Charging the Battery????
- Thread starter Trex
- Start date
yARIC008
Drives really slow
:/ It's called a parallel circuit. The voltage doesn't change but the amperage is doubled. If it were a series circuit the voltage would double and the amperage would remain the same. Charging one battery will charge them both. Likewise, if one battery shorts out/goes bad it will drain the other battery...
rhkcommander
Full Access Member
As long as the wiring to both batteries is good 
. If the ground is bad on either then one wont charge, likewise if the big fat pos cable between the two is corroded it wont charge the other too well
. If the ground is bad on either then one wont charge, likewise if the big fat pos cable between the two is corroded it wont charge the other too well
gatorman21218
Registered User
The "correct way" to do it im almost sure is to connect the red clip on one battery and the black clip on the other. But seeing how my charger only has about 2 feet of stretch between them I just connect both clips to one battery. Its worked that way many times. It just takes twice as long (duh!).
icanfixall
Official GMM hand model
I agree with what has been posted and I charge thru only one battery...
About you original posting... I'm not sure which battery is the main battery. They both do the same thing. they both feed the same stuff... The reason for two batteries is one large battery would be costly and way too heavy for most to remove or replace. So we run two smaller batteries to start these engines. Some will try to tell you one battery is for the glow plugs and the other is for the starter. Thats really not true.. Not even close. We need around 1800 amps to quickly start these engines. The faster we crank the engine the hotter the compressed air in the cylinders is... Thats simple science. Quickly compressed air heats up fast. Diesel requires around 940 degrees to ignite. A slow cranking engine has no chance of making the air this hot for ignition. A bump start will cause the engine to crank over plenty fast to make the needed heat. The starter draws plenty of amps as do the glow plugs. Some emebers have posted they felt their starters were cranking the engine slow and found a dirty or loose battery terminal. I actually found my drivers side positive terminal not connected once... Kinda shocking to say the least... But I had no issues with cranking speed either.... Musthave been good batteries....
About you original posting... I'm not sure which battery is the main battery. They both do the same thing. they both feed the same stuff... The reason for two batteries is one large battery would be costly and way too heavy for most to remove or replace. So we run two smaller batteries to start these engines. Some will try to tell you one battery is for the glow plugs and the other is for the starter. Thats really not true.. Not even close. We need around 1800 amps to quickly start these engines. The faster we crank the engine the hotter the compressed air in the cylinders is... Thats simple science. Quickly compressed air heats up fast. Diesel requires around 940 degrees to ignite. A slow cranking engine has no chance of making the air this hot for ignition. A bump start will cause the engine to crank over plenty fast to make the needed heat. The starter draws plenty of amps as do the glow plugs. Some emebers have posted they felt their starters were cranking the engine slow and found a dirty or loose battery terminal. I actually found my drivers side positive terminal not connected once... Kinda shocking to say the least... But I had no issues with cranking speed either.... Musthave been good batteries....
the problem with charging both batteries at once is that most chargers are peak chargers now a days. Once one battery peaks it's going to shut off the charger, whether the other is peaked or not.
no 2 batteries are going to charge the same, and charging them separately also lets you diagnose charging issues
For instance, I had one battery die in my 1600, the other was taking up the slack. If I had just charged them in parallel I probably would have never diagnosed that one battery was no good.
no 2 batteries are going to charge the same, and charging them separately also lets you diagnose charging issues
For instance, I had one battery die in my 1600, the other was taking up the slack. If I had just charged them in parallel I probably would have never diagnosed that one battery was no good.
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