Battery management/perko switches

[mjohnh]

I have just purchased a 2005 Albin 28 TE...nice boat.....315 yanmar. and only 460 hours....no genset......does have a house battery and starter battery and inverter.

I want to make certain that the starter battery always has power and is not drained down by refrigerator, etc.

I read about "Perko" switches. Where are they likely to be? Are their function to isolate the batteries and keep the starter battery preserved for starter use only?

My great fear is being on the water and not being able to start the engine due to low battery. By the way, the starter battery is new (I don't know the brand or amps, but it is huge and supposedly was a $1000.00 item) Boat won't be delivered until 8/25.

All of this is factory installed and in very good shape. I just need a primer on battery management to avoid an embarrassing problem without a generator. The 2 prior owners have not seen the need for a generator.

Any reply will be greatly appreciated.

[elad]

The battery switch is under the step down into the cabin. You have choices of off - 1 - 2 - both. You may want to check to see if "1" is your house battery as mine is with "2" being the house battery. I have my inverter connected to "2" only so the only way to drain the starter battery is with the switch in the both position.

I recommend putting the switch to "1" when starting and "both" once the engine is running so that both batteries charge. When the engine is not running I switch to "2" only so as not to drain the start battery. Never leave the switch on both when the engine is not running. Not only do you risk draining the start battery but you will drain both batteries down to the level of the weakest one.

[DougSea]

Elad sums up a "normal" installation quite well above.

I do want to add that this is an area where many owners have made changes/upgrades. So your boat may or may not fit within the instructions above.

Battery cables tend to be fairly easy to trace, so I'd recommend getting aboard your boat with someone with 12v system knowledge and figuring out what you ACTUALLY have for a battery switch configuration.

Good luck!

[Carl]

I think Elad had a typo in his description. "1" is his start battery, "2" is his house battery. Also a search on this topic will tell you to never go to the off position while the engine is running.

[Tree]

I leave both batteries on at all times. Pretty sure the alternator on the Yanmar is a split diode charge or something along those lines so the battery with the greatest need for charge is the one that is charged?

Ultimately, unless you are leaving the refrigerator on for long periods over 24 hours without any charge, you shouldn't see an issue. We have the old norcold fridge and also an inverter aboard for the microwave and have yet to see any issue with the batteries. We have deep cycle batteries at 180 amp hour and the cca is 1040 I think? They are capable of cranking the engine over anyway!

When I am berthed in the marina I do plug in to shore power. I've changed over to a sterling power smart charger that will occasionally "cycle" the batteries albeit only a 10 amp system. The batteries appear to be in top form.

[Sven_G]

On our winter boat (Senta) we have a Xantrex Echo Charger http://www.xantrex.com/power-products/p ... arger.aspx for the starter battery.

That unit has a lot of detractors and I won't argue against them. The theory is nice and so far it's worked great for us. The selector switch is always on the house bank and when there is charge flowing it will top up the starter battery while also filling the house bank. If the house gets run down the starter battery is there, fully charged by just switching to it.

On Bali (our A25) we always run the engine with the selector set to all. At anchor we set the switch to the house bank. The main thing I don't like about this set-up is that I'm not sure how the charger circuitry is set up (smart charger or whatever) so I don't know if the charge levels are optimally maintained or if one bank might be overcharging. For right now we're not sweating it too much because it's only 210 Ah total so it is not a bank-breaking investment if we're mistreating one bank.

[mjohnh]

Thanks everyone. I believe that 1 is the house battery and 2 is the starter battery. The switch is on 2.

(the next statement I have not thought through so any corrections will be appreciated) I BELIEVE that it is best to leave it on 2, and there

is never a reason for it to run on 1, because when the engine is running both house and starter battery are getting charged off of the alternator

I cannot think of a reason to run it on 1....if anyone out there has a suggestion on this, I would appreciate another response.

Thanks again.

[Jay Knoll]

You might want to take a look at this product

http://www.bluesea.com/products/7650/Ad ... Kit_-_120A

With one of these installed you don't have to worry about switching between "All" when running and the house bank when at anchor/dock.

I would have someone check the wiring on the switch, I'm not certain that both batteries would be charging when the engine is running if the switch is just set to 2. If you have a battery panel with a meter that allows you to check the charge on both batteries you can check if there is a difference in the state of charge on the two banks when the engine is running and the switch is just set to "2". I would be concerned that you would be slowly running down the starting battery, thinking that you were charging it while you were underway when in fact all you would be charging would be the house bank.

[Sven_G]

I'm not certain that both batteries would be charging when the engine is running if the switch is just set to 2.

I agree. If it somehow does charge both banks with the selector set to just one there must be some circuitry already in place to do that, similar to the Xantrex or Bluesea devices mentioned above. If I'm wrong I'm most eager to learn how it works

[mjohnh]

Battery life issue.....Serenity Now was pulled for winter heated storage 2 weeks ago. When I tried to start it to motor over to the marina, the batteries were dead due to a failure of the shore power...for as long as 2 to 4 days. The boat was started with the aid of a booster and it was hauled and put in storage. The batteries are AGM and less than 2 years old. I called the battery supplier and they advised charging them; then disconnecting the negative; then repeating the process in 90 days. I just got a note from my marina that said that the batteries are dead and need to be replaced. ( I was warned that this marina was ....shall we say...prone to "stuff").....What would be a quick way for me to check if the batteries are "dead" or just need recharging as suggested by the battery supplier? My boat has a charger built in. If the batteries sit all winter (in Michigan) even though in heated storage and I try to charge them next April with the built in charger, what is your best guesses as to the result. I plan on buying a portable power pack to keep on the boat as one of my great fears is being out on Lake Michigan and have dead batteries.

[Pitou]

Battery life issue.....What would be a quick way for me to check if the batteries are "dead" or just need recharging as suggested by the battery supplier?

The best and only way to test the batteries is to find someone who can "Load Test" them after you put a full charge on them. Most repair shops have this capability or better yet find a local battery shop to do it.

[mjohnh]

Thanks...

[mjohnh]

New problem.....Battery not enough to start the engine after 10 days on A/C with battery charger "on"..........I "dumbly" left the nav light switch "on".........seems that the battery charger would push more amps/ohms/volts in than the nav lights would take out..............sort of academic, but I will soon find out as I have just left the boat with the A/C and battery charger on and the nav lights "off"............any thought on this as being enough to drain the batteries?.....the Perko was on "both".....

Thanks.....

[Russell]

Yes, you should be able to calculate the drain of the nav lights, probably in the milliamp range and the charger should be 10 amps minimum. My guess is that the charger is not working or not wired correctly. Check the voltage at the batteries with the charger on and off. I leave my battery switch in the off position when I leave the boat for piece of mind. The charger and the bilge pumps still work and I don't have to worry about what was unintentionally left on.

[mjohnh]

Great idea....I will do that in the future........by "battery switch" I am assuming that you mean the "Perko" under the step?

Also, where is the battery charger? I know where the inverter is....just above the batteries under the battery hatch cover between the helm seat and the passenger seat.........but, i do not know where the battery charger is.....as you point out maybe it is defective......if it is, how do you narrow down the "defect" and the "fix"????

Thanks, again.