Buffering 12V power to electronics with small AGM battery

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Buffering 12V power to electronics with small AGM battery

Postby bstronger » Wed Mar 10, 2010 6:51 pm

Anyone have any experience with this? What wiring makes most sense? I am considering doing this for new N2K mfd and vhf on my flybridge. Thanks, Brian
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Re: Buffering 12V power to electronics with small AGM battery

Postby elnav » Wed Mar 10, 2010 9:44 pm

Brian if you add such a battery you will need to give thought to charging the battery. If you choose th use only a diode be suer it is of the Schottky type to minimize voltage drop and thus leaving the battery undercharged.
If adding a small 10 amp charger be sure it is a smart type that goes into float and does not damage the battery.
Arild Jensen
Custom electrical design for cruising boats
Telephone: 250 998 4474
Site: http://www.electronicnavigator.com
Email: mailto:2elnav@netbistro.com
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Re: Buffering 12V power to electronics with small AGM battery

Postby bstronger » Wed Mar 10, 2010 10:30 pm

Arild, Thank you. I am considering an Enersys NP18-12B sealed battery [17.2 ah / 20 hr rate] and a Battery Tender waterproof 0.8 amp smart charger/maintainer. I plan to also have the battery switchable to charge from my house bank if needed when I am actually underway [and my engine alternators are keeping the voltage up] and thereby eliminate the diode altogether. Do you see any issues with this plan? Brian
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Re: Buffering 12V power to electronics with small AGM battery

Postby elnav » Thu Mar 11, 2010 6:02 am

Yes. Without the diode any sort of fault in your main system would rapidly drain you smaller battery.
You need to isolate the console battery from being drained by the rest of the house circuits.
Arild Jensen
Custom electrical design for cruising boats
Telephone: 250 998 4474
Site: http://www.electronicnavigator.com
Email: mailto:2elnav@netbistro.com
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Re: Buffering 12V power to electronics with small AGM battery

Postby bstronger » Thu Mar 11, 2010 8:34 am

Arild, Diode for sure. One more question - I am considering
goIng with a larger charger, 2/4/8 amps, that also does pulse
desulfation. Is that ok for a sealed agm battery?
Thank you, Brian
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Re: Buffering 12V power to electronics with small AGM battery

Postby elnav » Thu Mar 11, 2010 10:57 am

Yes that should be okay. Is this one of the Pulsetechs or has someone else entered the market with such products.
Arild Jensen
Custom electrical design for cruising boats
Telephone: 250 998 4474
Site: http://www.electronicnavigator.com
Email: mailto:2elnav@netbistro.com
elnav
 
Posts: 65
Joined: Fri Apr 10, 2009 4:54 pm

Re: Buffering 12V power to electronics with small AGM battery

Postby bstronger » Thu Mar 11, 2010 3:14 pm

Arild, The pulse charger/maintainer I have selected is the Batteryminder model #12248 which is described here:
http://www.batteryminders.com/batterych ... 16133.html
My choice was primarily based on the higher possible charging rate as I still do not know how high my total current will be when I am finished adding components.
I will also have the house current available to the battery via a Guest gst-2501 battery isolator and switch for backup.
The battery is an Enersys/Yuasa NP18-12 Battery found here:
http://www.pacificbattery.com/np18-12.html
Thank you for your good advice. Any further suggestions - wiring, switches, connectors etc. - are appreciated
Brian
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