Sully's battery problem

[ssullivan]

Wheels, the Link 10 is not a charge controller. It's the battery monitor Rick (from WA) had a hand in creating. It is blown out and blew out before I got the boat.

The shunt is the Link 10's shunt that ships with it from the factory. I know since I have the same setup in my land boat.

Damn... these electrical problems stink.

So do I tie the two different negatives (grounds) together and say "to hell with the huge current between them?" I'm a little scared to do it, thinking I might blow something out.

[slomotion]

Not gonna touch the electrical issue (especially if the AWG 1/0 cable is vibrating). But, if Alan is right about the paint on the props, make sure this same paint has not been used on the sail drive cases. If it has, get it off fast. Copper based paint on aluminum sail drives can sink your boat.

It may be some comfort to know that about 800,000 Florida Power and Light customers lost power today.

[ssullivan]

The Xantrex Inverter/Charger is satisfied that the batteries are at full capacity right now. It has gone to float charge at approx 13VDC. I can confirm that the house batteries are 13VDC, terminal to terminal.

Now, when I check against my engine block ground, I am seeing only a .3V difference between that ground and my floating ground. It was 1.4V early today, later today I mentioned it was about 1V, and now... it's .3V, at fully charged battery.

I'm lost here. The more I charge up the batteries, the closer my two "grounds" come to being the same potential. What could possibly cause something like this?

PS: The Xantrex charge controller (for the solar and wind) is blinking a single green flash now that the batteries are up at float via the Xantrex inverter/charger. According to the manual, this means the batteries are "seriously below" bulk voltage. Not adding up at all. Time to rip out the charge controller, as Rick M had suggested earlier today, I guess.

Gotta stay inside though... bugs are getting ready to pounce!

[ssullivan]

Originally Posted by slomotion

Not gonna touch the electrical issue (especially if the AWG 1/0 cable is vibrating). But, if Alan is right about the paint on the props, make sure this same paint has not been used on the sail drive cases. If it has, get it off fast. Copper based paint on aluminum sail drives can sink your boat.

Uh oh... I don't recall if they were painted or not...

Anybody know any good places to beach a cat in Key Largo, on the ICW side?

BTW: Now that the house bank is charged up, the 1/0 cable doesn't vibrate so much when quickly jumpered. This is getting a bit crazy.

[slomotion]

I have no experience with saildrives and probably you wouldn't sink, but from the logs of Ocelot:

"We made a mistake the last time we hauled by painting the bottom of the dinghy, outboard, and our saildrives with a copper-based antifouling paint - and all of those surfaces are aluminum. This may be why the paint has been peeling off the dinghy. More importantly, we saw the catamaran "Hibiscus" in Panama (we'd actually sailed on her in Florida when we were looking at boats) that had both of their saildrives rot-out on them from copper paint reacting with the aluminum - they had to throw them away!"

On The Hard

[Tropic Cat]

Originally Posted by ssullivan

The Xantrex charge controller (for the solar and wind) is blinking a single green flash now that the batteries are up at float via the Xantrex inverter/charger. According to the manual, this means the batteries are "seriously below" bulk voltage. Not adding up at all. Time to rip out the charge controller, as Rick M had suggested earlier today, I guess.

Bugs? What bugs? Sean the only bugs we have this time of the year are all running around in your boat wiring .

Jumpering out the controller was always my plan 'B'. If you have a 1 volt differential when measuring battery bank voltage against ground in two different parts of the boat .....to me, running that down is plan A. If you're measuring 13.6 volts at an engine block ground and 1 volt less at the output of the charge controller, I would pull the output wiring to the batteries off that controller and clean up both ends of these wires. Put them back and see where you are.

I would not attempt to tie the grounds together . However you look at it, between these two grounding points there is at least 1 volt of electricity and therefor there will be current flow. The object is to run down the reason this is happening.

[senormechanico]

"I'm lost here. The more I charge up the batteries, the closer my two "grounds" come to being the same potential. What could possibly cause something like this?"

You must have a high resistance in that negative leg. When the batteries were down,(the 1.4v drop) they were asking for more charging current than when they finally charged up (the 0.3v drop). The same resistance will drop less voltage when there's less current going through it.

Find that bad connection causing the resistance. It's probably either a corroded or loose connection, or a corroded wire, but it's obvious to me that it's between those two points you measured the voltage drop.

The reason the wire was vibrating in your hand when you jumped the two ends of your 1.4 volt drop is because the dead batteries were asking for the full output of your charger and they were getting it! That's NOT to say that your batteries are in perfect condition, but one can hope.

Steve B.

[Alan Wheeler]

OK Sully, here is a link to a circuit layout. http://www.xantrex.com/web/id/1224/docserve.asp
This may help you make sense of how it all works.

Here is an important point to always remember. You must never jumper one battery system Neg. across to another system Neg. if the Negs. are connected elsewhere. If you draw that out on paper, you will see you simply have a circle or loop. And a voltage can the flow across that cable. So you should have one and only one common point on your engine that the Neg. of the battery is connected to. You could have several other cables also connected to that one point. One of these should be an Earth cable that runs to the Freedom chg/invt Chassis. That one ties your AC earth to the Boat Neg.

Umm it could be a good point to ask at this time, which model Freedom do you have. The old black box, the newer white box or new "spaceagy" looking aluminium extrusion box??
I have the black box Freedom 25 and the Link 2000 controller.

OK, back to the wiring...the negs. should all tie back to that one common point. The other engine can be linked across to the engine being used as the common bond point. But that other engine should not also be tied back to the battery Neg in any way. This same wirign scheme could be seen in two ways. A Neg. running to each engine, or to one engine and then across to the other and terminating there. But no cable should compleate a circle back to the battery. Gee I hope that all made sense.

[ssullivan]

Will try out all input to this problem in the AM. Right now, it's midnight. I went to bed at 9PM with a full battery bank via the Freedom shore power charger (space age).

I left the 10A refer running for the night to test the 540AH house bank and see if it was in good shape or not.

As of this midnight (only 3 hrs later), I'm back down to 11.5VDC. The batter bank is definitely bad.

SO... I'll replace the bank tomorrow AM and then continue down the path of checking connections and stuff.

Thanks for the input so far. I will verify the engine grounds (from the freedom) in the AM as well. That's very important, as are clean terminals. Since I'm putting new batts in, it should be a good opportunity to shine them all up!

Thanks!

[Alan Wheeler]

Don't go buying new Batteries just yet, till you can confirm your batteries are the fault. First thing you need to do is work out if the banks are actually getting charged. Voltage readings won't tell you that. The best money you could spend would first be a new Link monitor or work out what actually is wrong with the one you have.
540Ahrs is a lot. That is one heck of a lot of charge time. If you have the panels in full sun, they could be providing 25Amps. If you have had a good breeze of over 10knts all day, you may have another 20A provided there. So you will need 12hrs of both that just to get the bank to 80%.
On the other hand, don't go by your voltage reading when the inverter is running. The reading will ALWAYS be lower than the battery at rest voltage. If when you reading was 11.5V and you disconnected the inverter, you would see the voltage rise again. It is that voltage that is the telltale reading you need. So once again, you really need that link10 to give you the Ahr reading to be really accurate.

To make your system easier to understand, I would be looking at combining the two house banks to one bank if that is at all possible. If the two banks are in seperate hulls, that is going to be a problem and you will have to keep the two seperate. Together means you can get rid of complexities and be able to monitor one system. The issue you have is that you have a one system charger/monitor with two banks.

In regards to the props, don't fret. You don't have to go rushing up on to a beach anywhere in the next few hrs. The copper is not good on the legs, but at the same time, it does take awhile for the damage to occur. I suspect that it will have already if the anodes were gone. The copper may also be gone as well now.

[Alan Wheeler]

Sorry to keep giving you more to read mate. Just to put you at rest on a couple of points. You can not overload the charger. It is protected from over load and over heat. It also has a low voltage cutout on it, so if the battery drops below a certain point (10.5V I think) it will automaticly shut down. The house bank can actually drop to 10.5V while the inverter is powering say the fridge. The 10.5V is the load voltage across the battery, not the rest voltage. Don't think the two are the same, they are not.

[ssullivan]

Thanks, Wheels. Good, sane ideas on a less than sane week.

Now, I did test out the battery bank last night. I may have not been clear since it was after midnight when I updated.

I used the Freedom *shore power* battery charger from close to noon yesterday, until 9PM at night. My goal was to charge at least 80% or so. This is a 70 amp charger that showed me that the batteries were fully charged and in float before I went to bed and turned it off. They were in float for hours (maybe from 6PM on?)

I disconnected the *shore power* charger at 9PM, went to bed and left the refrigerator on full blast (a 10A load at max). The upside?? Nice, cold milk for my cereal this AM!

The downside? The bank was reading in the mid to low 11.5VDC range or so at midnight last night. The shore power charger (even though it was off, it still reads the batteries and reports status), was reading that the batteries were in a low state, well below the normal range of operation.

If a 560AH battery bank that was in float stage is reading 11.5VDC under a 10A load only 3 hours in, it's a bad bank, agreed?

I will get new batts this AM and then go through all the connections as I install the batteries, including making sure everything is sharing a common ground one way or another.

WHEW! Big relief about the sail drives. I couldn't afford to buy new ones until I get the boat up North and working. That sure was a scary one!

Thanks for the help so far. I'm trying everything mentioned, plus getting new batteries. Does it help to say the bank is bad if the owner was there pouring distilled water in the night before my first view of the boat??

[Morgan Paul]

Does it help to say the bank is bad if the owner was there pouring distilled water in the night before my first view of the boat??

At least he didn't pee in them . Can't offer any other advice. But good luck.

[ssullivan]

And the mystery continues!

Terminal to terminal multimater voltage on house bank: 13V

Voltage as read by the Freedom shore power charger: 12.5V

Hygrometer reading: 1.99 (dead)

Charge controller for solar: one blink, indicating battery well below bulk charge.

#@()*$ #@) &%*@# (tha't me swearing up a storm)

[ssullivan]

Bassed on all of this data disagreeing and the fact that the 560AH bank went from full charge to 11.5VDC in under 3 hrs last night, I guess it's time for new batteries and then to test things out some more. I think the hygrometer is the most accurate, right?