Is it ok to charge the battery without removing the battery cables? It's a pain to reset my stereo/bluetooth setup. Thanks.

 

Not to be a smart azz, but the alternator charges the battery without removing the cables... Think about it...

 

Shouldn't hurt anything. I have charged the batteries on lots of stuff and never unhook the cables. I haven't hurt anything yet that I know of. I never charge faster than 10 amps.

 

If you have a charger that would damage your truck, it would also damage the battery. No battery charger should ever allow the system voltage to exceed 14.7v which should be about where the regulator on the alternator normally tries to keep voltage.

Most smart chargers are really good about charging in phases and will never cross that 14.7v line. If you are using a "dumb" charger with a few selected amperages, then you really need to keep an eye on it either way. If the voltage exceeds 14.6 when your charges is connected, you need to drop the charging rate.

One thing to keep in mind, is that batteries will emit hydrogen gas while they are charging, and some batteries under some conditions may leak acid. I work for a agricultural equipment dealership and not too long ago we had an "unofficial recall" because a certain series on tractor had a voltage regulator the allowed to voltage on the battery go a couple tenths of a volt higher then other series tractors. All of these tractors had to have the batteries swapped to a different type of battery that would accept the slightly higher voltage, otherwise the batteries would leak acid while the tractor was being used. The hydrogen gas and acid caused corrosion issues under the hood of the tractors affected.

Ultimately it's not a huge deal. But depending how how paranoid you are, or if you have a million dollar show truck, it may make a difference. I take the care of my trucks pretty seriously and still have no issues with charging the battery in the truck.

 

"Dumb" chargers, old school type with a transformer, of the sort for consumer use are sized perfectly for the typical automotive starting battery. 50 to 70 Ah.

But, the end point charging voltage is temperature dependent. Current starts out high and voltage low and current tapers down to nil when fully charged in this type of charger. They aren't regulated, but in cold weather the internal resistance of the battery increases quite a bit. It would be tough to hurt anything in truly cold weather because the end point voltage is limited. In warm weather though the end point voltage will spike above 17 volts and boil the battery dry if it is not disconnected.

What am getting at is I routinely fully charge with the old school charger now and then and hold at 16.25 volts for a few hours known as an equalization charge, in the Ranger. The "Dumb" chargers are great for this.

One thing I try to do, is disconnect battery tenders - designed for indefinite connection - during thunderstorms. Nearby lightning strikes can induce power spikes in home wiring and strange things like that, so I don't want to zap anything.

 

Thanks all. Everything I wanted to know and then some.

 

Wasn't trying to devalue a basic transformer & diode charger. Just mentioning that they should be monitored. If I'm ever doing an equalization charge, I monitor the temperature and voltage of the battery and keep en eye on the fill level of each cell.

This type of charging should really only be done on batteries that rarely see a full charge and are suspected to be suffering from sulfation, as it is known that equalization charging shortens the life of a battery.

I wont do this type of charging in vehicle because of the off gassing and high risk of acid spill. But hey, everyone here can decide what level of risk they want to accept.

 

I'd argue it's done to prevent sulfation in the first place. It's part of the standard charge tables. It's done to maximize battery life.

Once a battery is "sulfated" - charging it is like trying to wash your hands wearing gloves. Equalizing voltages between cells and mixes electrolyte etc. Moderate outgassing is a good thing when charging.

http://www.batteryfaq.org has charge tables if interested in this. See for yourself. But to the original question it's (probably) not going to hurt anything in the truck itself. I guess I'd have to say "you're on your own". Maybe different models have different issues, too. I took a calculated risk it wouldn't hurt anything, but as they say YMMV. Everyone sez disconnect battery when doing this, for that reason. Don't turn the key on or any accessories or anything like that.

On one of the lawnmower forums a guy had a tender type charger on a battery in a spare bedroom (bad idea) and the "smart" charger forgot to go to sleep and the battery boiled itself to death. Battery Tenders themselves are good in that modern vehicles have all these parasitic loads constantly sucking juice, they counteract that slow drain and keep everything from sulfating up. That's what kills batteries. Another charger I have goes through the standard charge cycle by the numbers, right up to around 16, then down to float it's temperature compensated I suppose. Have to measure it yourself though, the display just says "12" no matter what. Too many customers probably about had a coronary ha ha.

 

Quote from batteryfaq.com

"Equalizing can reverse the build-up of the chemical effects like electrolyte stratification where acid concentration is greater at the bottom of the battery. It also helps remove sulfate crystals that might have built up on the surface or in the pores of the plates."

Thanks for the link. These tables are a bit like the one I made for myself that would spit out open circuit voltage readings for different state of charges once I entered the battery temperature. I didn't have anything for AGM batteries though, so this is a big help.

I agree 100% that "smart" chargers need to be monitored just like any other charger. Most are made on the cheap and are not guaranteed to always switch modes as they should. The two things that will kill a battery the fastest are overdischarge and overcharging.

After reading a bit more on batteryfaq I'm bit more comfortable with equalization charging. I only ever used that method on batteries I would pick up from the recycling queue that I thought I could save, never on batteries that I already had put into service.

Reps to you for sharing the link . I'm sure the OP got more than he bargained for