Using a float charger/tender

eavega

Lieutenant
Joined
Apr 29, 2008
Messages
1,377
Hey folks

I've had some battles with my HOA this year regarding the storage of my boat in the back yard, and for the time being am keeping my boat in the garage. When I kept it outside, I would remove the battery after every outing and store said battery in the garage. I would then put the battery on a tender to make sure it was fully charged before every trip. Now that the boat is in the garage, I was wondering if I could just leave the battery fully connected in the boat and just put the float charger on it there (without disconnecting the outboard electricals from the battery). My concern is harming some electrical component on the motor (1976 70 HP Johnson) such as the rectifier. I suspect not, as the float charger is not working at an aperage higher than what the motor would normally see, but I just wanted to be sure before I am surprised with a non-working tach or charging system.

Along the same lines, is there any danger in putting the higher amperage automatic charger (10A fast-charge or 2A slow charge) on the battery while it is still connected to the outboard? Same concern, particularly with the 10A setting, since I believe that is higher amperage than the outboards charging system.

Thanks in advance for information.

Rgds
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
Re: Using a float charger/tender

You do not need to remove or disconnect the battery to charge it. YOu do not have to worry about using a float charger or a smart charger (2 amp, 6 amp, 10 amp, or 20 amp) since the final stage of charging is the "float mode". The charger can be left on 24x7 without damage to any electrics. Batteris "accept what they need" from the charger up to the limit of the charger output. It is not as though the charger is "forcing" its full output into the battery at all times.
 

5150abf

Vice Admiral
Joined
Aug 12, 2007
Messages
5,808
Re: Using a float charger/tender

If the boat is in the garage the key is off so the engine and msot other things are sperated form the battery anyhow so you can't possibly damage them.

I have an onboard charger and leave it hooked up for long periods with no damage to batteries or anything else, I will pull and fully charge my batteries at the end of the season but that is the only time they come out of the boat.
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Using a float charger/tender

My boat's rigged with chargers built in. 20 amp 2 bank charger for the trolling motor batteries, and a 1 1/2 amp maintenance charger for the starting battery. I lost a battery a couple of winters ago with a cheap harbor freight float charger. Use quality chargers. When I back it into the garage, I just plug in one AC cord and open a cover to allow a little cooling for the bank chargers.

No need to take them out of the boat. Make sure everything is off just so the chargers don't have to supply power to run dash lights or something. With quality chargers, you don't have to worry about cold either. Should be good down to 60 below or so.

hope it helps
John
 

eavega

Lieutenant
Joined
Apr 29, 2008
Messages
1,377
Re: Using a float charger/tender

Thanks very much for the info, guys. I was figuring all was well with leaving the float charger on, but I wanted to hear from more experienced owners (and engineers) that it was okay.

Rgds
 
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