1ea. start and house bat or 2 house batteries?

[1st Sail]

Time to replace batteries. I currently have 2 AGM group 34, 1 starting, 1 house, with a combiner. Considering my Etec barely turns over before it starts I'm thinking of going with 2 house batteries for the future. Granted start batteries are designed for high current loads during starting. The Etec virtually never cranks. Touch the key and it's up and running. Also Etec's have relatively low starting current draw. Worse case I could switch the combiner to 2 batteries for starting in the event I have a situation that requires a longer starting/cranking period then normal.

Comments would be appreciated.

[Bayou]

I'm in the same boat... No pun intended. I'm thinking of just using 2 optima dual purpose group 34 for house and starting. I used them before and had good results.

[March]

Yeah, there have been numerous debates on that point. The jury is still out deliberating. In theory, even one battery would work, as long as you have a portable battery package for emergency startup. Or two separate batteries. Or smaller, 6-volt batteries in series. Or three combined. Or not. So many options...

But since you already have the battery cables in place, why not take out the older batteries, haul them to Autozone or some equivalent store, have them check the batteries for free, replace the bad one with one of similar size, and keep on keeping on.

(At least, that's what I did...)

[Tomfoolery]

I've never used a 'start' battery. Only deep-cycle house batts, and usually just one. My Honda BF50 will crank fast and for long periods, even on the old battery. My last boat had a diesel IB, and I only used house batts for that.

Start batteries are designed for high current for short duration, but don't tolerate discharge much below 10% (or so I've often read). Marine deep cycle batts can't generate as much current, but the puny OB engines don't need much anyway. They're more like motorcycle or very small car engines, which use small batteries.

I'd rather have the deep cycle capability that will be used over high current output capability that won't (can't, really) be used, as you sacrifice one for the other due to the construction of the plates inside the battery.

Best of all would be real 6V deep cycle golf cart/forklift type batteries in series, but I've never gone wanting with one house battery being used at a time with one in reserve, and either a charge relay (best), or a dual-output charger (next best), with 1/2/Both/Off switch. And if your needs are modest, a pair of deep cycle 6V batts in series, and a portable start booster pack for backup.

And a pull-starting rope for the OB, for real emergencies.

[Bayou]

One other thing that we do is carry a small harbor freight 900 Watt generator for the last 2 years in case we have to recharge the batteries, however it hasn't been used for that purpose yet only used at night for Xtra lighting for night fishing

[1st Sail]

Election results are in. I'm going with two deep cycle house batteries. My Excide AGM marine group 34's start & deep cycle are done after 11 yrs. No complaints. I keep them on a maintainer year around and store the boat in my heated warehouse. I'm sure that contributed to the long life.

Time for reelection again:
Excide again, or Optima, etc.?

I never leave the combiner set to 2 while under power. Under power the Perko is set to 1 or 2 so the batteries are charged individually. Future plans are to add solar & a battery system monitor.

Next up is a battery monitor, charge controller for 2 batteries compatible/expandable with a solar power system.
Xantrex? Etc.

[Tomfoolery]

I never leave the combiner set to 2 while under power. Under power the Perko is set to 1 or 2 so the batteries are charged individually. Future plans are to add solar & a battery system monitor.

I do essentially the same thing, alternating between 1 and 2 for each day sail excursion. My charger has two independent circuits, so one goes to each battery, and I leave the charger powered at the dock so both are maintained at full charge. Alternating between batteries also will give me a little early warning if one is getting weak, while the other is kept as a backup.

[March]

I have an old Xantrex Pathmaker combiner for three batteries (initially for two, but it crapped out on me after a few good years, so I upgraded to three). They don't make them any longer.

It seems to be working fine, switching automatically from one battery to the other, either under engine power or solar power, as need may be. Have to confess that I am not 100% sold; sometimes, at night, the combiner which is supposed to work as an isolator too, separating the batteries and keeping the engine one full, doesn't seem to be doing its job right; the engine battery is only 60% full in the morning, along with the house batteries which power the cooler overnight. It may well be that the engine battery is old and doesn't hold charge, or something else (like the gauge that measures how full each battery is in percentages) However, i thas never let me down dead cold: there's always enough power to start the engine in the morning and a couple of hours on the panels (160W) reload the batteries anyways, so I don't worry too much about it. Only occasionally.

If I were to redo the system from scratch, I would probably find a different combiner. Xantrex doesn't make Pathmakers anymore, but I haven't researched the replacements, so I can't tell.

[Mac26Mpaul]

I'v never had a start battery in the boat in the 7 years I'v had it. I have 2 x 105a/h duel purpose (start/house) batteries in parallel which fit perfectly in the M battery compartment. Very simple and easily handles all our power needs including running the fridge, the kids watching a movie or two at night, charging all manner of stuff, (cameras, drones, laptops etc.)
These batteries have a good name here, might not be available there, but I'm sure there is something similar
http://cometbattery.com.au/shop/search- ... l-purpose/

Heres a bit of a video of my solar setup which shows the batteries in place
https://www.youtube.com/watch?v=lzdVypTGmk0

When going away, I sometimes remember to take the generator as backup, but otherwise, if something happens to the batteries, I figure I can work out how to use the ETECs pull start capability.

[Tomfoolery]

. . . if something happens to the batteries, I figure I can work out how to use the ETECs pull start capability.

That's something I mention, like above, but have never tried. I really ought to fix up a pull rope with tee-handle, and give it a go. In the driveway, as I have to remove the plastic flywheel cover, and it's probably a bit easier to do when spring commissioning rather than on the water, at least for a first try.

Just added it to my spring to-do list.

[Russ]

The etec is amazing that way. It can be pull started with a dead flat battery.
I have no idea how difficult it is to do.

These outboards will start with a lawnmower battery. We're not cranking big V8 diesels so deep cycle makes more sense.

[Mac26Mpaul]

A few years back with my old batteries, I drained them flat and the motor wouldn't start. I thought I was going to have to learn how to pull start it and dug out the rope and wooden toggle (which came with my Etec). I then messed around for about 45 minutes trying to find how to do it in the manual etc. Only then I thought I'd it one more try with the key, and sure enough, she started first go. The solar panel had put just enough juice back in.

Here is a helpful vid on pull starting them
https://www.youtube.com/watch?v=N7ktbyRb02g

[kadet]

Although the Etec can be rope started it is a PITA especially in a emergency, the flywheel cover has to be removed and there is bunch of connectors at the back of the cover that need to be unhooked, not too bad I suppose on a stink boat that has been at anchor all day fishing but on sailboat that has just dropped sails heading into a narrow channel . Try doing that in a chop hanging out the back of the

I just carry a lithium car jump starter much easier, in an emergency I think I could have the thing on the battery under the ladder in about 30 seconds

1 Bank of batteries is much easier to wire, charge and maintain if 2 identical batteries are used.

[dlandersson]

Yeah, I have two marine batteries from Wal-mart PLUS (and I hope I never need it) a "jump starter" for an emregencies PLUS I've gone thru the pull start process on my 50 HP Merc.

https://www.amazon.com/NOCO-GB20-UltraS ... B015TKPT1A

[Sumner]

2 Trojan T-105 6 volt batteries in series with a single on/off switch. More amp/hrs for the buck. Are "true" deep cycle batteries and will last longer since they can be pulled down further without the same damage. Will charge more efficiently than 2 12 volt batteries in parallel. Will charge much better than two 12 volt batteries where you use one and then the other. Will also last longer since you aren't pulling them down as far.

Only negative is if by some strange chance you run them down you will now wish you had a lithium 'start' battery as mentioned above. They will easily start your outboard. People start much larger diesels all the time with them,

Sumner

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