Do I need a battery disconnect?

[Kymasabe]

I have two batteries on the boat, one for starting and runs all my electronics and the other deep cycle for my trolling motor. I have a few questions. My starting battery slowly looses it's charge over the course of a few weeks. I ususlly put it on a trickle charge for a day before using the boat and it's fine for the trip. Would it help to install a battery disconnect switch? Should the boat have one?
Second question is...how do you charge a deep cycle battery. Hard and fast or trickle charge over long time?

 

[QuadManiac]

Re: Do I need a battery disconnect?

Switch is a good idea because these days so many things still draw small amounts of power, even when turned off. Stereos are the best example. I installed a new one a couple of months ago and was shocked when I measured 2 Amps draw, even with it turned off. Pulling the face plate fixed that one. I could have run the 'switched' line to one of my Aux switches, and that might have taken care of it too, but haven't tried that yet.

Bottom line, switch will eliminate ALL current draw during storage.

For your battery, trickle will always work well and most smart chargers these days can differentiate (or have a setting) between regular and deep discharge batt's and adjust the higher current charge curves accordingly.

 

[Barnacle_Bill]

Re: Do I need a battery disconnect?

Have you checked your motor's charging circuits? Also have the battery load tested. Shorted plates can cause it to drain just sitting there.

 

[drewpster]

Re: Do I need a battery disconnect?

Wet cell batteries can and do self discharge even when disconnected. A battery switch is a good idea for many reasons including isolating the battery from unintended amp draw.
Self discharge occurs most often as a normal consequence of use over the life of the battery. It is not necessarily an indication of a particular problem.
I recommend an automatic charger with a deep cycle setting. Their not as pricey as they used to be, and the deep cycle setting will optimize the charging profile to improve battery life. Not to mention the convenience of hooking it up and forgetting about it.

 

[QuadManiac]

Re: Do I need a battery disconnect?

Amen on the modern charger. Plug it in and forget it!

 

[TonyNoriega]

Re: Do I need a battery disconnect?

I definately recommend a battery switch for the reasons others before me have mentioned.

And when you do get it installed always turn off your motor using the key switch, rather than turning off the battery switch. I was advised many years ago that a rectifier could be ruined by doing the latter.

 

[Big Keepers]

Re: Do I need a battery disconnect?

I definately recommend a battery switch for the reasons others before me have mentioned.

And when you do get it installed always turn off your motor using the key switch, rather than turning off the battery switch. I was advised many years ago that a rectifier could be ruined by doing the latter.

If someone shuts off their motor by using the battery switch they deserve to blow the rectifier.

Simple on/off switch or the battery link I've mentioned a thousand times. It's in a few different battery threads. You need to check the motor's charging system and all that as well but a switch helps. Always trickle charge long term.