Posts: 2753
Location: Mauston, Wisconsin | suicknut- Yes you can, see the 24V charging diagram above. You can also charge them individually with a single 12V charger by switching the battery charger from one battery to the other - it just takes ~ twice as long to recharge them.
I personnaly use two (2) stand-alone Vector chargers. (2A-10A-15A selectable) -> the top one.
http://www.battery-rechargeable-charger.com/auto-vector-car-battery...
I didn't pay this price, I got them on sale at Farm & Fleet ~ 3 years ago and paid less than $100 for both....
I know there are guy's here who swear by onboard chargers - thats their perrogative. If you have lots of cash, they are OK, but I think external charger(s) are a better and more cost effective solution.
1. I can recharge any lead-acid battery - my car's - truck-boat's-motorcycle-garden tractor - portable depth finder - Xavier's electric gocart, etc.
2. I always have a spare charger! Very important if you're on a remote fishing trip and Wally World is 100 miles away.
3. Having two allows me to recharge my trolling motor batteries twice as fast (12/24V TM).
4. Yes - somone's going to say it's a pain in the butt having to get chargers from where they are stowed - I use a waterroof plastic tote, that I just leave on the dock or inside my truck cab, then you have to open the hatch. remove the battery covers - hook them up - plug them in- after charging unplug them - unhook them - replace battery covers - close hatch, stow chargers, etc
With a onboard charger you just plug it in and unplug it! But you also don't get to see/your battery(s). I get to inspect my batteries and terminals everytime I recharge them. What about loose/corroded connections, or little furry critters using your battery box as a home & chewing on cables out of boredom? The whole process takes me 5 minutes, and when I close that hatch, I know Esox Maniac is ready!
Some last words on battery safety. Be careful, especially with batteries that are recharging or have just been recharged. Every lead-acid battery evolves hydrogen & oxygen during the recharge process. A 5% hydrogen level in air is considered as explosive.This means no sparks or open flames around batteries, don't lean over a battery with a cigarette in your mouth or hands. Don't check the electrolyte level by using a cigarette lighter as a light source. Use insulated tools/wrench's (electrical tape is your friend)
A short story: Back in my military days while stationed in Germany (I was in electronics) the Divison Command Sargent Major (CSM)came over to the electronics section and asked me to help fix a problem with one of the tanks, i.e., the driver's intercom was not working, w/o intercom the tank commander can't communicate to the driver, etc. I go over to the maintenance section. The tank is sitting in the maintenance bay - main gun is facing rear. Driver's hatch is closed so I go in through the turret hatch, crawl into drivers compartment and start working on the com problem. ~ 5 minutes later one of the mechanic's climbs into the turret and says he has to do the scheduled battery maintenance. The batteries in this tank are under the turret floor - two big 24V batteries. To access them there is hinged access panel in the turret floor. The same access panel allows access to the bottom escape hatch if the gun is in the rear position. So mechanic says hey Sarge I gotta move the turret so I can service the batteries, I say go ahead. I had already opened the driver's hatch for ventilation- tanks can be pretty smelly places! I'm working, ~ 60 seconds later there is a huge explosion inside the turret. Fortunately when he traversed the turret it automatically placed a solid steel shield between me and the turret (when the turret is traversed from the travel posistion the only way out for the driver is the drivers hatch). Have you ever heard hand grenade go off? Welll imagine one ~ 5ft away inside a solid steel sphere. I am up & out of the drivers hatch in less than 5 sec. I climb up onto the turret & look down in - see the mechanic through the smoke- he's got his hands on his ears screaming - I grab both wrists and physically lift him up through the hatch - By this time guys are coming from all over with fire extinguishers etc. I drag him down onto the engine compartment and a couple of guys take over. I look down off the tank & the CSM is standing there looking at me and his mouth is moving but I cant hear him, because my ears are ringing. I tell him I can't hear him, but I'm OK. There is a 2 lb chunk of battery lead & plastic laying at the CSM's feet. The CSM was coming over to see how I was doing with the intercom problem, i.e., without driver intercom- the tank is a +50 ton piece of worthless steel. His job is to make sure the equipment and his men are all at 100% capability. It took a few minutes for my hearing to come back. The chunk of battery had been ejected through the turret hatch- hit the maintenance bay roof and landed at his feet.
The mechanic had ruptured ear drums & minor scrapes and some minor acid burns on his hands. His hands and glasses helped protect his face. What happened - he was removing the positive battery cable to clean it with an un-insulated wrench, and he shorted the battery terminal to the turret floor. The resulting spark ignited the hydrogen in the battery - unknown to me he had the tank running for ~30 minutes before I got there, to make sure the batteries were fully charged so he could check the electrolyte specific gravity (required check in the maintenance log.).
Batteries also have an lot of stored energy and can release all that energy in a very short time- what we engineers call available short circuit current (SCC)- A typical 100AH marine deep cycle no-maintenance battery can deliver ~3000A of SCC. It's fairly easy to weld steel with a battery. IT's also easy to vaporize wrenchs/pliers etc. That vapor/metal in plasma form can also do a lot of damage to your hands, eyes, face etc. Insulate any tools - for example if you have a box end /open end combination wrench, decide which end you want to use & tape up the entire rest of the wrench.
Have you ever seen someone hook up a set of jumper cables to a car/truck battery and take the loose ends and tap the clamps together to check the connection by getting a good spark? Guess what? You have just witnessed an prime example of clueless human behavior. He should not be allowed to procreate, i.e., the human gene pool doesn't need more stupidity. Think about it, what are those sparks? Are they electrons? Noooooooooo! They are piece's of molten metal - do you value your vision? Don't do this with jumper cables or any cables connected to a power source such as a battery.
Have fun!
Al |