Trickle charging dual batteries

[Bony1]

I have a dual battery set up and controlled by a 4 position rotary perko switch with the following settings "off, bat1, both, bat 2"
The boat has been sitting in my garage for about 6 months and I want to use a trickle charge battery tender to bring the batteries up to full charge.
Do I need to disconnect the batteries and charge them individually or can I position the switch to "both" and charge them simultaneously? If I do charge them with the switch in "both" do I run the risk of damaging my electronics?
Thanks

 

[Silvertip]

The charger should have been on for the last six months. If it is a trickle charger (less than two amps) it will take a hole to charge both. You don't need to remove the batteries. After all, the engine charges then the boat . You can set the switch to BOTH.

 

[Bony1]

The charger should have been on for the last six months. If it is a trickle charger (less than two amps) it will take a hole to charge both. You don't need to remove the batteries. After all, the engine charges then the boat . You can set the switch to BOTH.

Thanks, I realize I should have been tendind the past six months, but wasn't sure how to do it. You said "it will take a hole..." Did you mean "whole" as is whole day or week to charge the batteries?

 

[garbageguy]

When the boat is running, does the switch need to be on "both" to be charging both batteries?

The OP's original question is the same as I was going to ask. I did not start a separate thread as not to duplicate. My apologies if my post is considered a hijack and if so, I will not do that again.

 

[alldodge]

Thanks, I realize I should have been tendind the past six months, but wasn't sure how to do it. You said "it will take a hole..." Did you mean "whole" as is whole day or week to charge the batteries?

If the batteries do need charging them it would be my opinion that the trickle charger is not going to do it. It would take a "whole lot" of time and 2amps split across two batteries, is about like trying to fill a bath tub that has a slow leak with an eye dropper.

Put the selector on both and with a single good charger or the engine running it will charge both batteries

 

[alldodge]

When the boat is running, does the switch need to be on "both" to be charging both batteries?

The OP's original question is the same as I was going to ask. I did not start a separate thread as not to duplicate. My apologies if my post is considered a hijack and if so, I will not do that again.

Yes, it does.

Also if the engine is started on one battery, do not switch the switch to both, it can damage the alternator.

 

[garbageguy]

if the engine is started on one battery, do not switch the switch to both, it can damage the alternator.

Do you mean don't switch the switch while the engine is running? Thank you.

 

[alldodge]

Do you mean don't switch the switch while the engine is running? Thank you.

Correct, only way you can safely switch the switch while the engine is running is IF you have a switch which contains a micro switch in side it. The micro switch turns the ALT off (field winging disconnect) when switching is in progress and then turns it back on. There are several out there but have to look for them. Google marine battery switch with alternator field disconnect

 

[Silvertip]

Switching is not an issue with an outboard as long as it's a make before break type.

 

[bruceb58]

Yes, it does.

Also if the engine is started on one battery, do not switch the switch to both, it can damage the alternator.

99.9% of switches are fine to switch from one battery to both. Like Silvertip said, they are make before break. I haven't seen one that isn't that way ever.

 

[alldodge]

99.9% of switches are fine to switch from one battery to both. Like Silvertip said, they are make before break. I haven't seen one that isn't that way ever.

Need to look a little closer

 

[bruceb58]

Need to look a little closer

I had one on my 1988 boat that I cracked tightening the connections. I decided to take it apart. It was a make before break as well and that was from 27 years ago.

Go to the BlueSea site. You will see that the alternator field disconnect is only activated when switching to the off position.

 

[bruceb58]

Here is an example of a Perko switch with make-before-break.

Make-Before-break feature allows switching between 1-all-2 positions with engine running.

It is also mentioned that an AFD is available in case you turn the switch to OFF. personally, I never bother with an AFD. Just make sure you don't turn to off with the engine running.

 

[alldodge]

I had one on my 1988 boat that I cracked tightening the connections. I decided to take it apart. It was a make before break as well and that was from 27 years ago.

I'm sure there is no one which knows more about this marine electrical components then you Bruce. As you say Bruce there has been no manufacture which has ever made a non-make or brake switch in the past 27 years, and there are no switch's currently being made which even have the remote possibility of such

 

[bruceb58]

Glad you agree!

I am sure whatever you have on your boat is the same way!

The only thing that is probably more of a concern is the switching under load which may have a greater chance of arcing a contact