What type of house battery is best?

Batteries, Generators, Solar, Wind and Electronics
Mike Holibar
Posts: 174
Joined: Mon Jun 01, 2009 12:41 am

Re: What type of house battery is best?

Post by Mike Holibar »

Thanks for the comprehensive reply Dean.

I think we can get Optima batteries here under the Century brand and a crusing buddy an electrician also suggested Optima. I picked up that 14V is about the maximum sensible voltage for charging so I can set the regulator on the alternator to that fairly easily. But as there are times when we are motoring for 12 hours or more I have some worries about over charging. Essentially I am looking to maximise the rate of charge in order to minimise engine use when the engine is run purely for charging house batteries. It seems that a high rate of charge can be achieved by stepping up the voltage for a time but there must be some means to reduce or stop the charge when the batteries reach full charge. In the system I have, after a minute or two running the engine, both the start and windlass batteries will be fully charged and the VSRs will have switched the charge to the house bank. I am not sure if the VSRs switch off the charge to the start and windlass or whether it just parallels the house batteries for charging. Assuming the former, the solution might be to place a "smart" charger in the circuit, supplied from the VSR that switched to the house bank, and utilise this to charge only the house bank. Does this make sense? Am I getting somewhere near a workable solution?

Thanks,
Mike Holibar
S/V Fyne Spirit of Plymouth (Freedom 39PHS-1989)
Lyttelton
New Zealand

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rvivian
Posts: 190
Joined: Sun Feb 21, 2010 2:08 pm

Re: What type of house battery is best?

Post by rvivian »

Mike -

I think that most recommend directly charging the house bank from the alternator (with a smart external regulator to match the charging voltage to the charged state of the house bank) and then charging the starting battery and the windlass battery once the house bank is charged. The charging for the downstream batteries can be controlled by the switches you have or by auxiliary chargers like the Duo-Charge or Echo-Charge units.

Generally the smaller windlass battery and starting battery are not deeply discharged to begin with and they probably should not be subject to the higher charging rate that the house battery bank can accept.

rvivian
Heart's Desire
Freedom 30
Shelton, WA

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OldRover
Posts: 60
Joined: Tue Feb 08, 2011 6:25 pm
Location: New York, NY

Re: What type of house battery is best?

Post by OldRover »

Mike,
Motoring for more than a few hours definitely could get bad without some means of preventing a higher voltage (over 14.5V) from overcharging batteries. Manual switch, possibly your VSRs (I'd check the spec sheet, what's the model?), and/or charging units.
I agree with rvivian's response (although a bit short and concise :) ).

-Dean
'82 F39 ph

Mike Holibar
Posts: 174
Joined: Mon Jun 01, 2009 12:41 am

Re: What type of house battery is best?

Post by Mike Holibar »

Rvivian,

the local practice is start batt first and then others. The setup on Fyne Spirit was originally round some kind of smart charger which the po took out. I started off with manually adjusted regulator and manual switching which system resulted ultimately in gassing the batteries and blowing diodes in the alternator. First time the alternator was repaired, second time it had to be replaced. So, having a new alternator I got the local experts down to set up the system with VSRs, so at the moment my alternator and batteries are safe but the charge rate for the house batts is frustratingly low. All the auxiliary chargers are connected to the house bank. I can see the merit in connecting the alternator that way round too but as the VSRs operate at 13.5 volts, if I set the regulator to say 14.5, the VSRs will switch almost as soon as the house bank goes on charge (I think) so I think I would not be much further ahead. Maybe some kind of dual charger would be the answer, supplied by the alternator and providing conservative charge to start and windlass, with a more aggressive charge for house. Then I wouldn't need the VSRs or any of the work done last year. Story of my life :roll:
Mike Holibar
S/V Fyne Spirit of Plymouth (Freedom 39PHS-1989)
Lyttelton
New Zealand

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rvivian
Posts: 190
Joined: Sun Feb 21, 2010 2:08 pm

Re: What type of house battery is best?

Post by rvivian »

Hi -

Maybe different there, and I'm no expert, but have a look at one of the alternator manuals online at:

http://www.balmar.net/manuals.html

Look for the proposed wiring diagram showing the smart regulator used in conjunction with the Duo Charge.

I am just finishing wiring up my new battery banks and alternator in accordance with the diagram.

The house battery will be charged by the alternator at its optimum charge rate and then the Duo Charge will charge the starting (and windlass) batteries once the house battery is brought up to snuff.

Hope this helps.

rvivian
Heart's Desire
Freedom 30
Shelton, WA

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