I know this is a redundant question for you old Foretravelers/
My U 320 is needing batteries
Are gel Batteries really worth the cost?
I have never had them and I get 5 good years out of acid batteries.
If you have an opinion please let me know.
Rick Maddox
509-939-0740
rlmlimited@comcast.net
Your topic has been well covered on the forum.
Try searching AGM battery or house battery in the search feature You will get hours of material to read Tires and residential refrigerators also have loads of historical threads
My AGM's are dated 2013 and still going strong. Not as cheap as flooded but no vapors or corrosion. I will probably get the ones at O'reilly's when they are done. Too late for me to benefit from lithium and the necessary upgrades cost wise.
Our conventional batteries lasted almost 10 years. Our battery location is open so no worries about vapors. $300 has equaled great service.
Pierce
Where are you located? I have some perfectly good AGMs coming out of my U320 when I convert to lithium in the next few weeks. I'm in Phoenix
Just posted a new topic with an interesting video "Flooded vs AGM vs Lithium. Which is cheaper?"
Might be worth watching
Real World RV House Battery Data...Flooded vs AGM vs Lithium (https://www.foreforums.com/index.php?topic=41471.0)
Pretty good video, worth watching to learn more about cost of energy from your batteries and lifecycle cost. When it is time for new batteries think it through carefully. You may not use all of the life of the LifePO4 batteries but the next owner likely will not have to go out and buy new batteries either.
Well done video except for one thing, I believe they chose to lie with statistics. They were careful to say they used the agm batterie's mfgs 50% charge cutoff voltage, this should have been read as "resting voltage" not taken while battery was drawing amps. The higher the amp draw, the lower will go a 12v agm battery. I believe this makes their conclusions where resting voltage was not used very disappointing for me from this YouTuber and Battle Born. There is no question lifepo4 batteries such as Battle Borns are superior. For this reason I do not know why they chose to mislead with statistics.
I wrongly set the low voltage cutoff on my inverter/charger to 12.2 instead of the factory default at 10.5, not knowing this would throw a fault code every time I ran the microwave and toaster oven at the same time. It was drawing approx 160 amps from the batteries, lowering the voltage below 12.2 on a brand new set of three fully charged 8D AGM batteries, thus causing a fault code. It took a call to Xantrex, and them going thru my settings, to uncover the problem. They explained how even on a brand new bank of 3 AGM 8D batteries voltage would dip below 12.2 volts when drawing 160 amps, thus their recommended cutoff setting of 10.5 volts for AGM batteries on the inverter/charger. Since lithium do not dip as low on amp draw, they reccomended a higher cutoff for lithium. I am sending this to Battle Born to see if they have a comment.
Rick as others have said somewhat more politely, RTFM. However. Gel cells have severe charging rate restrictions. AGM cells can be charged rapidly and the absorbent glass mats help hold the lead peroxides in place. Giving you the longest life as long as you don't overcharge them. Flooded cells take the most abuse but also lose the most plate material when deep cycled. You get about 5 years from flooded cells, 10 from AGM.
In my #3 reply, I was speaking of our engine batteries. Our house batteries are AGMs and twelve years later are still going strong.
Pierce
Jack, did you change the low voltage cutoff only on your inverter/charger? Did you adjust your generator auto start? I will have to check but I think my inverter is set at 10.5 also but sometimes my Generator will kick on if I run the microwave for 5+ minutes.
While in South Florida last week and plugged into a 30amp, the breaker popped sometime in the middle of the night. Had two fans, inverter, and 1 roof a/c fan going. At 5:30am my generator started and woke me up. Irritating but nice to have since I got up and investigated and then went outside and reset the breaker. Not sure how the neighbors in the tent next to me felt about it though.
Elliot,
Are you just changing out the batteries?
What other changes are you making to go to lithium?
Which batteries are you getting?
Doing it yourself?
We're doing the full shebang with a Victron Multiplus 3k, Victron150/100 charge controller, 8 x 180w panels and two Lithionics GTX 315ah batteries. I will help with the install so I know what's going on but I'm paying Gilles at OffTheGridRVs to do it. He did my last install on the 5er and owns a U320 himself.
10.5 is the correct low voltage cutoff setting for AGM or Gel batteries. This is the same I now have mine set to. I do not have auto-gen start. In my post above I incorrectly had set the low battery cutoff to 12.2, and thus was getting a fault whenever I had a high amp draw . According to Magnum remote panel manual auto gen start should be set 1.0 volt higher, 11.5. As I said earlier, Xantrex told me to set low voltage cutoff at 10.5 for my AGM 8D bank which is the Xantrex default.
Safe "how low can I run the batteries" is COMPLETELY dependent on what is going on with the batteries/ when they are reading voltage to trigger generator start.
Most tables show 50% discharge rate WITH BATTERIES AT REST of 12.2 VDC.
Of course under high amp loads even a mostly charged battery can drop to that voltage very quickly. And, yes, voltage will bounce back up when the high load is turned off.
SO, "how low can I go" depends on the above. If it is reading instantaneous readings 10.5VDC is for a short-term reading, that is reasonable. If, however if that is a reading over a longer period of time (where it would be unlikely that you would still have a high-amp draw), that is WAY TOO LOW.