shore power/batteries

[harleydude777]

Hi all, O.K. so attached is a pic of (part of) the breaker panel on my 1988 IG36 and my question is, if i want to charge all the batteries while plugged into shore power (currently in heated storage) do i put the top switch on "ALL" and of course the bottom one on "shore"? Not sure what 1 & 2 are as far as which one is the starting batt's bank and which one is the "house" bank, so figured "ALL" would cover both? are all IG's pretty much the same as far as the 1 & 2 hookup? thanks in advance.

 

[tiltrider1]

From just looking at the picture it looks like All would charge all your battery banks. This however is a dangerous assumption as I have no idea what your battery charger is connected to and what is connected to the switch in the picture.

Also, I don't know what type of charger you have and can't be sure that you won't just cook your batteries over the winter. Would recommend that you check battery fluid level and make sure its topped off.

Just a note. The bottom switch is connected neither to shore nor the Generator. This means nothing will get charged.

 

[Comodave]

The battery switch is likely to select which batteries you want to draw power from. The battery charger usually is connected to all battery banks and will charge them regardless of the battery switch position. You could have the battery switch in off and they should get charged. At least that is how all of my boats have been. The battery charger runs off 120 volts so if it is turned on the batteries should charge.

 

[DeanOz]

On my IG 32, when my selector is on "shore power", the power goes through to my battery charger unit, which then charges all batteries connected to it. My understanding of the selector switch is just as Comodave says. My "start" battery is #2 and when I'm on a trip and get to my destination, I shut the engine off and switch over to the "house bank" on #1. That way I have enough juice to start the next day.

 

[BruceK]

I own an Integrity 386, derived from the IG 36. Same builder, Jiang Hua.
As Dave says, the switch determines which battery you draw from. But running engines, it determines charging. The "Manual" for my boat says to switch to one of the positions, I think it`s 2(I need to check for certainty), unless charging both batts from one alternator.
The guy who delivered my boat 600NM from Melbourne to Sydney is a marine electrician, on route he texted me a diagram I don`t fully understand,saying "This is why don`t select "All".
I`ll visit the marina soon, now I`m Covid negative, and check and advise.
EDIT:Just saw Dean`s post, I think we`re on the same page. One thing though, I used to preserve one batt as start, using the other as house when anchored, but reasoned I was running the house designated one down a long way, it was better to use both to more moderate levels of drain with the genset as back up to revive them if the worst happened, which never has.

 

[DeanOz]

I`ll visit the marina soon, now I`m Covid negative, and check and advise.

I hope you didn't get too ill with C19 Bruce.?️

 

[BruceK]

I hope you didn't get too ill with C19 Bruce.?️

Thanks Dean, I think largely due to a very recent booster I avoided the nastier symptoms. My younger partner, last booster in April, had 2 nasty chill/fever/SOB nights onboard. We and 800 others(excl crew) got it on the Majestic Covid Princess, which after unloading 800 in Sydney unloaded another 200 +ve pax in Melbourne. Definitely best avoided.

 

[Bacchus]

I agree with Dave that sw likely only determines draw from batty... if single could also determine alt charging when running.
How shore charging is connected can vary and best / only way to know for sure (and avoid possibly destroying a batty) would be to do some tracing at least of shore charger connections.
It's a bit of a chore but you will likely learn a lot about your elec system...
Our remote comments can only be speculation and I would not consider them as fact... only something to be confirmed with inspection, multi meter.
A clamp on DC ammeter can make confirmation of charging fairly easy.

 

[harleydude777]

thanks guy's.....so if i left the top switch to "off" and the bottom to "shore" and then turned on the "charger" breaker switch ,the panel would be drawing directly from shore power and NO BATTS, but at the same time charging both Batt Banks? is that my understanding? and BruceK, if you can find out why your guy said (The guy who delivered my boat 600NM from Melbourne to Sydney is a marine electrician, on route he texted me a diagram I don`t fully understand,saying "This is why don`t select "All".) that would be greatly appreciated. there is a reason he made that very clear to you.....thanks again for all the info everyone......it is a BIG help.

 

[Comodave]

No, most likely is that you need to have either 1 or 2 or both battery banks selected to power the 12 volt side of the panel. With the shore selected and the battery charger breaker (120 volts) on then the batteries will be supplying power to the 12 volt panel and will be charging off the battery charger. As to how the engine alternators charging the batteries you would have to follow the wiring and see how it is connected. The alternators may be wired so they charge through the battery switch or they may be directly wired to the batteries.

 

[Bacchus]

thanks guy's.....so if i left the top switch to "off" and the bottom to "shore" and then turned on the "charger" breaker switch ,the panel would be drawing directly from shore power and NO BATTS, but at the same time charging both Batt Banks? is that my understanding? and BruceK, if you can find out why your guy said (The guy who delivered my boat 600NM from Melbourne to Sydney is a marine electrician, on route he texted me a diagram I don`t fully understand,saying "This is why don`t select "All".) that would be greatly appreciated. there is a reason he made that very clear to you.....thanks again for all the info everyone......it is a BIG help.

If you want to know for sure - do as you say and put a meter on the battys to see if they are getting charged. Otherwise everyone is guessing and you may end up ruining a set of battys.

 

[tpbrady]

Perhaps the best way to see what is connected to what without following cables in bundles is a voltmeter, a piece of paper, and a label maker. With a charging source on, you should read 13.4-14.4V at the battery switch with the switch in the all/both position. You should also see the same voltage on each battery/battery bank. When you switch to the "1" position, you should see 13.4-14.4v on one of the batteries either start or house. This also would indicate that the charger is connected to the load/panel side of the battery switch. In the "2" position you should see 13.4-14.4v on the other battery. The battery isolated from the charger should show less voltage that declines over time to 12.6v or so. If the charger is on the battery side of the switch, it is probably connected to only one battery/bank and turning the switch to any position wouldn't change the voltage from 13.4-14.4v. Charging current would only get to the other battery when the switch was in the all position. The alternator would more than likely be connected to directly to one battery with no switch, otherwise you risk frying the diodes in alternator by not presenting it with a load.

There are several other ways to set this up, but a volt meter is the best tool for sleuthing things out. Personally I like a ACR (automatic charging relay) or an Echo Charger for the start bank, making the battery switch the device that shuts all DC off to the boat or in the event the ACR or Echo Charger fails, you go back to the manual switch to control charging.

Just be sure to write things down as you discover them and put a label on it when you are done. I'm 9 years in on our boat and still finding things out and making labels.

Tom

 

[catalinajack]

No, most likely is that you need to have either 1 or 2 or both battery banks selected to power the 12 volt side of the panel. With the shore selected and the battery charger breaker (120 volts) on then the batteries will be supplying power to the 12 volt panel and will be charging off the battery charger. As to how the engine alternators charging the batteries you would have to follow the wiring and see how it is connected. The alternators may be wired so they charge through the battery switch or they may be directly wired to the batteries.

Rod Collins (marinehowto.com) recommends that alternators be wired directly to the batteries.

 

[SteveK]

Rod Collins (marinehowto.com) recommends that alternators be wired directly to the batteries.

looked in marine how to and could not find, so.
As opposed to where? Can you give specifics or the reason.

 

[Comodave]

Rod Collins (marinehowto.com) recommends that alternators be wired directly to the batteries.

Yes, but that may not be how his is connected. He will have to trace out the cables to see. Then make any changes he wants to.

 

[Iggy]

If it was my boat. I would trace all the wiring out as to the battery switch and charging. We don't know if anything was added or changed after the boat was made.

Yes you could take voltage reading, but there could be VSR or isolators added.

 

[Bacchus]

Rod Collins (marinehowto.com) recommends that alternators be wired directly to the batteries.

That doesn't mean boat mfg read or follow RCs recommendations.
Mainship did not.
In fact it is not unusual for mfg to use the starter feed for charging. So if that is switched,mwhich it frequently is, then the alt charging is also dependant on switch position. That's one of the main reasons they make / sell switches with the field make before break feature to avoid frying alts when switching.

 

[sunchaser]

Rod Collins (marinehowto.com) recommends that alternators be wired directly to the batteries.

Sure if you've only got one engine and one battery. My genset is set up this way. But then, look up how Rod recommends including an ACR in the circuits when one has twin engines, separate start bank and a house bank. Then toss in a thruster and or windlass bank.

 

[Iggy]

Sure if you've only got one engine and one battery. My genset is set up this way. But then, look up how Rod recommends including an ACR in the circuits when one has twin engines, separate start bank and a house bank. Then toss in a thruster and or windlass bank.

Thats why I suggest to trace the wires. Write down in a drawing of how the charging circuit is wired.

 

[tiltrider1]

Thats why I suggest to trace the wires. Write down in a drawing of how the charging circuit is wired.

This is what I was eluding to in post #2.

 

[bill.kimbell]

Hire an electrician

My suggestion - if you do not understand your electrical system, hire a certified marine electrician for as many hours as needed to learn what you have, what you should have, make the changes necessary. As soon as you go beyond a simple 12v boat, the complexity rises dramatically - as well as the dangers of making mistakes.

Suggested with the best of intent, no judgement implied.

 

[MVDarlin]

Battery charger will run on shore power or gen set.. It should have separate circuits running to charge both the house and the start bank, regardless of what setting the "Perko" switch is at.

 

[Flatswing]

As others have noted, the Perko switch in the original configuration would select which battery you are drawing from independent if the shore powered battery charger. Many people when anchored overnight would set the switch to position 1 or 2 leaving the other battery untapped for morning starting. Typically but worth confirming, this is a “make then break” switch that allows you to switch from 1to 2 to all (but not off) while the engine is running without frying your alternator diodes.
But that was in 1988. Lots have changed on your boat since then. Almost certainly, your shore powered battery charger has been replaced, possibly rewired, so time to grab a flashlight, knee pads, a DVM and a pen & paper and start following wires. Absolutely worth your time.

Many GB36 also have 2 silver on/off battery disconnect switches under the steps to the forward cabin if it is a classic 36. These are safety switches that disconnect the starter and alternator from its respective battery, for working on those parts safely.

But you are in inside heated storage so, assuming you have AGM batteries, you don’t need to leave power on for bilge pump or to charge the batteries. In VT, (inside unheated storage) My yard routinely charged the batteries, then disconnected all positive cables from both batteries. Come Spring, charge, load test and off you go.
If you need 12v lights to check on the boat occasionally, the battery charger should provide enough amps without the batteries in the circuit. But best to leave off when you are away from the boat.

 

[BruceK]

thanks guy's.....so if i left the top switch to "off" and the bottom to "shore" and then turned on the "charger" breaker switch ,the panel would be drawing directly from shore power and NO BATTS, but at the same time charging both Batt Banks? is that my understanding? and BruceK, if you can find out why your guy said (The guy who delivered my boat 600NM from Melbourne to Sydney is a marine electrician, on route he texted me a diagram I don`t fully understand,saying "This is why don`t select "All".) that would be greatly appreciated. there is a reason he made that very clear to you.....thanks again for all the info everyone......it is a BIG help.

Comodave covered the first part, with no battery selected you`d have no 12v.
I checked the "Manual" for my Integrity, built by the same coy which likely built your IG. It says not to set the batt switch to "All" unless charging both batts from one alternator,it doesn`t nominate selecting 1 or 2. Much as my boat delivery guy/marine electrician, said. It`s too long since the delivery to ask him.
I`m selecting 2 when operating the boat, and All when anchored. Why 2 and not one? Dunno. Why All when anchored? It saves drawing lots out of one batt, I draw moderately from both. I have modest solar (180 watts) and periodically run the genset which runs the charger, for cooking etc,I`ve had no problems. Except just after I got the IG36 and found how bad the batts were when I needed the genset/charger to pump amps into them to get started.

 

[harleydude777]

good morning BruceK, so while on shore power how do you have your's set?

PERKO switch set to "OFF" and of course lower one on "shore power" ? and then of course any breakers I would need to switch on for use.

and THANKS everyone for all the feed back, i will find a certified marine electrician this winter during storage to go through everything with me if not for my own peace of mind but for the safety of all, like a few had mentioned. just wish i wasn't 4 hours from the boat so i could spend more time up on her during these down months.

 

[BruceK]

good morning BruceK, so while on shore power how do you have yours set?

PERKO switch set to "OFF" and of course lower one on "shore power" ? and then of course any breakers I would need to switch on for use.

.

In the marina, I set the main switch to "Both". I keep the charger on, so when 240v is available, via genset or shorepower, it can charge. So in the marina, the batts get charge on demand.
But, you have me thinking. That 12V main switch seems to have 2 purposes: One determining where you draw 12v from, another determining where the alternator(s) charge goes while running engines.