Jump start from deep cycle battery?

[GaryDierking]

If you had to jump start your vehicle from the teardrop's deep cycle battery, would it damage it?

[Shadow Catcher]

No it is actually much tougher than the vehicle battery, which does however put out more amps more quickly i.e. cold cranking amps CCA.

[bdosborn]

From the NAWS Site:

Using a deep cycle battery as a starting battery

There is generally no problem with this, providing that allowance is made for the lower cranking amps compared to a similar size starting battery. As a general rule, if you are going to use a true deep cycle battery (such as the Concorde SunXtender) also as a starting battery, it should be oversized about 20% compared to the existing or recommended starting battery group size to get the same cranking amps. That is about the same as replacing a group 24 with a group 31. With modern engines with fuel injection and electronic ignition, it generally takes much less battery power to crank and start them, so raw cranking amps is less important than it used to be. On the other hand, many cars, boats, and RV's are more heavily loaded with power sucking "appliances", such as megawatt stereo systems etc. that are more suited for deep cycle batteries. We have used the Concorde SunXtender AGM batteries in some of our vehicles with no problems.

It will not hurt a deep cycle battery to be used as a starting battery, but for the same size battery they cannot supply as much cranking amps as a regular starting battery and is usually much more expensive.

Bruce

[Bogo]

You can let the deep cycle battery partially recharge the dead battery, by leaving it jumpered for 10 to 15 minutes. before trying to start. The energy deposited into the vehicle starting battery will mostly be surface charge, and available for starting.

[DTCOOPER]

In order to "Charge" a battery, current flow must take place. Unless there is a large disparity between the "dead" battery and the deep cycle battery, you're not going to experience very much current flow at all.
That's why a charger or alternator puts out as much as 15-16 volts...

At best, hooking a fully charged 12.8 volt battery, to a "Dead" battery with only 10-11 volts is going to equalize the two.
"Jumping" with the deep cycle battery in essence uses the deep cycle for turning the starter... And as someone said above: this will work usually. So long as the starter isn't drawing a huge load.

On another note- A BATTERY CAN NOT "PUSH" CURRENT... Current can only be drawn. I know it's a matter of semantics. But it does matter.
You could use the battery out of an army tank to jump start a YUGO.. The problem comes in when the vehicle is started, and the alternators (voltage regulators) start "fighting" each other.. That's why no matter what you're jump starting; it's best to unhook the vehicles IMMEDIATELY upon starting.

[jeffmutch]

This is slightly off topic but some might like the idea...

I have a bad habit of falling asleep in the parking lot with the radio on. When I woke up to a dead battery the third time but didn't want to buy a new one quite yet, I realized that with the solar panels installed for charging the ttt's battery, and the wiring from the truck designed to charge the ttt's battery also... I simply unhooked the deep cycle battery, but kept the group of wires clipped together, waited 20 minutes and off I went.

There are many advantages to solar but this was not one I had considered when I invested.

I have since purchased a new starter battery with a "reserve capacity" so I havent had to use this Idea for a while, but like to know it's there when I'm boondocking far from the rest of civilization.