Another Battery question

[BeemerJoe]

I have never been good at "Spark Chasing". I just purchased a used 2016 Fuzion 422 Chrome. I comes with 2 batteries. Both 12 volts. Does anyone on here know without guessing if BOTH batteries power the coach or is one dedicated to the Generator? I experimented with powering my Residential fridge with the 1000 watt inverter, and was shocked at how fast the battery drained, but I'm not sure if they were both drained or if only one was. I guess I should have checked them separately with a meter, but only have the voltmeter hooked to one battery. I would love to know how these are wired, but can't find it anywhere. That's the problem with buying used sometimes. If anyone knows, please comment.

[ChuckS]

One battery isn't dedicated to the generator...

How the batteries are wired could be a few different ways since you STATE you powered a residential fridge... I don't think that year came OEM with that type of fridge

Looking at each battery cables will tell you how things are wired...

Yours could be one for the inverter to power the residential fridge or they could be wired parallel feeding the coach and inverter

one battery wont last long with a residential fridge using an inverter to power it without shore power...

[flybouy]

Since your camper had a previous owner the answer would be "nobody but the PO knows for sure". Follow the positive battery cables. If the two batteries are connected by the positive cables then they are in a parallel circuit and are not independent or isolated from each other. The fridge draining the battery(s) may be an indication of the battery state of charge b4ing low when you started out or the battery not being capable of accepting a full charge.

If those batteries are the "typical" rv/marine "dual purpose" type then they are not true deep cycle batteries and are ill suited for the task. I'd suggest removing the batteries, photo the connections, and takebthem to an autoparts store and have them tested. You can greatly improve the performance by changing over to two 6 volt golf cart batteries wired in series. There have been many, many discussions on this throughout the forum.

[JRTJH]

To add confusion to the mix (for illustration purposes only), we've got several posts on this forum from people who use lithium batteries and openly state that when they sell or trade their camper, they plan to pull the "expensive stuff to install on their next trailer" and reinstall something else to sell the trailer. So, with a previously owned trailer, even what you "currently have" may not be the way that trailer was ever used by the previous owner.

The only way I know of for you to find out how your batteries are wired, or even if they are properly wired, is to "chase sparks" and see what's really "under your floor".....

[travelin texans]

Also if the PO put the hybrid marine cranking batteries in they are not the best choice for rv use.
If there's CCA, CA or MCA numbers on the battery tops they are the hybrids.

[BeemerJoe]

Wanted to let all those who offered their advise.. My problem is fixed.
I replaced my two Marine deep cycles. with 4 Trojan t-105's for a total of 450 amp hrs. Installed one group 26 small starting battery for the Generator (isolated with it's one trickle charger"
Charged my trojans and did a test run. With just the inverter and fridge and minor small draws, I ran the system on battery power only.
Got a full 8 hours with the Fridge set to 36 degrees and 0 for the freezer.
Could have easily gotten 10 hours as I was only down to 43% on the batteries. Trojan techs told me no damage would be caused by running down to 20%. As I said. could have easily gone 10 hours.
So in conclusion... all I needed was a better battery pack.. Thanks for all those who helped.

[snoobler]

Originally Posted by BeemerJoe

Wanted to let all those who offered their advise.. My problem is fixed.
I replaced my two Marine deep cycles. with 4 Trojan t-105's for a total of 450 amp hrs. Installed one group 26 small starting battery for the Generator (isolated with it's one trickle charger"
Charged my trojans and did a test run. With just the inverter and fridge and minor small draws, I ran the system on battery power only.
Got a full 8 hours with the Fridge set to 36 degrees and 0 for the freezer.
Could have easily gotten 10 hours as I was only down to 43% on the batteries. Trojan techs told me no damage would be caused by running down to 20%. As I said. could have easily gone 10 hours.
So in conclusion... all I needed was a better battery pack.. Thanks for all those who helped.

Glad you got it sorted. Fellow Trojan owner here.

"No damage" is misleading.

Generally speaking, your batteries have about 1500-2000 cycles to 50%. They probably have less than 500 to 20%.

"Can" and "Should" are important distinctions.

You CAN run them down to 20%, but you SHOULD try to limit that to 50%...

If you're in a bind, and you need all your juice (running a propane furnace at night to keep from freezing), by all means, use it. If it's not a serious situation, try to limit it to 50%.

AND, more importantly, where the heck is that % number coming from? The ONLY reliable way to report a battery's state of charge is to 1) a current-counting battery monitor, i.e., one that says, "You've used 100Ah, so you have (450-100)Ah/450Ah = 77.8% remaining.

or 2) alternatively, and very inconveniently, use a hydrometer to measure the specific gravity of the electrolyte in a battery cell - another reasonably accurate means of determining state of charge.

Voltage is almost worthless as measure of state of charge. The only time voltage is a reasonably decent indicator of charge is if the battery has been completely disconnected from loads/charging for at least 2 hours.

Lastly, if you're running your absorption fridge (can run on propane) on DC or AC, they are HOGS. They use 5-6X the energy compared to a compressor fridge. Use absorption fridges on DC/AC only when absolutely necessary (or on grid/generator). Propane is way more economical than battery.

[BeemerJoe]

I totally understand what your saying, but I'm going by what the Voltage is. I realize it's not totally accurate, but going by what it was with the Marine batteries.. No matter how I measure it, it's definitely better. When I say that it was down to 43% I'm talking 12.5 battery voltage. I've done enough research that I know it's not that accurate, but at least I know that I'll be able to make it thru a night while dry camping without loosing my food. If I have to buy new batteries every two or tree years so be it. Consider it the cost of RVing.

[snoobler]

Originally Posted by BeemerJoe

I totally understand what your saying, but I'm going by what the Voltage is. I realize it's not totally accurate, but going by what it was with the Marine batteries.. No matter how I measure it, it's definitely better. When I say that it was down to 43% I'm talking 12.5 battery voltage. I've done enough research that I know it's not that accurate, but at least I know that I'll be able to make it thru a night while dry camping without loosing my food. If I have to buy new batteries every two or tree years so be it. Consider it the cost of RVing.

"Not that accurate"...

It's not accurate at all, BUT you're being crazy conservative. 12.5V under load isn't anywhere near 43% - closer to 70%+, so you should be good.

Just keep on top of electrolyte levels and SG. FLA batteries can have exceptional life if well cared for. If neglected, you're better off buying AGM.

I think it was someone on this site that said, "Batteries never die. They are murdered." Mostly truth.