Are My Batteries Toast?

[Pitchondesign]

The 20 hour test is clearly better and more accurate no argument. It is however far less practical. So, what I'm left with is, doing nothing and hope for the best, rely on the onboard monitors, or use one of the newer testers. I'm a cruiser, not a professional battery engineer. What I care about is a working reliable battery bank. I'm OK with not knowing the precise battery capacity. What I need to know is how my batteries have aged and will they make it through the season.

[Paul L]

Originally Posted by Bleemus

....

In summary your Magnetronic is just guessing at SOC during the charging cycle just like the SG but the SG is more accurate. MaineSail was skeptical that this could be possible but his testing proved otherwise. Thats good enough for me.

You have this backward. The amp-hours battery monitor, Magnetronic, is as accurate during charging as it is during discharging. The SmartGauge is the one 'guessing' during charging.

[john61ct]

All AH counting monitors are just guessing SoC all the time.

So yes just as (in)accurate in all situations.

While charging, the source controller is (should be) measuring its current input to the bank, and only ending Absorb when amps drop down to 3A, or 5A, whatever.

This is as accurate an indicator of 100% full as anything can be.

[StuM]

Originally Posted by Kenomac

Which is better for my batteries? One 1.5 hour generator charge in the morning then solar once every two days.

Or one 0.5-0.75 hour generator charge daily then solar.

Daily, that will keep your minimum and average SOC higher.

[a64pilot]

I would not run anything for only a half hour if I could help it, if I crank a Diesel I want it to run an hour min, under load, that way it gets fully warmed up and the oil gets hot enough to cook off moisture. Your not saving anything really with a short run, so if your going to run it daily, run it an hour or more.

[mitiempo]

Originally Posted by Pitchondesign

The 20 hour test is clearly better and more accurate no argument. It is however far less practical. So, what I'm left with is, doing nothing and hope for the best, rely on the onboard monitors, or use one of the newer testers. I'm a cruiser, not a professional battery engineer. What I care about is a working reliable battery bank. I'm OK with not knowing the precise battery capacity. What I need to know is how my batteries have aged and will they make it through the season.

I doubt you will get very good accuracy with a $55 tester as far as capacity is concerned. Even expensive testers are not that accurate.

Are Battery Impedance Testers Worth It? Photo Gallery by Compass Marine How To at pbase.com

[poiu]

Originally Posted by Kenomac

At this point, do I need to go up the mast before I try to unfurl the sail to take it down? Is there something I can accomplish by doing this to minimize the damage? The company that makes the swivel is currently shut down for while.

I don't think you need to go up now. If you can furl it easily now and without clicks and bangs and jams then there probably is not much or hopefully no damage at all. The damaged area will be under the swivel if there is any damage and you will really need to drop the swivel to see it properly. That means dropping the sail ideally. You've probably got the odd still half day or more with August weather, so it shouldn't be too hard to check out.

To minimise damage you can reduce the halyard tension prior to any operation of the furler in or out. As you have no balls in the swivel, that really is a essential measure right now. The damage is caused because the swivel is twisted out of parallel by the pull of the halyard. The more the halyard pulls, the more the damage the swivel does to the foil. Damage is now much worse because with the balls missing the swivel is even more out of parallel with the foil.

If you can get hold of some balls you can reassemble it. You may be lucky that the swivel is undamaged and you can do this, but I doubt it. If you kept a ball or can find one in the swivel, when you drop the sail the you can measure it to source new ones. They will probably be torlon plastic.

Getting the swivel off is a palaver. If it comes to it, ask Formula Spars for help as your equipment will be slightly different from mine or if they are not available then I can try to give you instructions.

[Kenomac]

Two trips up the mast to gently lower the sail, the swivel was repaired using new bearings and greased within two hours. Now it's as good as new for under $75.

[Kenomac]

The Smartgauge has taken about a month to "smarten up," and now seems to be working well.

With the deep freezer shut down because we haven't yet caught a tuna this season, the house bank drops to 84-86% overnight, then rises to 98-100% with only 450w of Solbian solar during the day. No generator needed unless I require some hot water which then necessitates a 45 minute run to heat 14 gallons at anchor. Since we cook using 100% electric, we sometimes run the generator if cooking time lasts for more than 1/2 hour.

Note: We keep the boom pushed off to starboard in order to prevent shading and we use five individual controllers to get the most out of our solar. People ask me all the time why the boom is moved out, after I tell them why.... I then see their boom pushed out the next day if they have solar.

[john61ct]

Excellent progress.

Do you think your Magnetronic is back to working properly?

Your "when to stop the genset" should really be based on current dropping, do that in the morning so your solar can finish the long tail, ideally amps flow drops to 2A before the panels stop producing in the afternoon.

Keep a log of that number, until your instinct can take over, runtime will vary with morning SoC and weather conditions.

Have you decided to start equalizing yet?

[Kenomac]

I won't be able to equalize until early October when I plug into shore power for the first time in five months.