What size jump starter for 2500 HD (Diesel)?

rustyangel · November 15, 2020

2017 GMC Sierra 2500 HD (Diesel)

Last week, one of my batteries died. (I am embarrassed to admit that I have had the truck for 3 years and only just learned that it has 2 batteries! This is my first diesel...obviously). Anyway, one tested at 12 and the other only at 10. I ended up replacing both because I had heard if you only replaced one, the other one would “pull” against the new one and wear it out faster.

Anyway, when it wouldn’t crank, I got our 1,200 amp jump starter (freshly charged) out of the garage and hooked it up. It wouldn’t start it! I left the thing on there for like 10 minutes...nothing. I had to back my wife’s care up and jump it off using that.

I want to buy a heavy duty starter capable of starting it. What do I need? I see thy make 1,500 and 2,000 amp units. I assume those are powerful enough?

What do you have and do you like it? How much did you pay for it?

davester · November 15, 2020

I would double check that the cables have a good solid, tight connection to the batteries. Two new, correct batteries for it should easily do the job.

Actually, first, what do you mean by not starting? It's not turning the engine at all, not fast enough, or turning over fast enough, but not starting?

rustyangel · November 15, 2020

I got both batteries replaced so I’m good now. I just want to avoid this issue in the future, so want to buy a jump starter big enough to start my truck if one of the batteries does in the future.

davester · November 15, 2020

Oh, ok. Depending on how the battery dies, you may need to determine which battery is bad and disconnect it in order to start the vehicle.

I've had a car battery fail, so that with another fully charged battery, as well as my truck hooked up to the car, and it wouldn't spin over the engine, but once I disconnected the battery, it would fire right up.

rustyangel · November 15, 2020

Gotcha. So I need to invest in a battery tester and hook it up to each battery to see which one is bad if/when this happens again?

(Note: this seems like a lot of work at 4:30 in the morning when I’m trying to get into the woods for the morning to go deer hunting...LOL!!)

I just want to jump and go (if that’s possible) and take the portable jumper with me so I can start it again if necessary. I know it’s not a long-term solution and I’ll get the battery replaced as soon as I can. I am just looking for an emergency situation, temporary fix.

I appreciate your input!

dplarson · November 16, 2020

And have tools to disconnect each battery so you can check voltage of each one separately.

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davester · November 16, 2020

IDK what size booster you need for your truck, it's good to have one with you in the middle of nowhere, and they work fine if your batteries are just low. But if the battery has gone bad...

rustyangel · November 16, 2020

10 minutes ago, davester said:

IDK what size booster you need for your truck, it's good to have one with you in the middle of nowhere, and they work fine if your batteries are just low. But if the battery has gone bad...

Right...but, in this particular situation, the battery hadn’t completely gone bac. It had just lost some juice. After I jumped it with my wife’s car, I drove an hour and cut it off. It sat there for about 4 hours and then started right up. That tells me the battery was just a little low.

All I am after here is what size (in amps, I guess) portable jump starter I need to make sure I have enough juice to get it going? Obviously, if the battery is completely dead, no amount of amps will start it. My assumption is that a battery dies over time and so I just need some recommendations to get it going in emergency situations.