Charging dual batteries

I have two batteries running in succession with a perko switch. When I want to charge them do I have to do it individually or throw the perko switch on all and just hit one? Or turn the perko off and do individually? Or perko to 1 and then charge battery #1. Thanks for your help... I know this is an easy question for someone....!!
Also another question on charging.
I don't have a charger and have found that I can charge my battery with a jumper box and then plug the jumper box in for a charge while it is charging. Is this bad in any way?
Thanks again!

I use a perko with dual batteries. I leave the perko in the off position whenever not in the water. To easy to bump a ballast switch and such. I charge each battery individually. I one wet cell for backup and use a AGM as the primary so they require different charge rates

If you are going to operate the switch manually then the best thing to do is to start off of one battery, then once the engine is running switch to ALL. I prefer starting off just one battery (verses starting on ALL) just so that you know that the battery you started off of is OK.

Once you shut the engine off you must turn the switch to 1 or 2. If you have a battery dedicated for "deep cycle" switch to that one.

Caution: NEVER move the switch to "OFF" while the enigne is running. Doing so can destroy your alternator and/or any electronics you have operating.

Note that if you forget and leave the battery on ALL once you shut the engine off then the benefit of having dual batteries is mostly lost.

The best thing to do is to get a "battery combiner" that takes care of the switching automatically. Here is a good one (but perhaps is a bit of overkill):
http://www.westmarine.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&langId=-1&catalogId=10001&classNum=12106&subdeptNum=544&st oreNum=9&productId=144540

I understand this... I am actually looking to charge the battery with a charger while parked at the house. THanks

I use one of these on my boat and also my truck. Will never be without one installed to maintain batteries.

http://www.batterystuff.com/productdisplay.html?id=358&c=115&f=ChargeTek_500_1 2V-24V_5A_battery_charger

Not familiar with the perko and charging, but for chargers I use these. Hard wire it in. Makes charging easy.http://batterytender.com/product_info.php?products_id=2

Yeah, you can charge both at the same time. Just make sure your charger can hangle both batts. My charger is good up to 125 amp hour batt, so, I cant do both at same time. But if the charger is up to it, put the switch on 'both' and connect your charger to one of the batts.

bill...how does that thing work? do you mount it inside your boat? i started to look into osmething like that a while ago, but didnt quite understand the concept and then dropped the ball. any info on it would be great. thanks.

I have it mounted on the boat and connected to both batteries. Each battery has it's own + and - connections. When I park the boat I plug it into the wall and let it sit. There is an indicator light that shows what stage it is in. This is a 3 stage charger/maintainer. Usually within a couple of hours the light turns green and it is in maintainance mode. Always have 2 fully chaged batteries. I have been using these for many years and have prolonged boat batteries the last time for 7 years before they started to break down and needed replacing. I feel for a boat battery that is pretty good. Hope this helps.

Thanks Bill.... I think I will pick one of those up...