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Can you Jump start a car with a dead alternator?


David1006
07-17-2016, 09:15 PM
Hello Everyone,

I have a 2005 Mazda 6 my alternator died yesterday and i need a replacement. Since the alternator is dead it didn't charge the battery so it dead overnight. now my car wont start here when I'm have a bit of confusion i need to get my car running so i can drive it to my friends garage to replace the alternator. will jump starting a car keep it running long enough to get it to the garage or will i need to fully recharge the battery to get it running? I'm nervous about jump starting the car because the alternative won't be recharging the battery so my car might die before i get there

brcidd
07-17-2016, 10:11 PM
Put the jumper cables on the car- have the donor car running and walk away for 30 minutes-- this will charge your battery and you can start your car and drive it up 30 miles--- charge it for 20 minutes will get you 20 miles-- yes you will be running off your battery, but you can drive it to be repaired. I do this all the time-- sometimes I just sit a battery inside the car- run jumpers out to the dead battery and drive the car to where it needs to be...

David1006
07-17-2016, 10:20 PM
Put the jumper cables on the car- have the donor car running and walk away for 30 minutes-- this will charge your battery and you can start your car and drive it up 30 miles--- charge it for 20 minutes will get you 20 miles-- yes you will be running off your battery, but you can drive it to be repaired. I do this all the time-- sometimes I just sit a battery inside the car- run jumpers out to the dead battery and drive the car to where it needs to be...

Thanks for the ideal ive been looking online for car starter or battery charger will a car battery charger work as well take off the car battery charge it overnight and put it back in? or have a portable car jumper?
https://www.amazon.com/NOCO-G750-UltraSafe-Battery-Charger/dp/B004LX3AS6/ref=sr_1_3?s=automotive&ie=UTF8&qid=1468798646&sr=1-3&keywords=car+battery+chargers
https://www.amazon.com/NOCO-G750-UltraSafe-Battery-Charger/dp/B004LX3AS6/ref=sr_1_3?s=automotive&ie=UTF8&qid=1468798646&sr=1-3&keywords=car+battery+chargers

shorod
07-17-2016, 10:25 PM
The better approach, simply because it doesn't require idling a car for long periods of time, would be a dedicated battery charger. But for an overnight charge of a completely dead battery, you would want something like 2 amps or higher. That basic 0.75A unit in the base links you provided would be more like a battery maintainer, not a charger per se.

The portable jump starters are typically better suited for a car with a working alternator but dead battery because some accessory was left on or the battery is weak. The new lithium-ion starters are good for small engines, but so many are listed with WAY higher capacity than the batteries actually provide so it's difficult to know what you're really getting based off the "specifications." For example, a pack may be listed as having a 16,800 mAh capacity, but what they've done to come up with that number is added the total capacity of the three 5,600 mAh cells up. However, since the cells are wired in series, the effective capacity is still only 5,600 mAh. If the cells can handle a 35C continuous discharge rate, then they list the pack as having a 200A current rating. What they fail to mention is the 5,600 mAh rating of the cells is the capacity at a much lower discharge rate for the inexpensive units with bargain cells. The higher priced, name brand units likely have less inflated specifications, but they also will likely be physically larger.

-Rod

David1006
07-17-2016, 10:55 PM
The better approach, simply because it doesn't require idling a car for long periods of time, would be a dedicated battery charger. But for an overnight charge of a completely dead battery, you would want something like 2 amps or higher. That basic 0.75A unit in the base links you provided would be more like a battery maintainer, not a charger per se.

The portable jump starters are typically better suited for a car with a working alternator but dead battery because some accessory was left on or the battery is weak. The new lithium-ion starters are good for small engines, but so many are listed with WAY higher capacity than the batteries actually provide so it's difficult to know what you're really getting based off the "specifications." For example, a pack may be listed as having a 16,800 mAh capacity, but what they've done to come up with that number is added the total capacity of the three 5,600 mAh cells up. However, since the cells are wired in series, the effective capacity is still only 5,600 mAh. If the cells can handle a 35C continuous discharge rate, then they list the pack as having a 200A current rating. What they fail to mention is the 5,600 mAh rating of the cells is the capacity at a much lower discharge rate for the inexpensive units with bargain cells. The higher priced, name brand units likely have less inflated specifications, but they also will likely be physically larger.

-Rod
Seem like the battery charger would do the smarter buy im thinking about buying the NOCO Genius G3500 3.5amp should work the car as a 2.3L 4 cylinder engine

shorod
07-18-2016, 07:28 AM
That would work fine for charging the battery overnight. It won't be a quick charger though, meaning if you go out to your car in the morning to leave for work and find a dead battery, you won't be able to hook this up and start the car after 20 minutes of charging.

-Rod

David1006
07-18-2016, 10:42 AM
that's fine by me i don't plan on using it till i fix it just need it to be charge so i can take it to be repaired thanks a lot for your help guys.

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