Recharging batteries safely/quickly

[Bassin101]

I have read that you should charge your batteries in a well ventilated area.  Does anyone recharge in their garage with the door closed?  I currently take the batteries from the boat to the patio to do it.

Also, is there a way to hook two batteries together so I can charge them at once? ???

[ernel]

My father-in-law is a manager at a local Napa store, and all of there charging is done indoors. If you leave a small crack in the bootom of the door with a small fan blowing toward the boat, you should be fine.

You can hook both batteries together red to red and black to black, and then hook the red charger lead to one battery and the black to the other, but it will not speed up the charging process. It will take the same amount of energy to charge both batteries. Your charger will still be putting out the same amount of amperage.  10amps into two batteries will equal 5amps per battery.

If you want to charge both batteries at the same time efficently, you will need to buy another charger. Either buy a multi-bank charger, or buy another single bank charger and use both of them at the same time. With the cost of multi-banks, I just bought another single bank charger for a little over half the cast of a multi-bank.

[Bassin101]

Thanks ernel, if I hook them together like you said, will it make any difference if one battery is dual purpose and one is trolling?

[Bassin101]

Does anyone use 3 stage chargers?  Currently I use an old 2/6 amp charger.  Do the 3 stage charge quicker, more efficiently,  :-/prolong battery life etc?

[ernel]

I would not mix the two batteries. There is a slight difference in the make up of the two batteries.

Also on my first post I should have siad that both batteries should be the same size (amperage), age, type and drawn down to the same power level. If not one batttery will charge before the other and could lead to boil off of the dielectric in that battery.

It will take 18-20 hours to fully charge both batteries if you do decide to charge them together. A 6 amp charger split will be just like a trickle charge.

If you are looking at a multi-bank, I would look at one of these:

http://www.basspro.com/servlet/catalog.TextId?hvarTextId=45195&hvarDept=200&hvarEvent=&hvarClassCode=3&hvarSubCode=4&hvarTarget=browse

If you have a 24 volt t/m set-up you can still use the old charger for the cranking battery. It should not be drawn down as far as the other two. This last little bit is just my opinion. If I were to buy a multi-bank, I would look hard at one of these

[ernel]

Forgot about a the 3 stage question. A three stage will charge faster, if it is set to the highest output. The only drawback to high output chargers is when something goes wrong. (Ie. the auto off feature goes out.) This can cook a battery. I only charge on the high output whenever I can keep an eye on the charging process. It only takes 1-3 hours to charge my bateries when using the 12 amp funtion on my two chargers.

[abelfisher]

I charge my battery in the garage all the time with the garage door down.  It is a two car garage.  Unless your garage is exremely air tight whcih most are not, I don;t think you should have a problem.  Obviously, never put your battery on the concrete floor as this will zap the power quickly.

[Bassin101]

Ernel, when my batteries are in the fair range, I charge for 12 hours at 6amp and a little longer at 2 amp.  Do you think if I went to a 12 amp I could cut my time to 3-4 hrs per battery?

[ernel]

That sounds about right.