Is this a good way to charger portable jumper?

[79sunrunner]

Bought a Peak 750 amp jumper. The instructions are a bit scewed on proper charging instructions, and I feel it would be better if I used my battery maintainer I use on my classic cars.

The handbook does not specify if there is a built in advanced maintainer, or if its just a trickle charger (the one that sulfates and over charges) So I used the 12v socket for charging.

The digital power meter seems extremely inaccurate at predicting full charge, so I am keeping an eye on the digital meter and green light on the charger to see the time difference between when both register.

If anyone has suggestions, warnings please comply. I am just as picky with battery maintanance as I am with engine oil.

p.s. I learned 750 amp isnt enough to turn over a Jaguar v12 engine

 

[Rand]

thats because its "peak amp" Its probably more like 350amp when rated as a regular car battery.. and of course thats not CCA.

You probably need at least an "1100 amp" model for that car.


or this one
http://www.sears.com/diehard-high-performance-portable-power-2200-with-jump/p-02871990000P

 

[901Memphis]

As long as you set the charger for correct battery type your fine, I have done the same thing in the past. You must have an AGM setting on your charger as a regular flooded only 12v charger will ruin the battery.

They are very small agm batteries in there no bigger than 17AH and probably smaller on that model.

If you want a big one for starting big engines get a clore jump and carry JNC660.

http://www.amazon.com/Clore-JNC660-Jump-N-Carry-12-Volt-Starter/dp/B000JFJLP6

 

[CourierDriver]

Looks like you are at a video arcade place

 

[4wheeldog]

Originally Posted By: 79sunrunner
p.s. I learned 750 amp isnt enough to turn over a Jaguar v12 engine

I find that interesting, since the battery demand is really based on cylinder size, more than total displacement. And a Jag V12 really does not have large cylinders. Lots of them, yes, but still little bitty ones. (Only 1 cylinder at a time is actually compressing mixture.)

A bad battery in the car can make jump starting nearly impossible, if it sucks the juice out of the jumper battery, instead of allowing it to go to the starter.

 

[901Memphis]

I'm not surprised that the peak unit can't jump start his jag, I bought the same one on clearance before and took it right back it sucked. The unit is a feather and obviously doesn't contain a very large battery big enough for most needs. I took mine back because it wasn't holding a good charge dropping down from 100 to 90% after sitting for only one day.

 

[79sunrunner]

I think the battery in the car was very poor, when I pulled the positive post off, I pulled it accidentally straight out of the case. I just bought this car yesterday, a '83 XJS, and I flip Jags, MGs, and resell. I could do other cars, but Jags are my thing.

Going to Interstate today to pick up the proper battery.

 

[79sunrunner]

Originally Posted By: 4wheeldog
Originally Posted By: 79sunrunner
p.s. I learned 750 amp isnt enough to turn over a Jaguar v12 engine

I find that interesting, since the battery demand is really based on cylinder size, more than total displacement. And a Jag V12 really does not have large cylinders. Lots of them, yes, but still little bitty ones. (Only 1 cylinder at a time is actually compressing mixture.)

A bad battery in the car can make jump starting nearly impossible, if it sucks the juice out of the jumper battery, instead of allowing it to go to the starter.



Exactly! This jump works excellently on other cars such as Fiats, and MGs, and it even started a completely dead 5.0 liter Mustang!

 

[1 FMF]

when you say you learned that 750 amps is not enough to turn over a jag v12 engine, that is a bit incorrect.
first to say so many amps of current without giving a voltage means power is unknown.
Power = volts * amps.
as always with marketing, they mislead you and advertise a large number. the car electrical system is 12 volts, generally you need 10 volts minimum otherwise things simply don't work. if you have less than 10 volts, the starter solenoid won't work.
so 10 volts * 750 amps = 7500 watts of power not counting efficiency loss. if that charger plugs into a 120v wall outlet, having a 20 amp circuit breaker, you are limited to 2400 watts of power. where is the other 5000 watts of power coming from?

most car starters are rated around 1.7 kilowatts, and draw around 100 amp. if you were to just be practical and look at the size of the starter and look at the size of copper windings within, only so much amperage can go through it otherwise it would melt. using 750 amps of current is up around what DC traction motors use on a locomotive.

this reminds me of pulstar spark plugs, the 1 million watt spark plug they said.

 

[CourierDriver]

In the old days of 1970's were I spent some time at the old Goodyears stores, we sold batteries, and the rule of thumb then ,way before all the days of electronic this and that,,,,the rule for a good battery fit was: Match the cold cranking amp rating on the battery to the cubic inches of the motor for V8s, back then.. today,,,,dunno if thats true, but it worked then...

 

[wrcsixeight]

The batteries in these jumper packs are usually just 12 AH capacity AGM batteries like this one, which also has the charging instructions on the side differentiating Cyclic and standby charging requirements:

http://www.amazon.com/gp/product/B0079KW...80RDNG1TZ73MQSG

The larger ones have 18AH capacity batteries and I imagine the super HD ones can have even larger batteries.

http://www.amazon.com/UPG-UBCD5745-Seale...cid+AGM+battery

While charging through a ciggy plug works, hooking a depleted battery to it, can blow the Ciggy plug fuse.

Fully charging a battery to 100%, from 80% takes hours, about 4 hours at the Absorption voltage listed on the battery, which is 14.6 to 15.0 on the UB12120. Getting the battery to 100% is important for its lifespan. If it lives at 85% charged, it will lose capacity much quicker. One cannot speed up this ~4 hour 80% to 100% charge time. It is the nature of lead acid batteries.

The provided wall wart chargers with these jumper packs are not known to charge them ideally. Leaving them plugged in for several days might do it, or it might not.

Lead acid battery charging is not as simple as throwing a charger on it. 99% of people have no idea the requirements of a lead acid battery when max performance and longevity is desired.

Ideally you want voltage to remain over 12.75v for days after removing the charging source on such an AGM battery. If it falls below this, either it was not fully charged, or the battery is capacity compromised to some degree, likely from chronic undercharging.

Perfectly charging the UB12120 battery would require a 2.5 amp charging source until 14.7V is reached, and then 14.7v would be held for 3-4 hours, then the charging source would drop to 13.6v or so for floating/ maintaining the battery at full charge.

Putting a 13.6v charger on it will take much much longer to fully recharge, and possibly might never fully recharge it.

These wall wart DC power supplies provided with these jumper packs are not designed with logic circuitry for 14.7v for 3 hours and then dropping to 13.6. Holding 14.7 for too long would overcharge the battery and blow the vents. 13.6v will not, and is safer, but takes significantly longer and might not ever truly fully charge the battery.

A "smart" charger on the 2 amp AGM setting will do a much better job than the provided wall wart. Bleeding off the surface charge and restarting the charger will get it closer to 100% charged, as automatic 'smart' chargers are also afraid to fully charge a lead acid battery.

The blinking green light only indicates the charging source has decided to quit, or greatly reduce voltage and thus charging current. It DOES NOT mean the battery is fully charged, despite the mumbo jumbo the marketers would like you to believe.

Colder temperatures change required charging voltages greatly, so Such a charger left in a cold garage is not going to properly charge the battery. A proper float voltage on a flooded wet battery is 13.2 at 80F, but is 14.37v at 10F. Likewise temps over 77F or 80F require lower charging voltages.