I have 2 house batteries and 1 starting batttery. I try to remember to switch to the start battery under power and then switch to house when i shut off the engine, but i sometimes forget to switch back to house after shutting off the engine.. What is the problem with using the house batteries for starting and general usage, and keeping the remaining battery just as a backup if needed?
Nothing sounds like a good idea. Charlie
The engine doesn't care which battery you use. It is the rest of the stuff on the boat.
The issue I was having was losing the chartplotter when starting the engine (temp low voltage). Ok for home port, not so much entering an unknown port or if you have a guest driving. I have a separate start circuit with its' own battery switch. Start battery always starts the engine, house bank runs everything else. In emergencies, I can start with the house, or run the house with the start.
Quote from: SPembleton on May 08, 2017, 04:02:24 AM
I have 2 house batteries and 1 starting batttery. I try to remember to switch to the start battery under power and then switch to house when i shut off the engine, but i sometimes forget to switch back to house after shutting off the engine.. What is the problem with using the house batteries for starting and general usage, and keeping the remaining battery just as a backup if needed?
It sounds like you don't have an ACR installed. You should not have to turn off the start battery when the engine is turned off.
Steve
No problem. Read the 101 topics -- and the analysis by MaineSail of what it takes to start a diesel. There is no need for a "start" battery -- instead think of it as an "emergency reserve" and just use your bank for starting.
Are you on a mooring or tied to shore power? If the latter, your emergency battery will alyways be topped off and so (generally) you don't need to switch to charge it. KISS
ken
Quote from: SPembleton on May 08, 2017, 04:02:24 AM
.. What is the problem with using the house batteries for starting and general usage, and keeping the remaining battery just as a backup if needed?
Quote from: SPembleton on May 08, 2017, 04:02:24 AMWhat is the problem with using the house batteries for starting and general usage, and keeping the remaining battery just as a backup if needed?
If you have an automotive type battery as a start battery, it makes sense to use the start battery for starting and save the Ah for the house bank since the start battery is not a deep cycle. If the start battery is deep cycle, like the house, then it doesn't make too much difference but you'll do more switching. I like to set my house bank to 1 on the 1-2-B and leave it there. The start battery switch is turned off only when leaving the boat for an extended time or working on the engine.
READ THE 101, and learn how many "A-Hs" you use up starting the engine!!
How does being a non D.C. battery's an argument for using it for every start? Without sensitive equipment it's difficult to even MEASURE the amt of energy used to start the engine!!!
Quote from: mark_53 on May 08, 2017, 08:32:36 AM
If you have an automotive type battery as a start battery, it makes sense to use the start battery for starting and save the Ah for the house bank since the start battery is not a deep cycle.
Quote from: KWKloeber on May 08, 2017, 08:43:18 AM
READ THE 101, and learn how many "A-Hs" you use up starting the engine!!
How does being a non D.C. battery's an argument for using it for every start? Without sensitive equipment it's difficult to even MEASURE the amt of energy used to start the engine!!!
It's a matter of using your equipment as it was designed. An automotive type start battery is designed for short bursts of high energy. If you have spent the time, energy and cash to install a start battery, then why not use it? If it just sits there, your not getting use. Boaters look for all sorts of ways to conserve power so why not use the equipment you have? The OP was concerned with all the switching he was doing. I'm saying the switching is not necessary if you have the right setup. Better to keep whatever amount of Ah the starting battery requires in the house bank where greater demand will be and used how the house bank was designed.
Again, think designed for RESERVE, not
start!!
Do you know how many A-Hs your saying you are "keeping" for the bank???? Keep this Fact based -- look it up.
Ok, I'll make a counter argument. Keeping the third battery for "emergency" -- what kills a battery? Number of cycles, correct? So the less you use it the greater chance it will be "like new" when you need it for an emergency.
You said "if it's an automotive rather than deep cycle battery." What difference would that make using your argument of "saving" amp hours in the house bank? The third battery is irrelevant in that logic thread.
Use the facts to make your case..... starting uses LESS than 1/10 amp hour. Out of say a 150 ah bank. Save that? Really? That's LESS THAN 0.000667 percent used. Putting it into perspective, that's equivalent to stopping at grocery store A versus grocery store B to save one penny on a $15 steak. Your steak, your choice.
Steve, just do what you proposed. You're thought process is absolutely "right on" for your situation/set up.
kk
Quote from: mark_53 on May 08, 2017, 09:33:07 AM
Quote from: KWKloeber on May 08, 2017, 08:43:18 AM
READ THE 101, and learn how many "A-Hs" you use up starting the engine!!
How does being a non D.C. battery's an argument for using it for every start? Without sensitive equipment it's difficult to even MEASURE the amt of energy used to start the engine!!!
It's a matter of using your equipment as it was designed. An automotive type start battery is designed for short bursts of high energy. If you have spent the time, energy and cash to install a start battery, then why not use it? If it just sits there, your not getting use. Boaters look for all sorts of ways to conserve power so why not use the equipment you have? The OP was concerned with all the switching he was doing. I'm saying the switching is not necessary if you have the right setup. Better to keep whatever amount of Ah the starting battery requires in the house bank where greater demand will be and used how the house bank was designed.
Steve, see
https://forums.sailboatowners.com/index.php?threads/engine-starting-video-real-world-amp-load-data.102027/
ken
Quote from: KWKloeber on May 08, 2017, 10:32:25 AM
Again, think designed for RESERVE, not start!!
Do you know how many A-Hs your saying you are "keeping" for the bank???? Keep this Fact based -- look it up.
Ok, I'll make a counter argument. Keeping the third battery for "emergency" -- what kills a battery? Number of cycles, correct? So the less you use it the greater chance it will be "like new" when you need it for an emergency.
Based on your energy numbers, one would never fully cycle the start battery since it is immediately recharged. If you never use it, your getting no use of the asset you purchased and when it truly is an emergency, you will be hoping it works. By using it, your 1) not depleting your house bank, 2) your using your asset, 3) your confident your start battery will work when called upon and 4) It will isolate your instruments from starting transients.
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Quote from: KWKloeber on May 08, 2017, 10:32:25 AM
You said "if it's an automotive rather than deep cycle battery." What difference would that make using your argument of "saving" amp hours in the house bank? The third battery is irrelevant in that logic thread.
The OP question had to do with starting off the house bank and reducing switching. Either battery type would have no problem starting the engine and the total Ah capacity of the boat is fixed. If the start/RESERVE battery is a deep cycle, it would not make much difference which battery bank was used for starting since the reserve could be depleted for house loads as it was designed. Not so with an automotive start battery. If the START/reserve is an automotive type start battery, one would not be happy with its deep cycle performance. With either type battery, I would still start off the start battery to get the use out of it, have the confidence it's working and, isolate starting transients to your instruments. I would not like to flip a switch to accomplish that and is not necessary.
Quote from: KWKloeber on May 08, 2017, 10:32:25 AM
Use the facts to make your case..... starting uses LESS than 1/10 amp hour. Out of say a 150 ah bank. Save that? Really? That's LESS THAN 0.000667 percent used. Putting it into perspective, that's equivalent to stopping at grocery store A versus grocery store B to save one penny on a $15 steak. Your steak, your choice.
Savings add up. Also, if you use an ACR, the two banks are combined for a period of time after charging thus getting additional use of the start battery.
Thank you all for your insights and experience. I am having some of the same problems that Ken Juul mentioned losing power for the chartplotter (actually i lose my bluetooth wind sensor first when power drops.) I leave my boat in a slip and on shore power 24/7. I am going to be really careful about starting on the start battery and switching to house as soon as i shut down the engine, and see if it affects the length of time before i lose power for the wind sensor. If there is no difference, I will just keep the "start battery" as emergency as KWKloeber and Mainsail suggests. If it does make a difference i will just have to be more disciplined. In any case, i do appreciate everyones input!
Steve,
You've hit one nail squarely on the head. If you're tied to a shore charger, your battery and charging set up is "correct", it doesn't make a rats butt difference on the "start" versus "reserve" because your reserve will be fully charged every time you leave the dock.
The argument of "getting use out of "a piece of equipment is a false argument. You get use out of which ever battery you use. A reserve battery is like a fire extinguisher you buy it for when you need it not to use it every time you want to put out a campfire. If you have a reserve tank of propane, you don't keep using it up just to "get use out of it". If you have a reserve fuel tank on a plane you don't keep using it to "get use out of it" (Other than to keep fuel fresh).
It's a different situation if you're on a hook, and have an ACR to make sure your topping off the "reserve" battery every minute you motor.
I'm not really sure how losing power to the Bluetooth makes a difference with which battery you start on? Elaborate?
Ken.
Quote from: SPembleton on May 08, 2017, 01:56:52 PM
Thank you all for your insights and experience. I am having some of the same problems that Ken Juul mentioned losing power for the chartplotter (actually i lose my bluetooth wind sensor first when power drops.) I leave my boat in a slip and on shore power 24/7. I am going to be really careful about starting on the start battery and switching to house as soon as i shut down the engine, and see if it affects the length of time before i lose power for the wind sensor. If there is no difference, I will just keep the "start battery" as emergency as KWKloeber and Mainsail suggests. If it does make a difference i will just have to be more disciplined. In any case, i do appreciate everyones input!
If you use a Blue Sea SiACR (start isolation) along with running your chart plotter off your house and start off the start battery you will not have the problem of loosing your instruments when you start. And you won't have to through any switches
Quote from: KWKloeber on May 08, 2017, 02:13:22 PM
I'm not really sure how losing power to the Bluetooth makes a difference with which battery you start on? Elaborate?
Ken.
I did deteemine that when the voltage drops to 10.8v the bluetooth gWind sensor stops working.
I just want to ensure that starting on the start battery or starting in the house battery makes no difference on my boat. I agree with you in theory, but pos could have done all kinds of things from 1986.
Quote from: SPembleton on May 08, 2017, 04:02:24 AM
What is the problem with using the house batteries for starting and general usage, and keeping the remaining battery just as a backup if needed?
If you have a 1/2/B switch there is nothing wrong with that and it will lead to less human induced errors... if you are trying to avoid brown outs, that is more complex, can happen regardless of which bank of a 1/2/B switch you start off and may have numerous causes. To keep it simple start the motor then boot instruments. If you want a more complex solution those exist too.
Quote from: mainesail on May 08, 2017, 04:04:53 PM
Quote from: SPembleton on May 08, 2017, 04:02:24 AM
What is the problem with using the house batteries for starting and general usage, and keeping the remaining battery just as a backup if needed?
To keep it simple start the motor then boot instruments. If you want a more complex solution those exist too.
So when your under sail using instruments and you need to restart the engine, you lose your instruments? Not an optimal solution. Tell him about start isolation.
There is only start isolation if you have a dedicated start battery on its own circuit. SI does not apply to a 1/2/B which, by his description, he seems to have..
Mark, that is NOT the situation. I start the engine, instruments work fine. After i am out to the big lske, i shut off the engine, instruments still work. I try to remember to switch from start to house. Instruments still work. After a few hours sailing, voltage drops to 10.8v and the gWind bluetooth sensor stops working. I usually continuing sailing. After a while i return to port, i try to remember to switch back to my stsrt battery, start my engines and the gWind starts working again.
I have replcaced all 3 batteries. I am now going to test to see if the voltage drop has anything to do with which battery i use to start the engine.
Quote from: mainesail on May 08, 2017, 05:37:02 PM
There is only start isolation if you have a dedicated start battery on its own circuit. SI does not apply to a 1/2/B which he has...
I believe that's what he says he has, "2 house batteries and 1 start battery". and his instruments are crapping out when using the house bank to start.
Quote from: SPembleton on May 08, 2017, 05:43:28 PM
Mark, that is NOT the situation. I start the engine, instruments work fine. After i am out to the big lske, i shut off the engine, instruments still work. I try to remember to switch from start to house. Instruments still work. After a few hours sailing, voltage drops to 10.8v and the gWind bluetooth sensor stops working. I usually continuing sailing. After a while i return to port, i try to remember to switch back to my stsrt battery, start my engines and the gWind starts working again.
I have replcaced all 3 batteries. I am now going to test to see if the voltage drop has anything to do with which battery i use to start the engine.
Your house bank is toast or you have a bad or loose connection or grossly undersized wire.Your batteries should only briefly drop below 12.1V under short duration high current loads otherwise you should never see them drop below 12.1V and especially not under just sailing instruments after a few hour sail... you need to measure the actual battery voltage at the terminals when you are seeing 10.8V.
Quote from: SPembleton on May 08, 2017, 05:43:28 PM
Mark, that is NOT the situation. I start the engine, instruments work fine. After i am out to the big lske, i shut off the engine, instruments still work. I try to remember to switch from start to house. Instruments still work. After a few hours sailing, voltage drops to 10.8v and the gWind bluetooth sensor stops working. I usually continuing sailing. After a while i return to port, i try to remember to switch back to my stsrt battery, start my engines and the gWind starts working again.
I have replcaced all 3 batteries. I am now going to test to see if the voltage drop has anything to do with which battery i use to start the engine.
Okay, I see. The house cable run to start is probably longer than the start battery's. I don't understand why your switching from start to house all the time.
You may be wired differently then me but my start battery starts the engine regardless of where the 1-2-B switch is set.
Quote from: mark_53 on May 08, 2017, 06:06:55 PM
my start battery starts the engine regardless of where the 1-2-B switch is set.
If that is your only battery switch it should not behave like that...
Quote from: mainesail on May 08, 2017, 06:13:17 PM
Quote from: mark_53 on May 08, 2017, 06:06:55 PM
my start battery starts the engine regardless of where the 1-2-B switch is set.
If that is your only battery switch it should not behave like that...
There is a separate battery switch.
For what it's worth -- I have a 4 x T105 house and 1 650 CCA as a "reserve". The house is on position 1 and the "reserve" is on position 2 of the 1-2-B selector switch. I can start on position 1, 2 or B and the instruments, chart plotter, radar, and network continue to function as intended. The only time I had an issue after starting is when I switched from position 2 to position 1 by going through the "OFF" position. Operator error not system error.
Energy consumption-- After a full day sailing with instruments and chart plotter on, fridge, plus starting the engine twice, my Smartgauge reads ~98% charge for the house bank.
Jon
Are you saying you blew the diodes going through "off"?
I'm pretty sure he was saying that by inadvertently going thru OFF he briefly lost power to his instruments, etc (as expected).
I have previously looked at his wiring diagram and his alternator goes directly to his house bank, so going thru OFF wouldn't impact his alternator.
Jeremy has it correct. The AO connects to the house bank. The 1-2-B switch only chooses which bank is being used. By accidentally rotating the switch through "OFF" I shut the power off. Duh. I should have rotated through "B".
Gotcha! DUH! Thanks for the clarification Jon and Jeremy,
Of course that episode speaks to what RC says with a set up like Steve has. (Paraphrased) "Just leave your selector on the house bank and avoid the well intended (insert brother-in-law, guest, etc. as appropriate) human intervention that can blow your alternator diodes."
Quote from: Jon W on May 09, 2017, 08:08:00 AM
Jeremy has it correct. The AO connects to the house bank. The 1-2-B switch only chooses which bank is being used. By accidentally rotating the switch through "OFF" I shut the power off. Duh. I should have rotated through "B".