Highest current flow you have seen?

[CougarCouple]

For those of you which have the ability to see the amount of current flowing in and out of your battery’s have you seen numbers higher than 60amps.
I’m asking because I picked up Thornwaves blue tooth Monitering devices it has built in current sensing but good only to 60amps. Can go external but do I need to. 150 watt solar, 30amp charger from shore power and truck alternator, which I saw putting out 9amps.
Thanks in advance

Russ

 

[Lineman]

I have never seen anything close to 60 amps. I have 300 watts of solar and normally see a max charging amps around 20. I have never checked it in full sun with the truck running, but I would be surprised to see more than 30 amps.

 

[Vic Harder]

once i did a test run of my system, running the batteries down to 50% (230 AH capacity) and started the truck. 80A is what i saw during Bulk mode

 

[craig333]

Using the camper batteries to jump start nearly dead truck batteries I've seen 80 amps. Enough to make me concerned about the 100 amp shunt.

 

[Optimistic Paranoid]

A 1,000 watt inverter will be drawing 83 amps from the battery bank at full power.

 

[craig333]

My inverter is the one thing that doesn't get measured.

 

[CougarCouple]

Thank you all for you input.

Russ

 

[Vic Harder]

was out for 4 days, camped in the shade last week. 230AH battery bank got down to 80%, meaning about 46AH were drawn down. I drove home for 90 minutes, sustained 30A or so going into the batteries (high of 50, low of 20) all the way. Batteries were at 90% when I got home. The math doesn't work for me, (1.5h at 30A = 45AH, so why only 90%)??

Still, gives you an idea of max currents. Oh, in case it is relevant, 100A fuses on both ends of 2g welding cable from alternator to camper batteries.

 

[Optimistic Paranoid]

Well, I'll make one observation.

People tend to think of batteries as being analogous to fuel tanks for electricity. If you have a ten gallon fuel tank, and use five gallons from it, if you put five gallons back in, it's back to full.

Batteries are actually chemically powered generators. When you recharge a battery, the electricity causes the chemical reaction to reverse itself. It actually takes MORE electrical energy to cause that chemical reversal than the amount of electrical energy you took out of the battery in the first place. On average, about 110%, although it can take as much as 115% on some batteries. Or to use simpler numbers, if you took 50 ah out of a 100 ah battery, you'll probably need to put 60 ah back in to bring the battery back to 100%.

This may not be the ENTIRE answer to what you saw, but I'll bet it was a good part of it.

 

[CougarCouple]

OptimisticParanoid
That is interesting, I did not know. Thanks for that.

Vic thanks for the real world info. When you mention 2ga, got me to wonder. Marty hooked up our truck to the camper. 10ga wire with a 30 amp fuse on the hot. Maybe my problem is solved. If the battery tries to take more than 30amps fuse will blow and provide protection for the Bluetooth monitor I purchased.

Russ

 

[PaulT]

230AH battery bank got down to 80%, meaning about 46AH were drawn down. I drove home for 90 minutes, sustained 30A or so going into the batteries (high of 50, low of 20) all the way. Batteries were at 90% when I got home. The math doesn't work for me, (1.5h at 30A = 45AH, so why only 90%)??
.

Check your “Charge Efficiency Factor” setting in your Victron. Default apparently is 95%.

Paul

 

[Vic Harder]

yes, it is. Seems like a reasonable number. More importantly, the batteries were still taking a charge, so they were obviously not full yet. Plus I imagine the "efficiency" of the charge varies with temperature and age too.