[C320-list] Another battery-related question

[Robert Seastream]

Jeff, I'm surprised Dean had but one 4D battery.  Perhaps a PO choice,  
facing replacing both?  I thought all 320's came with two 4D's, else  
why a battery switch.

Bob Seastream, Intuition # 906

On Sep 6, 2011, at 4:31 PM, Jeff Hare wrote:

> This should work. If the 1-2-both switch is acting like an on/off  
> then the new battery probably wasn't hooked up quite right.
>
> In proper hookup, both battery negatives should be connected  
> directly together. One heavy red from one battery positive should go  
> to the "1" post of the switch, the second heavy red should go to the  
> "2" post on the switch. The "C"ommon post of the switch goes to the  
> starter and the "house" power panel.
>
> The 4awg red cables are usually shore power charger and windlass  
> power.
>
> Check carefully for the 3 foot section of black 2/0 gauge cable that  
> is the key ground between both batteries. If the prev owner only had  
> one battery, he may have also disconnected that jumper and left it  
> in the compartment somewhere. You need that.
>
> -jeff
> -jeff
>
> Dean Vermeire <dean at vermeire.us> wrote:
>
> Hi Jeff,
>
> I'm familiar with the wiring that you've described. Makes perfect  
> sense.
>
> In my case, there was only one battery to start with. Both positive
> cables, as well as the two heavy ground cables and the smaller ground
> cable were connected to the one 4D battery. There was no jumper.
>
> When I replaced the 4D battery with a group 27 battery, I found that I
> had to connect all cables the way I had found them, which sounds
> obvious. What surprised me was that I couldn't have one battery
> connected to just one set of cables with the switch set to that  
> battery
> and have the engine start. Basically, the two battery switch really
> only acts as an on / off switch when both sets of cables are connected
> to only one battery.
>
> On 9/6/2011 10:14 AM, Jeff Hare wrote:
>> We can only speculate here without some pictures of the wiring  
>> you're referring to, but what may have happened was that you didn't  
>> get all the grounds connected.
>>
>> The starter/engine ground connects via heavy cable to the aft most  
>> battery, then a jumper continues to the forward battery. The  
>> forward battery typically has the windlass ground attached also. Is  
>> it possible you didn't get the heavy ground between the batteries  
>> connected? All grounds need to be connected.
>>
>> Jeff
>>
>> Dean Vermeire<dean at vermeire.us> wrote:
>>
>> Hi Folks,
>>
>> You'd think that all possible questions have been asked by now, but I
>> came up with another this weekend. When we got out to the boat for a
>> nice long weekend and were ready to head out, the engine would not
>> start. The batteries just didn't have enough juice for it.
>>
>> This is the first time I have had to get at the batteries on this  
>> boat,
>> so please forgive the stupidity here! When I got at the batteries, I
>> found that there was really only 1 there - a 4D truck battery (which
>> others have recommended lately). That's fine. Nice to know. I ran
>> over to the marina store (the only place open on Sunday) and bought a
>> Group 27 Deep Cycle battery. I will probably put in a 4D again, since
>> the battery tray fits a 4D perfectly.
>>
>> When I hooked up the new battery. I only connected one set of battery
>> cables. I put the switch on "1". The radio, instruments, VHF, etc.  
>> all
>> worked fine, but the engine did not turn over. Not even a click. I
>> switched the cables on the battery and put the switch on "2". Same
>> thing. Finally, I put the cables the way I had found them, with both
>> sets of cables hooked to the one battery. I probably put the switch  
>> on
>> "All", although I don't understand what difference it would make. The
>> engine started right up.
>>
>> The boats I have had in the past had two batteries. I made it a habit
>> of switching to just one battery once the engine was off, to make  
>> sure I
>> would have enough power to start up again later. Having both sets of
>> cables on one battery seems to be contrary to that idea.
>>
>> So, why didn't the engine have power when I had just one set of  
>> cables
>> on the battery and have the switch set to that battery number?
>>
>> Humbly,
>> Dean Vermeire
>> Moonstruck II (#847)
>>
>>
>>
>