time it takes to lower the motor while it is running can and does seriously damage the plastic impeller in the water pump as it is spinning un-lubricated by water as it drains from the pump when tilted. Please don't ask me how I know this

Yes the E-TECs can and are easy to hand start. Getting the cowling and other crap off is not. I have a single battery and now just carry an auto jump starter as a backup. Much easier than hand starting or rigging a second battery.

[Catigale]

I've run my Merc without water accidentally for 15 minutes. No damage. If a motor won't idle without croaking Sans water for some reasonable time, I wouldnt want in salt water or near shore

[kadet]

I've run my Merc without water accidentally for 15 minutes. No damage. If a motor won't idle without croaking Sans water for some reasonable time, I wouldnt want in salt water or near shore

Did you pull the water pump apart and inspect the impeller? Mercs are no different to any other outboard they use a plastic impeller and as little as 60 seconds without water can start to melt the blades. The fishing forums are full of stories of woe of people running Mercs without water and stuffing their impellers.

[raycarlson]

why would anyone even want to consider pull starting a motor when fully tilted up. Have never seen a T/T unit that doesn't have a manual release screw on the cylinder somewhere.

[seahouse]

why would anyone even want to consider pull starting a motor when fully tilted up. Have never seen a T/T unit that doesn't have a manual release screw on the cylinder somewhere.

I would suppose scenarios like; where a screwdriver were not available to loosen the screw; the water is too angry to let you safely hang off the back of the transom to do it; or just the lack of awareness that such a screw even exists. It's somewhat of a risky manoeuvre for even the most agile person- you then have to get out of the way of the now lowering unit because it descends right over the area where the screw is located.

[Russ]

why would anyone even want to consider pull starting a motor when fully tilted up. Have never seen a T/T unit that doesn't have a manual release screw on the cylinder somewhere.

I would suppose scenarios like; where a screwdriver were not available to loosen the screw; the water is too angry to let you safely hang off the back of the transom to do it; or just the lack of awareness that such a screw even exists. It's somewhat of a risky manoeuvre for even the most agile person- you then have to get out of the way of the now lowering unit because it descends right over the area where the screw is located.

I'm sure my Suzuki has such a manual release, but I have no idea where it is and certainly don't want to hang over the side to locate it.

--Russ

[Kittiwake]

.... I have a single battery and now just carry an auto jump starter as a backup. Much easier than hand starting or rigging a second battery.

Agreed. We have used an Eliminator 700 amp mobile battery pack for 3-4 years now for this purpose. Only needed it once (when the battery ground terminal was loose). The rest of the time it serves as a great source to recharge onboard electronics via USB port or cigarette lighter attachment. I usually bring it home to make sure it is fully charged after sitting for a long time, but while out on long trips one can top it up with a cigarette lighter fitting to the main battery.

[DaveB]

Took me 15 tries and 230 lb weight with all my weight behind it to get a full turn on the rope to start my bf50hp Honda.
I have twin 29 group deep cycles for house and one group 24 deep cycle for starter. 2 45watt solar panels and a 63 quart refig./freezer.
Works great for me. I do have a Diode separating House from Starter battery.
I have had tiller raymarine St1000 Autopilot and it only drew 1 amp or less.
4amps a hour on autopilot is unexceptable. My frig. draws average 2.5 amps in 90 degree temps.
Dave

So I actually did test rope starting this about six months after we bought the boat with the battery disconnected (I say test, I mean I left the boat powered on for a month on the trailer and killed the battery dead dead).

The hardest part was figuring out how to remove the cowling over the flywheel to get the rope on. Okay, I'll admit that I didn't even know I was looking at a cowling, and had to google what to do because I'd never rope started a motor before. I did one rather tentative (read wimpy) first pull, which didn't work, and then got my feet situated on the motor well, wound the rope up good, pulled it, it started, and I banged my head back into the wheel something nice.

I'm nice and fat, so I bring a lot of inertial mass to the motor starting problem. If it were ever a problem, I'd tie a bowline in the bitter end of my mainsheet, loop the pull cord handle through that, hang the mainsheet top block from the mast carrier arch, and tie a loop to the bottom block. Then stepping full weight onto the loop in the bottom block will pull the cord with a 4x advantage in speed and torque of 1/4 of your body weight. Should work pretty well.

But the ETEC fires right up. The generator on the thing is actually permanent magnets on the flywheel with a wire coil around the entire thing, so it's not a separate, visible unit like you'd normally see in a motor. According to their technical documents, the motor is generating 30V by 1/3 rotation and at that point the EMM is booted and ready to go. Apparently the generator naturally creates 54V, and the EMM controls exactly how much charging power it provides. I'd love to see a hack that lets idle speed in neutral throttle up to develop the full 27 charging amps when not moving, because I bet this thing would be competitive with a generator in terms of overall efficiency.

According to their docs, it generates 10 amps at 1000rpm, but I measured 12. Huh.

This is my first outboard motor, so I'm no expert it what makes an outboard good. But I can't imagine being happier with a motor. If I had one complaint, it's that it does drink a bit more oil than I expected. Fortunately I'm not paying for XD-100 because it only lasts 50% longer but costs 100% more.

As for dead battery with the motor up, just pull start the motor in the up position and then lower it running. The ETEC can run for up to 15 minutes without cycling water. You would want to be pulling it from the side, maybe with a block attached.

http://continuouswave.com/whaler/refere ... _e-tec.pdf

Another thing I noticed on this trip however: At 5..7 knots, there's enough aerodynamic backdraft and not enough forward wind behind the boat that the exhaust, including CO, blows into the cockpit under the helm seat. I'm easily annoyed by smells, so I draped a wet towel over the gap under the seat and set the helm seat back down over it which solved the problem. I'll be making a sunbrella cover for the area below the helm seat that I can snap in place to permanently fix the issue.

[Boblee]

There a lot of reasons why a battery will go flat, I suspected our house and start battery's might have been sick (8yr old) so took a spare 840 ah battery but could just as easily have carried one of the jumpstart packs, eventually I didn't think the house battery was producing what it should but was drawing plenty, then found it was almost ready to explode.

My frig. draws average 2.5 amps in 90 degree temps.
Dave

Thats a bit like fuel consumption or how long is a piece of string and see the manufacturers using figures like this but even though you give the ambient temp you need to consider setting, temp of food going in, door opening and temp inside boat night and day etc, if running a fridge you need a spare battery but even at the low figure quoted thats 50 amps and to put 50amps back in you need to send at least 65 amps to the battery but to charge it fully ie float charge it will take a lot of hours depending on the charger rating.

[mastreb]

Hey Dave,

I estimated 4 amps, it's not a measurement, so don't take that as all that meaningful. I'd have to do a little re-wiring to actually test it.

Matt

[kurz]

Took me 15 tries and 230 lb weight with all my weight behind it to get a full turn on the rope to start my bf50hp Honda.
ery dead dead).

Hello
Did you try to make a long rope and stay down in the cabin? So you have a good angle with the start rope to the outboard, and have a good position, can put your leg on the leather. Try it out - it will work for shure at the second try!

[Boblee]

Hello
Did you try to make a long rope and stay down in the cabin? So you have a good angle with the start rope to the outboard, and have a good position, can put your leg on the leather. Try it out - it will work for shure at the second try!

With respect pull starting your motor is not something I think we should be suggesting that is easy in any situation but do think it should be tried under good conditions so you have an idea what is involved and the wires strapped to the cowling should be made ready for easy removal when it is essential to start it this way.
Normally we carry a portable 50 amp dc genny which can get us running in a few minutes but on the one time I needed it, it wasn't packed and we needed to get out into open water for an 80k run with the tide, we were also low on mixing oil as I was waiting for a mate to bring some from Darwin 8-900k's away which was the only stockist in the centre of Aust so wanted to stay around 2000rpm to conserve it.
Waiting for the panels to charge was only an emergency/temp option.

[seahouse]

we were also low on mixing oil as I was waiting for a mate to bring some from Darwin 8-900k's away which was the only stockist in the centre of Aust so wanted to stay around 2000rpm to conserve it.

Hey Bob-- I assume you were counting that when the oil light on the E-tec goes on you have about another 5 hours run time (or more with XD-100) or about 1/4 of the tank left as reserve? Even knowing that, it still can be nerve-wracking running with that red light on.

And "apparently" the E-tec will also run another 5 hours after that (after the reservoir has emptied), but I haven't independantly confirmed that (I read it on the internet), but expect it's intended for an "emergency" and I wouldn't count on it anyway.

But I do know for a fact that some cars (aluminum V-8s) were engineered to be capable, over ten years ago, of running for several hundred miles with no coolant in them, without harm; and did so. (They fired on alternate cylinders to control heat build-up, etc). So the 5 hours without oil (well, there would be some oil) on an engine with such fastidious computer control over operating parameters, over ten years after that, doesn't seem like too much of a stretch.

-B.

[Catigale]

I've taken my battery down to "won't turn the starter" level and still pull started the Merc BF 50 in two tries, very easy.

Computer and fuel pump need about 7 volts to work, you really have to kill a lead SCID battery to get it down that far.