Battery Chargers

I recently acquired a ProXOne Battery Charger. I will be using it to recharge auto batteries when they are out of car.

Here’s my question.
For Negative ground batteries, most on-line sites say to connect Charger-red to Battery positive and Charger-black to “6-gauge (AWG) insulated battery cable” which then is attached to Battery negative. Interestingly enough. the ProXOne instructions make no mention of this procedure and basically says to connect charger black cable to Negative terminal.

I have no problem using a 6 gauge battery cable, if I know where to find one. I could buy another set of Jumper cables, I guess, but already have 4 gauge set of jumpers. So:
1-Do I need to use any cable between battery and charger, and 2-if so, will 4 gauge work?



Hook the charger up to the positive and negative terminals of the battery

That’s all there is to it

I think they are overly worried about a spark and a hydrogen explosion. Just turn on the charger after you hook it up.

@wentwest has good advise that I’ve followed since the beginning. Hook up straight to the battery, then plug in the charger. No sparks that way.

I suppose there could be some add’l safety if you use a cable between the battery and the charger. Moves the spark away from the battery. Batteries can give off H2 gas which is explosive, 2H2 + O2 = 2H20 and lots of heat, ever see a Saturn rocket lift off for outer space? That’s the chemical reaction that powers it. But batteries they usually only out-gas H2 on rapid charging and discharging cycles, not when the battery has been dead and unused and uncharged for several hours. If someone has been trying to start, then restart their car several times, and they ask you for a jump, that is when to be extra careful about sparks around batteries. But better safe than sorry maybe. Auto parts stores sell replacement battery cables which have the connector that fits the battery post on one end, and plain wire on the other, I bought some recently, less than $10 as I recall.

Thanks for quick responses everyone. I went ahead and followed all the advice offered here, with no explosions and battery charged fine.
Re GeorgeSanJose’s suggestion of replacement battery cables, I’ve only been able to find 4-gauge, which, I suppose, is better that the proverbial sharp stick.

Connect the battery with the charger off–make sure you have a good connection on each post. Turn the charger on. When charging is finished, turn off or unplug the charger before disconnecting the charger from the battery. Only charge a battery in a well-ventilated area–they do give off hydrogen gas and hydrogen sulfide–the first is explosive and the second is toxic and explosive. (and stinky too) If you hear a battery boiling furiously during charging (some noise is normal), turn off the charger and let things cool down before approaching the battery.

When working with a lead-acid battery, it’s good to wear eye protection and always avert your face from the battery when connecting/disconnecting.

PLEASE take oblivion’s comments seriously.
I had a battery blow up on me when I was 19 because I didn’t follow the steps given in his advice.
One’s eyesight is too valuable to loose to a few sloppy steps.

@Zalophus - just so you know, 4 gauge is thicker than 6 gauge, so any time 6 gauge is suggested, 4 gauge is even better (for the same length cable).

I will be using it to recharge auto batteries when they are out of car.

Since you are charging batteries out of the car, the whole “connect to the cable which is connected to the negative terminal” jazz is completely irrelevant since there are no cables connected. Just follow the advice from @BustedKnuckles and @oblivion regarding the order to use when connecting and disconnecting.