Help! Electrical problem!

[Valkyrie]

Hi Brats,

Valkyrie has developed and electrical problem: the house battery won't keep a charge and the battery (an AGM Bluetop) has been tested as okay. There must be a short or drain somewhere.

Initially, when Marcia and I left for a day of fishing on Lake Erie, the low battery warning device on the GPS went off and the voltmeter showed 5 volts (!) for the house battery. The Honda didn't seem to help any.

I took it to a Honda dealer/marina down the harbor and a week later they told me that it had a dead battery! That's why I took it in. They took out the house battery, charged it and put it back in. The charge didn't hold for four days and was down to 11.5 volts.

Oh yeah, prior to taking it to the Honda dealer, Marcia noticed a clicking sound form the lazerette and she noted that the clicking increased with higher rpm's. I heard it, too, when I wentback into the cockpit when Marcia ran the boat.

Here's another strange part. Since the battery was charged and we picked up the boat, the clicking has gone away, but still no charge.

Note: when we leave the boat at our dock, all switches are off except the bilge pump, which is left on Auto.

I have a guy coming to look into it in a few days, but thought I would throw it out here first. Any ideas?

Question: I have a BEP VSR switch. Does it normally click softly for about 10 seconds on start-up? I think that it is determining the charge state of the Start battery before switching over to the house battery. I never really had reason to open the lazerette on starting before this. Am I interpreting this correctly?

Thanks in advance for the help.

Nick
"Valkyrie"

[Not For Hire]

Hi Nick,

The sound you hear is so called "chattering" It is caused by the VSR switch cycling rapidly back and forth between open and closed. It does this when the 2nd or house battery is very depleted. So what happens is the charge battery reaches 13. 7 volts after you start up, the vsr closes to start charging the house battery but since the house battery is so low in charge the the voltage immediately drops and the vsr opens again breaking the connection to the house battery. Since the start battery is actually fully charged the vsr detects good voltage again and recloses. It can do this several times per second. It is not abnormal for this to happen for a few seconds at startup. This is also why BEP cautions not to have too big a house battery for the system.

If you hear the chatter and you raise engine rpms to fast idle the chatter should go away as the output from the engine should be enough to keep the charge up on the start battery even with the vsr open. (This works better with Yami and Suzukis with their larger alternators but the Honda 90 will work fine also, it works better than the cautious BEP tables below).

Now this does not answer the ? about where your juice is going.

So some ?s

Is the start battery holding a good charge?

If so then,

Are you sure the house battery is draining when you are away from the boat or is it only when you are using the boat?

If it is the former then you have to track down the drain. If the latter then when you go on a cruise the house is not being charged at all? If this seems to be the case start with two charged batteries and bypass the vsr switch. Let the batteries run in parallel by closing the combine switch (sometimes called emergency start switch or whatever). At the end of your cruise if both batteries are fully charged then the problem may be in a faulty vsr switch since the system is actually keeping up with your usage.

On your boat the big juice eaters are windlass, radar, wallace at startup. Your alternator should keep everything charged unless you are using the windlass a lot.

Regards, Mark

Some stuff from the BEP website.

How it works:

The first priority of any charging system is always to ensure that the engine starting battery is charged and ready to go. It therefore follows that the VSR's first job is ensure that the engine battery is recharged and once again "ready for action". The VSR does this by staying open when the engine is first started and remaining open until the engine battery's charging voltage has reached 13.7 volts.

Once this voltage has been reached, the relay closes, allowing both batteries to be charged together.

When the engine is switched off and the voltage drops below 12.7 the relay automatically reopens, separating the two batteries and ensuring the engine battery is safely isolated in a fully charged state.

Another advantage of BEP's VSR is that the house battery is completely isolated from the engine battery during the voltage-hungry starting procedure. This means that, as long as all electronics are powered by the house battery (as they almost certainly will be), they will not be subject to damaging voltage spikes during start up.

Ensuring correct sizing:

The charging system must be correctly sized to the batteries (see figure 1).

If the charging system is too small for the batteries the VSR system will not work properly. Instead, once the starting battery has reached the right voltage and the house battery is connected, the system's voltage will "cave down" below 12.7 volts and the relay will automatically disconnect. The voltage then rises, the relay re-engages; then the voltage drops, the relay disengages and a buzzer-like sound will be heard as the relay quickly switches in and out.



Dimensions: (L X W X D) 69mm x 69mm x 50mm

Part No:
710-100A: For use on 12 volt charging systems up to 100A/12V.
710-100A-DS: 100A/12V Dual sensing systems (special order).
710-100A-24V: For use on 24 volt charging systems up to 100A/24V.



Figure 1
Alternator verses Battery Capacity:Alternator size Second Battery Size
10 amp 60 amp hours GRP 22
16 amp 85 amp hours GRP 24
25 - 35 amp 85 - 100 amp hours GRP 27
50 - 60 amp 100 - 130 amp hours GRP 31
80 - 90 amp 130 - 220 amp hours GRP 80

Standard 100Amp VSR's have single sensing setup.
Dual sensing units are available upon request (710-100A-DS).
This can be used where a battery charger or second charging source is used into the house battery

Common example:

On a Yamaha 115hp outboard with a 16 amp charging output the house battery should not be larger than 65 amp/hr.

Installation:

Connect the VSR to the back of the battery isolating switches, ensuring that the battery cable is correctly sized. This will ensure good current flow to the battery, reducing the likelihood of voltage drop to the VSR

The LED on the front of the VSR should be visible, as this will instantly show when it is in operation.

Note:

When using a VSR in conjunction with a high performance voltage regulator (eg Next Step regulator) the regulator sense wire must go to the same point as the sense for the VSR ie the start battery.

Frequently asked questions:

Question: To which side of the battery switch should the VSR be wired?

Answer: It is very important to following the wiring installation diagram as this shows which connection should be on which side of the master switch.

If the VSR is incorrectly wired into the circuit, it could continue to provide power a system that appears to be isolated (eg: even though the house master switch is turned off, the house system is still able to draw power through the incorrectly wired VSR. (see figure 2)

Question: How do I ensure that the correct size of battery is matched to my VSR?

Answer: Check battery sizing chart.

Question: Why does my VSR "chatter"?

Answer: Because the charging system is too small for the batteries and this is not allowing the VSR to work properly. Instead, once the starting battery has reached the right voltage and the house battery is connected, the system's voltage is "caving down" below 12.7 volts and the relay is automatically disconnecting. The voltage then rises, the relay re-engages; then the voltage drops, the relay disengages and the "chattering" sound is heard as the relay quickly switches in and out.

[drjohn71a]

Mark, could you be a little more specific? JJ John

[Valkyrie]

Hi Mark,

Thanks for the info! It is steering me toward the solution, I hope.

The start battery is always at full charge and the drain occurs when we are away from the boat. In use, the house battery seems to be topped off and all was well, until recently.

When cruising or fishing, we run the VHF, radar and GPS. I always start the engine when I start the Wallas and the same is true for the windlass, especially since we have 150 of chain, and THAT is going to change for next season.

I guess there must be a drain somewhere in the boat and I hope that the local electrical guru will find that this week. Interesting thing, when I talked to him today and I mentioned that we had a C-Dory at Bass Haven, he replied, "Oh, I know that boat!" There are over 500 slips at our marina.

Mark, will you please email the picture of me holding that King that you posted in my thread on our fishing trip? Thanks, and I'll send you a few, as well.

I'll let all know about how this little snafu works out.

Best regards,

Nick
"Valkyrie"

[Sea Wolf]

Ask, and you shall receive.

[MOOSE]

[thataway]

Great post by Mark. In the tool box you should have a hand held digital volt meter (a good one will cost less than the tech's time) You need to start looking at how much discharge there is via the amp setting (most good meters will have a separate fused circuit (second place the lead is put into) for up to 10 amps. I suspect that the drain is less than 10 amps.
Put the meter, set on amps, between the + post of the house battery and the cable going to the distribution pannel. There may be one or two other cables off the Positive terminal of the battery. The bilge pump may be there, and in some C Dories the Wallas stove comes off directly.

One of the most common causes of the "leak" is corrosion in a wire, especially in a bilge pump circuit--often the float switch. You can systematically go thru the circuits finding out where the "leak" is. The C Dory is a relitatively simple boat, but often folks have added wires thru the years and it becomes a bit more of a "Rats nest" of wires. While you are going thru it is a good time to make lables for all of the wires. Put them around the wire at the appliance and at the back of the distribution pannel.

Good luck finding what is draining the battery. Even AGM's can be damaged by very deep discharge. So there is a possiblity that your battery has shortened its life. We always have a spare small garden tractor battery on a single engine boat, which can give a surprising amount of power if you loose the main battery for some reason.

[Valkyrie]

Problem solved!

The bilge pump at the transom was toast. In fact, the very top of the Rule 1100 was actually convex, sort of bubbled out, from heat and the impeller (right term?) wouldn't even turn.

I replaced it and all is fine.

Thanks for all of the advice!

Best regards,

Nick
"Valkyrie"

[Almas Only]

Nick:

I understand you're having some ongoing electrical issues, and to the extent they are attributable to charging, I have a suggestion which might help out.

IMHO, most installations on C-Dory boats powered by Honda 90's which use any form of automatic battery selection switche for charging are connected backward. By that I mean, they give first priority to the starting battery, and second, to the house. I know this will provoke all kinds of comments about how the first priority is to have a well charged starting battery, and that isn't in dispute. That's why all direct connections, such as the wallas, and automatic bilge, should be made to the battery designated for house use.

However, if you were to start the day with both batteries at full charge, supply all needs while underway from the alternator, and not provide any charge to either battery, which one would be the most depleted the next morning? Chances are, it would be the house, because starting the motor puts a high, but relatively brief, amp load on the battery. House loads, although lower, are of a much greater duration. You can do the math for any application, but I'd be willing to bet that the house battery is the one supplying the most amp-hours.

So, if you've drawn the house down, and the starting battery is at or near full charge, why not charge the house battery first? So long as you monitor and record your voltages with some regularity (if neither battery is too depleted, you can do that on the gps, without having to mess with a separate meter at the batteries), the alternator will first supply current to the ongoing loads, and the "primary", now house, battery first, and once the house is topped off, kick in the "secondary", now starter, and supply current to all three uses.

This will avoid having the starter fully charged, and the automatic switching unit going into a funk over the fact that the secondary battery is so discharged. If it's the "primary" that's discharged, the automatic switching gear simply sits on the side line, while the alternator brings that battery up to charge. There's nothing for it to go into a funk over. Only then, after the primary is charged, does the switching take place, and then, it's switching in a relatively well charged starting battery as the secondary.

Thoughs?

david

[Valkyrie]

Answered via PM.

See detailed response below.

Nick

[flapbreaker]

Alma,

I agree with your assessment. I constantly struggle to keep the house battery charged on a long day of fishing. Then when I start up the main the VSR switch goes crazy until the house battery get's a better charge. Can't think of a good reason not to reverse the switch but maybe someone else can?

[mikeporterinmd]

On a Honda, there is no easy way to split the alternator output from
the starting power, so basically, I can't wire the Blue Sea ACR (which
I think is similar) except to give the starting bank priority.

I guess I could get to the regulator output and run a wire out of the
engine...

Mike

[oldgrowth]

I will have to watch this thread also. I have thought of reversing mine also, but have just turned my battery switch to both until the house battery gets a little charge then switch it off.
_________
Dave

[Valkyrie]

Hi Brats,

Good advice from all, but first, a word of explanation: Alma's Only went back and looked at my old post due to a PM between us. That is why this came back up again.

The info from Not for Hire and Thataway were spot on. I did find a bad bilge pump, an unfused one at that, which was installed when the boat was rigged before we took possession. That was two problems ago. In an earleir post I mentioned that the problem was solved, but it wasn't.

Subsequently, it was found that more than the Wallas and bilge pumps were wired hot, and NOT only to the house battery, thus a constant drain on both batteries. This was found by the local electrical guru, at our expense.

This has been a four or five layered continuing problem, depending on how you count. Peel one layer of the onion and there's another.

Thanks for all of your help and advice. You are what makes this site so great.

Nick
"Valkyrie"

[Almas Only]

Mike:

There are two posts on the ACR. In a "standard" setup, your starting battery is connected to the primary post, and your house, to the secondary. If you reverse the two connections between the batteries and the ACR, then the house will be the primary, and charge first, and when it's charged, the secondary starting battery will be given charge. You don't have to split the output from the alternator. Other than what's consumed by uses such as motor's electrical system, radar, radio, etc., all output from the alternator goes to the primary battery until it is charged, at which point, the ACR brings the secondary on line, along with the primary, so that the seconary begins to receive charge. The only question is whether you charge the house or starting battery first, and that's determined by the posts on the ACR to which they're attached. The ACR can't tell the difference between the house and starting batteries. It gives priority to whatever happens to be attached to the priority post.

david