[C320-list] Battery Jump Starter

[Jeff Hare]

In my opinion, whether this solution is a good one, really "depends" on what you do.  If you're a day sailor, it'll get you by if your house bank isn't too dead, but it's not really much of a cost savings (if any) and it takes work and attention to detail to be sure that it's recharged when you need it.

The benefits of having actual AGM starting battery is that it will stay charged at the dock and while under power (just like the battery in your car).

If your house bank is really drawn down you may have a serious problem connecting a battery pack to jump the starter.  The reason is that the dead battery where you connect the jumper will want to draw a most of the current available from the starter pack and not allow enough extra to start the engine.

You have to read the C30 test carefully.  The C30 HAD a starting battery.  They replaced the Starting battery with a small one that was mostly dead.  This test is designed to test whether a charger pack when connected to a small dead starting battery will be able to start a C30's engine.  This is different from connecting a charger pack to a very large dead battery.

When you connect a charger pack to the terminals in this situation, it is very different from putting them across a dead 4D with 10x the capacity and expecting there to be enough left over to run the starter.  It might work, but chances are it won't when you really need it.  

On the other hand, if you had a starting battery in the C320, and it died and your house batteries were also dead, then you can easily isolate the house batteries (with the A-B-Both switch), so in this case, it's very much like jump starting a car and the charger pack will probably work fine. ...but then you had a starting battery already that should only be there for starting the engine...

Also remember that if you play games trying to start your engine using only the charger pack without the main batteries connected, you risk blowing your alternator diodes if you accidentally remove the charger pack for an instant, like when you try to reconnect the house bank so that it'll recharge those while under power.

So... In my mind, it's too complex to say "it'll always work".

Good luck!
-Jeff



-----Original Message-----
From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of sailorlew at aol.com
Sent: Monday, September 28, 2015 4:17 PM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Battery Jump Starter

Here's results of a test done on the C28 list Lew


 https://groups.yahoo.com/neo/groups/catalina28/conversations/topics/15796

 

 

-----Original Message-----
From: Jeffrey Brown <oceanblues at mac.com>
To: Catalina C320 List List <C320-List at Catalina320.com>
Sent: Mon, Sep 28, 2015 4:10 pm
Subject: [C320-list] Battery Jump Starter


After speaking with Dick last week (thanks again Dick) he told me about his backup battery installation for starting the motor should he drain his two 4D batteries.  It sounds like a great setup but a bit beyond my technical capabilities at this time.  However, I was wondering if I could simply use one of those car battery jump starter units, would that work in a pinch as well?  If so, where would I connect it to jump start the engine?  Having a battery backup system for our needs would be for the few trips a year to Catalina.  Our local sailing, when I’ve accidentally drained the battery we’ve been able to just sail back to the slip….of course if there was no wind we would have been in trouble.


Jeff Brown
"Out of the blue" Dana Point, CA
Catalina 320, Hull
78
(949) 350-5123
oceanblues at mac.com