Battery boost

[Ralph Mowery]

Small rockets attached to military planes to allow them to take off on short runways. Jet assited take off.

[clare]

As I was saying. Jato booster pack on Rancharger to beat the 'Vette!! (Not really - but - - -)

[clare]

I missed putting in the ? - it was arhetorical question

[Eagle]

Farm Truck and Azn put one of those JATO rockets on a 3 wheeled bike on "Street Outlaws". Farm Truck took off like a cat with a rocket up it's butt... 8-o

[Eagle]

[e-mail] pretended :

Oh...got it. lol

[Mark Lloyd]

[snip]

The last time I called AAA (it was because of a dead battery), the driver didn't use jumper cables, but had a portable battery pack. It started and I drove to the shop. Battery replacement was free (battery was less than 2 years old).

BTW, when I shifted the car info gear (after AAA started it), it almost died. The lights got really dim.

[bob haller]

lacement was free (battery

my vans battery died, i got it started with my 200 amp boost battery charger.

i used the electric door lock and the engine nearly died. the garages battery tester reported bad cell. the battery was only 2 years old and replaced for free under warranty

[Stormin Mormon]

Sounds like you had bad alternator?

One battery jumper pack I bought, had a caution not to leave it under the hood and use it as a starting battery. I guess someone probably tried that. I find it easier to replace the battery when needed, not try to rig up some thing.

[Mark Lloyd]

or it was nearly overloaded from trying to charge a bad battery, so the transmission caused enough voltage drop to interfere with ignition.

Maybe it won't be too much longer before we have lithium batteries that completely replace lead-acid.

[Don Y]

And cars spontaneously bursting into flames?! :>

[notbob]

Once the battery starts the car, the charging system is supposed to take the battery totally out of the circuit, providing charge to the battery only as needed and capable of providing (do they still call it a voltage regulator?), but not at the expense of the running engine.

It's why checking your charging system is as simple as disconnecting the battery from the circuit after starting the engine. If the electrical/charging system is working properly, no battery is necessary, and it can be completely removed from a running vehicle.

Not sure if this applies to newest vehicles, those with onboard computers and event data recorders (ERDs) and other digital nonsense.

Give it a try. Start the engine in yer vehicle. Disconnect the battery (remove neg cable) and the engine should remain running.

nb

[Don Y]

I think that only *nominally* works. I'm not sure alternators are sized large enough to handle worst case loads -- even on cars with *just* "factory equipment" -- headlamps, foglamps, sat heaters, sound system, navigation, windshield defrosters (front & rear), etc.

I suspect there is some duty cycle calculations that goes into how these loads are reflected in the alternator's output capacity. And, how variations in the field affect output.

[DerbyDad03]

It's not just the digital stuff.

Regard "Follow these precautions when using the seat heaters:

Use the HI setting only to heat the seats quickly, because it draws large amounts of current from the battery.

If the engine is left idling for an extended period, do not use the seat heaters, even on the LO setting. It can weaken the battery, causing hard starting."

In other words, there are some systems that still draw current from the battery, even with the engine running.

No thank you.

[Eagle]

You mean like the cars from Tesla?

[Stormin Mormon]

I've heard that causes a major voltage spike. Damages electronics. Not a good test now days.

[Eagle]

Oren explained on 1/3/2016 :

Welcome to century 21.

[clare]

Not true on all vehicles, and a dangerous way to test on others. The battery on MOST vehicles today needs to be in place for the vehicle to run and the charging system to function.

Don't try it. Some vehicle computers can be damaged by removing the battery connection while the alternator is charging.. The best way to test if an alternator is running is with a voltmater or other charging voltage indicator (there are boxes with several LEDs that light up telling you either the voltage or the condition of the charging system) The proper tool to do the test is CHEAP and readily available, and something every automotive DIYer should have at his disposal.

[clare]

Most vehicles have a large enough alternator to handle all normal loads plus charge the battery when running at road speed. Not at idle. HOWEVER. Note that some vehicles will not run without the battery even if the alternator is working properly, and some vehicled will destroy the computer if run without the battery.

Please, only test your alternator function with a proper voltmeter.

[Ralph Mowery]

With all the electronics on the newer cars I would not chance unhooking the battery.

Even the $ 6 or free multimeter form Harbor Freight will do the check the charging system. Take a volt reading before starting the car and after. If the voltage does not go up, look into the charging system. The meter does not even have to be accurate, just compair it to a known good car if in doubt.

[Stormin Mormon]

My quick and easy test for alternator voltage is to turn on the windshield wipers. The wipe rate gives me a quick idea if the voltage is low.

A VOM (volt ohm miliameter) can also be useful. If one knows what to do, and where to check. I've done alternator tests with one.