Wiring up a battery switch

[Vega1447]

Hi all.
I have two 75Ah batteries wired in parallel serving both starter motor and lights etc.
I plan to rewire with a 1-2-both-neither battery switch so that I can have both batteries disconnected when away from the boat.
Question: I have a solar panel that keeps batteries topped up, even in winter. At present I have the panel wired into the main fuse board.

Any advice as to how to wire the (low current less than 0.5A) positive terminal so that both batteries stay topped up while battery switch is in off position?

I'd like to keep the two batteries separate - so wiring the solar charger to the batteries in parallel would defeat the point of having a 1-2-both-neither battery switch.

Am I missing a point here?

Thanks.
John V1447 BreakawayJohn Kinsella
Mathematics and Statistics Dept
University of Limerick

Phone 0035361202148
Web jkcray.maths.ul.ie

 

[wemccourt]

Buy a 2nd Solar panel and connect one to each battery with Alligator clips when
not using the boat.

K. I. S. S. reigns supreme.

Bill McCourt
Reston, VA

________________________________
From: John.Kinsella John.Kinsella@...
To: AlbinVega@yahoogroups.com
Sent: Fri, November 5, 2010 6:21:13 PM
Subject: [AlbinVega] Wiring up a battery switch


Hi all.
I have two 75Ah batteries wired in parallel serving both starter motor and
lights etc.

I plan to rewire with a 1-2-both-neither battery switch so that I can have both
batteries disconnected when away from the boat.

Question: I have a solar panel that keeps batteries topped up, even in winter.
At present I have the panel wired into the main fuse board. Any advice as to how to wire the (low current less than 0.5A) positive terminal
so that both batteries stay topped up while battery switch is in off position?

I'd like to keep the two batteries separate - so wiring the solar charger to the
batteries in parallel would defeat the point of having a 1-2-both-neither
battery switch. Am I missing a point here?

Thanks.
John V1447 Breakaway

John Kinsella
Mathematics and Statistics Dept
University of Limerick

Phone 0035361202148
Web jkcray.maths.ul.ie

 

[btfag0s]

Hi John,

I've had a similar arrangement for many years.

1/2/both switch is wired as expected.

I have a wind generator that feeds a pair of diodes that attach on the
battery side of the 1/2/both switch (schottky diodes if I remember
correctly, cost coppers). The output from the wind generator (regulated)
charges both batteries, but nothing crosses over, and nothing else in the
boat is live when the 1/2/both switch is in the 'none' position.

By the way, I also keep a bilge pump wired up directly through a float
switch to one of the batteries. Worst case scenario is that the switch jams
on and the pump's been working a lot while I've been away, but only ONE
battery is completely flat.

Hope that helps,

Alisdair

 

[pjacobs55]

John,
I have two battery banks, one house and one engine, that I have on a 1-2-All switch. They're hooked up to my solar panel(s) with a Flexcharge USA PV7D Battery Controller

http://www.flexcharge.com/flexcharge_usa/products/pv7/pv7.htm

that charges both banks simultaneously without connecting them together. I have the controller hooked directly to each bank, so that even in the "off" position on the main switch they're still charging.
It also works to prevent the batteries from overcharging. It's run well for three years so far, and was a doddle to install!

Hope this helps,
Peter
#1331 'Sin Tacha'

 

[tim_klynn]

I installed this controller:http://www.morningstarcorp.com/en/sun-saver-duo
It allows charging for 2 batteries. I like the read out. I can check each battery voltage, the current output from the panel (my PV panel swivels so I use the output to help aim it at the sun) and it has the room temperature, which is mainly used when my girlfriend says that it is "freezing in here" and I can reply, "no it's not, honey,-look it's 48 degrees!". It kept the batteries charged up over the winter when the boat was on the hard and behind a hill from much of the direct sun.

I've also got the 1-2-both-off switch. I think I wired one lead directly to each positive battery terminal, bypassing the 1-2 switch.

I've got it on a 20 watt panel. -Tim

 

[groundhogyh]

Tim,
how much does that gadget cost.
rb

 

[tim_klynn]

I found one fairly cheap on ebay, but a quick google search for "morningstar sunsaver duo" turns up some from $135-190. As usual, places with "green" or "eco" in the store name tend to be more expensive.....