Does anyone know how much current the starter of a 2.6kw genset might draw?

[Franziska]

Hi,

I have an FME 2600 4stroke generator onboard.
It has an electric starter which I want to connect to my main battery bank.
As the later is constantly charged by a large solar panel I can than leave the remote control switched on.

To calculate the correct cable size I need an idea of how many amps such a starter might typically draw.

Unfortunately I have no means to measure the current and the documents do not specify it either.

Batteries are about 5.5m from the starter away.
Voltage drop permissible about 4% max.
12volt System.

Does anyone have an idea of what current (Amp) it might draw?

Thanks so much,

Franziska

[44'cruisingcat]

Can't help with a direct answer, but if you left the starter battery in the genset, and connected that (in parallel) to your house batteries, the solar would keep it charged too. You could then use smaller cable than would be required if connected direct to the starter.

[smac999]

probably around 100a but that's just a guess. 2awg on a gen is normaly fine. (actually 4% at 30' round trip at 100a actually works out to 2awg)

I don't understand what you mean by leaving the remote control left one.


I wouldn't wire the gen to the house bank. it should ideally be on it's own battery. 2nd choice engine battery.

[skipmac]

Ballpark 100-120 amps. If calculating wire size to be conservative call it 150.

[David M]

There is indeed a way to measure the current. Google a "clamp ammeter".

[smac999]

they are pretty useless for starting. it's too short a duration. even the peak hold ones don't work. becase it's probably like 300a for 1/4 sec followed by 100amp for 3 secs. and meter memory shows 300a.


same with bow thrusters I've measured 1000+ amps with a peak hold ammeter. yet it was going though a 400amp anl fuse. because its so short. actually holding thruster on was under 400a. but it peaks very shortly

[Franziska]

Remote receiver draws constantly small current, want to leave it on.

Idea with charging cable is good. Probably should have a blocking diode in there to prevent issues when the genset is running and charging the small battery too?

Thanks so far.

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[oleman]

Measure the current draw with an appropriate DC ammeter, no reason to guess when the actual solution is at your finger tips.

[hellosailor]

From what I've seen, it is normally accepted for starting motors to pull down the voltage to 10.5 volts under load, way more than a 4% voltage drop. However, I'd suggest that using the heaviest possible cable, to provide the least drop and ensure the best starting power, is a better idea, if you can afford it.


From that point of view it may be enough to simply buy the heaviest cables you can afford, that fit with correct sized lugs on them. And of course also making sure the lugs are properly crimped, which DIY cable lugs often aren't.


Or of course, there are those clamp ammeters, $50 will get you all sorts of "good enough" ones for this purpose. I'd still expect a 4% voltage drop to require heavier cable than you will want to install. Or pay for.

[Franziska]

Gone for the solution with charging the small battery in the Genset via a diode.
Needs only a small current to keep it topped up & only a comparatively small cable.

Thanks for your thoughts.

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[44'cruisingcat]

The diode is a great idea. If you should flatten your house batteries, your genset should still start!