Dual Batteries
 

Ok I walk out this morning and I left the sunroof open. So I turn the trucks key to the one position. Roll the sunroof up and leave the key on. 5 hrs later I get in and its dead. I get in started and decide to charge the batteries I wasnt sure of if it was ok to just hook some battery chargers up with the batteries still hooked to the Truck so I undo the batteries from the terminal and start the charging.
The question is can I hook battery maintainers to both batteries and charge them while the batteries are hooked to the truck

One battery tender is ok but not 2 with the batts hooked to the truck or together. You don't want to put more than nominal 12 volts to the system or it will go into melt down. You can hook up one batt charger/starter to them with them hooked to the truck to get it started.

So will one battery Maintainer charge both batteries

Eventually yeah.. Just get the truck started and drive it to charge the batteries. Can't you jump it with another vehicle or something?

Oh I got it started ran fine. I was just wondering for thise cold times that she may not be ran for a day or two

Yeah, just hook a tender up to one battery and leave them in the truck.

The important question to this is the battery setup: are they simply connected in parrallel, or do you have relay between them? Or a real diode insulator setup?

Do you use the same batteries: same brand, age and capacity?

Depending on your battery setup you may need different chargers.

Details are important here!

Depends on the battery tender. You will just have to read the destruction manual.

They are the same batteries and I am assuming that they are just the way Ford put them in the truck if that helps

For you to charge both batteries at the same time at the same rate. Hoop up the pos. to one battery and the neg. to the other battery. Now both will charge at the same rate.

You can do that but it's not necessary, your answer is yes the way ford put them in you can hook tender to one battery and both will charge with all battery cables hooked up. :c:

By hooking up to one battery. The first will take the charge and only after the hooked up battery is fully charged will the charging start on the later. This is especially true with a battery tender. Because of the low amps being put out. So in this case if you have the tender on one battery and not what the full cycle time to have it fully charged and need the truck. You will have to disconnect the tender and not have charged the second battery. This makes the first battery stronger and the weeker batter will drag down the first battery. Well you know what I mean.

I understand, but as far as maintaining a charge it dosn't really matter, now if the batteries are low and you are charging them you have a good point :c: