I've got a solar charge controller, with option to wire it up to suit a conventional wet cell battery, or a sealed "no maintenance"battery. The battery I've got is "semi-sealed" ("low maintenance") type.Should I treat that as a sealed type, or a conventional wet cell type! "PWM setpoint" spec is 14.3V for sealed type, 14.8V for wet cell type.
mechnificent,
Dec 21, 4:51pm
i'd set it to the wet type. 14.3 will be bad for the battery in the long run. Mostsolar regulators cycle the battery to a slightly higher than normal voltage every so often, once a month or after the battery has been beow a certain voltage. The batteries need the high voltage cycle to prevent sulfation due to the use they get.
mm12345,
Dec 21, 7:16pm
Thanks.All looks good.With full sun on the panel, voltage at the battery peaks and holds at 14.78V.I looked at some panels with inbuilt charge regulators, but as I need to run about 4m of cable, it seemed to make sense to me to position the controller on the battery box, to avoid voltage drop between the controller and battery. The charge controller (6A) also has a 6A 12v regulated supply out.I'm not using it, as I suspect my VHF on full transmit power probably draws close to that, and if anything else like nav lights, stereo or cabin lights are on, then it will kill the regulator.The small inverter I've got is rated 10-15V. There's a possibility (probability I expect) that the charge circuit from the outboard motor is unregulated.There's a heat-sinked "thing" connected up in the motor, but I suspect that's just a bridge rectifier, not a regulator.I can't test it right now, as the damned motor is in pieces in my garage - waiting for parts to arrive.I don't think there's an easy way to regulate the output, as the 6A (at peak revs) charge circuit connects directly to the battery cables used for the electric starter.It hasn't caused problems (killing batteries) in the past, but the motor is usually only running for an hour or so max. A small 10W unregulated solar panel did seem to kill batteries.
pup2,
Dec 21, 8:01pm
Wondering, why would 14.3v be harmful in the long run!
mechnificent,
Dec 22, 3:15am
Solar panels are often connected to power systems where the batteries are run low during bad weather, then the batteries get a condition called sulfation on the plates. To get rid of the sulfation you over charge them slightly for a short time, then cut the voltage back to the normal full charge level. If you don't do the de-sulfting process, the batteries slowly loose their capacity and start behaving like a much smaller battery than they actually are.
mm12345,
Dec 22, 3:27am
I'm wondering that too.I would have thought the problem would be that if the battery was a sealed calcium type, then 14.8v may have been a problem.
I reassembled the outboard engine this evening, so while I tank tested it I put a voltmeter across the charge circuit.At cruising revs, it puts out about 14.5V, so that's ok.At peak revs it's whacking out 19V - not so good, but the motor's never run at this speed.
pup2,
Dec 22, 3:28am
Cheers, new about the sulfahation, never realised a reg would sim a de sulfation mode the same as a charger. De sulfation on 12v, would that be getting close to 16v. Have heard of people giving the battery a tickle up on 24v charger to bring the life back to the battery due to sulfation
pup2,
Dec 22, 3:31am
Calicum requires min 14.2 to charge. I wouldn't use a sealed battery on a solar panel. They can use water, so it pays to keep an eye on the levels and top up as required
mechnificent,
Dec 22, 3:34am
My solar regulator goes to 14.8 for an hour if the batteries have been below 11.9, or, once a month. After the hour, it regulates at 14.5 tapering down to 13.6.
solarboy,
Dec 22, 4:17am
A 12 volt solar panel will read 19 volts plus on open circuit too - ie not connected to a battery like i presume your outboard charging circuit was when you read it.Once either is connected to the battery the voltage will drop back to 12 to 14V or so depending on the state of charge of the battery.
mm12345,
Dec 22, 4:40am
Yes - the 19v was without any load.People do have issues with boats using charge circuits from outboards.VHF's don't like the voltage, current draw is low on receive, so they tend to blow if a battery terminal comes loose but the switchboard is still connected to the charge circuit.It pays to be careful how the battery is connected up.
the-lada-dude,
Dec 22, 1:19pm
is it sulfation that eventually causes a battery to fail overtime or or PbO2 falling off the plates !
intrade,
Jul 2, 9:19pm
on the battery it will say what currant it runs at like above calcium need higher current to charge to full. set it acording to this not if it seald or not. Ps there is better regulators out now that charge from solar more efficiant however like all things not cheap and made in germany not china.
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