I unplug it then get the boat ready for the days fishing trip.

Seems to me that you run more of a risk of having something spark by the unit going on and off regularly during the time the boat sits vs. just leaving it charging and then going into trickle charge mode for the rest of the time, but that is just a guess.

I have a timer for sale. Shoot me a PM.

That's a good one. I didn't spend enough time searching. I've noticed Amazon search is less robust than it used to be - they shove a lot of carp at you. The drawback of a one-time countdown is if the owner happens to not visit the boat for a month in the winter. But, great idea for a lakehouse you visit often. I unplug mine, even though the technology says you don't have to, but that's "you don't have to if everything works as it should." I've known two people who had major fires centered on their bass boat in the garage. The boat and much more were a total loss. I saw horrible photos, and both clearly centered on the rear of the boat where a charger was plugged in.

Mine is automatic. I use a 24 hour timer at my bussines to run my pump on tankless hot water heater. Bout 20 bucks at home depot. Plug into socket then it has 2 outlets on it. Should work fine.

This one

I never had a problem with the timer, in fact it is still in use for some lights. You look at the amp rating of the timer and don't buy a kitchen timer. I did have problems with on board chargers just going bad and not charging the batteries and one over charged and killed the batteries. I got tired of buying expensive on board chargers and went the old fashioned way and use clamp on chargers.

When I did use the timer, I had it set to come on for 6 hours every night during the week.

In the failure cases I know of that resulted in fire, it appeared to be the charger itself that was the issue, not the number of amps that went to a battery, so fuses in the charging leads don't protect from that type failure.

Why do you heat your hot water if it's already hot? I bet you have a tankless water heater, right?

P.S.: I have a bottle with the racehorse on top, but I think it has a leak as the level goes down. I need a replacement, I think. Got extra?

If you have a modern charger and put it on a timer to go on and off once a day as some have mentioned your asking for more trouble than just leaving it plugged in all the time.

When you turn these modern chargers on (plug in) they run thru the FULL charge program, which would be running the charge up to 14.2 volts over xx amount of time etc, then after that full program is ran up and back down, they go into a float or maintain type of low charge rate pattern which uses very little voltage.

Go feel your charger 10 minutes after plugging it in and youll see you clearly dont want that going on every day with a timer.

Many that I have seen do a voltage check when powered up. This is to see if the battery needs to be charged. If it does not, it quickly bypasses steps of the charge profile and goes to float.
Yes, if you feel of a charger 10 minutes after power up when connected to batteries that NEED a charge, you'll feel it warmed up. If the batteries don't, most modern chargers go to float and stand-down from the forced charge step. This is often indicated by the LED status (such as a solid green light as opposed to red).

I'll repeat that I've seen two garages burned to a total loss with boats & battery chargers that were connected 24/7. I've never seen an unplugged charger cause a boat and garage to burn.

Just finished building my own timer switch. Intermatic 101 mechanical clock with on or off movable/removable paddle keys. Cut a good 15 ft. extension cord and wired the Intermatic between the plugs. Now I can use only the off paddle set to trip for however long I want to leave it on. Mechanical clock eliminates electrical relays. Still not 100% safe since the charger must be on for an extended period, but I will sleep better knowing my Ranger isn't always plugged in.

That was a good approach. The different on/off paddles makes it possible. The ones with 24 one-hour on/off sliders won't do what your simple modification will.

Ive got a dual pro charger and it absolutely does not go straight to green it will show 2- 3 lights lit if Im charged already and run for at least a few hours thru the program before it goes all green which I think is 5 lit then green... My spare dual pro does the same.

I don't see any justification to go the full cycle. They can sense the voltage. NOCO does different. I had not run my Dual Pro in a long time. Those things are heavy! The 4 bank pro series is 29.5 pounds per their specs. I pulled it out. If the charger gets through phase 1 of the profile quickly, then the amps drawn will drop off quickly, and consequently heat/power drops substantially. If it runs a fixed amount of time regardless of battery condition, the battery will get heated up unnecessarily from excess current.