Charging House Batteries while Driving

ted 95 · 01-07-2018, 04:48 PM

This is just an FYI.
We came down from the frozen north (Canada) last week.

It was -20f when we went to pick up the unit. All was frozen solid. We had to keep running the gen to keep the batteries charged so with that we thought the batteries had froze and no longer were holding a charge. Well after we arrived at the camp ground and did a little more digging I discovered the 30amp charging fuse from the truck had blown.

Can't figure out what might have caused it to blow. I have reconnected the unit and nothing causes the fuse to short. The only idea I have is we towed a friends cargo trailer a month ago

Any suggestions????

Also found this on line and think we should all carry one of these. It is a 7 pin tester

https://images-na.ssl-images-amazon....S400_QL65_.jpg

robkathybat · 01-08-2018, 12:51 AM

If the friends cargo trailer did not have a battery then the fuse would not have blown. If it did have a battery and it or your house batteries were at a low voltage, or discharged, then it is possible the 30 amp fuse blew because the truck tried to charge the battery flowing more than 30 amps. The power law is P=VI P is power, V is voltage and I is current. For the same power if Voltage goes down then current has to go up.

ted 95 · 01-08-2018, 03:17 PM

That could make real sense as the unit was one big ice cube. Nothing worked till we put a garage type charger on the batteries. Will post later going to borrow a load tester this morning. They have been charging for a week now and want to see if they can hold up
Thanks for the input.

watersmk · 01-17-2018, 06:04 PM

When my GMC kept blowing 30 amp fuse to trailer 7 pin, it turned out it was the batteries in the trailer which were too low (as stated above P= V * I). Replaced batts and worked fine. Frozen batts would react the same way.

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XCMARK · 01-19-2018, 12:59 AM

my last 3 GMC 2500 and 3500 diesel trucks have had 50 amp maxi fuses to the rear plug. Check the fuse box under the hood for the correct size it should have in the trailer slot.

ted 95 · 01-19-2018, 01:55 AM

mine has a 30A under the hood that was blown

mhs4771 · 01-19-2018, 02:58 PM

My '11 Silverado had 40 amp fuse which blew once in seven years of towing. Guess I'll have to check and see what size this new '18 has.

xtasee · 01-19-2018, 03:20 PM

Quote:

Originally Posted by mhs4771

My '11 Silverado had 40 amp fuse which blew once in seven years of towing. Guess I'll have to check and see what size this new '18 has.

Michelle,

I knew you were thinking about a new Truck but did not realize you pulled the trigger.

I am sure you have experienced the upgrade in performance. Upgrading my 2010 to the 2017 was a significant change.

I hope you enjoy yours as much as I do mine. I am almost having a love affair with this truck....

mhs4771 · 01-19-2018, 04:26 PM

Well the BIG test won't come until May when we hook-up to head back North, but it will give me a while to at least put some miles on it before towing this Heavy Beast of ours.
Still learning all the new switches.

xtasee · 01-19-2018, 09:30 PM

Quote:

Originally Posted by mhs4771

Well the BIG test won't come until May when we hook-up to head back North, but it will give me a while to at least put some miles on it before towing this Heavy Beast of ours.
Still learning all the new switches.

You will also notice a huge difference with lower RPM due to the higher torque. Better Fuel economy and the big one for me is Temperature stability. I do not see the Temp gauge swings and have the Fan Clutch kick in like the old truck.

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