I recently had a disagreement with a neighbor who had asked me to give his dead battery a boost. Being the kind and sympathetic neighbor that I am, I complied, albeit, with reservations. Everyone uses their own boosting technique--which typically involves keeping the boosting vehicle (good battery) running, sometimes even goosing the accelerator to supposedly provide power more quickly to the uncharged battery. But I insisted on using my own technique--which involves keeping the ignition and all other components in the boosting vehicle off. After providing 15-20 minutes of charge time to his vehicle, some components began to work, but there still wasn't enough power to start the vehicle. I told my neighbor that I had an appointment, and he insisted that I try again, but suggested I start my vehicle and "give it some juice".

I refused on the basis that doing so might jeapordize other electrical components, namely, my alternator. Doesn't the alternator compensate when more power is drawn from the battery, which could potentially cause it to over-compensate, perhaps damaging or destroying it? How much more power, if any, results from having the booster vehicle running? It seems like an unnecessary and unbeneficial risk.

Thank you for any input.

 

IVe helped boost some friends car with mine runing and really it shoun't hurt anything it's only for a brief second...from the time the cables are hooked up to the time you start yours to when he start his and as long as the battery is fused which it is there should be no problems with electronics frying.

 

just turn it on and make sure you are on the gas a little when he cranks it... i've done this plenty of times.

 

I have also done this many times, and never had a problem.

 

Same here...Never had a problem....

 

Your worry is very valid. When you hook up his, the dead battery, to yours, you are doing so in parallel. If you car is running, or you start your car after the initial hookup, your alternator would not know the difference between which battery belongs to which vehicle. It only see one storage device, both your battery and his combined, and since his battery is weak it'll attempt to recharge it.

I don't know for fact whether the OEM alternator is capeable of recharging a badly discharged battery with no ill effect or not. But my thinking is that if it has to work harder to recharge then something has to give.

The safest method of boosting another car that I've read about is to connect both batteries with both cars off. Wait for couple minutes for the weak battery to get some charge, then start the dead car. Of course it's better to have your car running to charge the other battery faster but it'll probably put more strain on your alternator.

 

I have boosted vehicles with my truck(95 nissan 4x4) dozens of times, and I always leave it running. I have never had any alternator problems. I would recommend getting some heavy gauge(00) cables. I have had cheap 2 & 4 gauge cables melt.

 

I think the guy should buy a handheld battery booster or get the car fixed.

 

deezo, how heartless you are

 

Few things are wrong with this picture. 1. His car has other problems because he couldn't even started with your good battery. OR 2. You have a weak *** battery that's about to die. OR 3. You or your neighbor hooked up the damn jumper cables up wrong.

 

Ok, look at it this way. How would the alternator be over extending itself? if the alternator has to pump out more juice, the battery gives it, and vice/versa. Yes, the overall amperage is going to go up, but it is not ALL going to come from the alternator. If all the juice from a car came from the alternator then our cars would still have pull cords and cranks. Like any type of electronics, extended peroids of hard use is going to heat it up, until it burns out. As long as you do not overheat(extended use) your electronics and everything would be fine. I believe that the car running is the most efficient use of resources. Now If it did not start after 2-3 minutes I would quit for a bit so that I would not overheat(not over compensate) the alternator and other electronics. IMHO this is just my $1.10

 

Well, I am highly into electronics and what not. I can tell you that the alternator will not fry-out or get hurt. NOW if you were to keep it connected and keep your car running to his connected dead battery for like hours, then yeah the alternator will begin to over-do itself. But for only 5mins? not even 5mins, I mean with your car started, MOST dead battery can be started. I mean if the battery is COMPLETELY drained, then 5mins will be more than sufficient.

But no, there is NO WAY you will mess up your alternator in 5mins.

SideNote: I mean think of it this way, there is a voltage regulator in your car, when the battery is completely charged, the voltage regulator tells the alternator to stop working so hard. Well, your car is full charged, and the alternator can spare working hard for 5mins. I mean lets say you turn the AC, 500Watt stereo, Heated seats, rear defog.......Your alternator will be working hard then. Your are not killing it then.

Dixit