Best battery review I’ve seen. You will be surprised.

Dalehelman

What this independent test found out about AGM batteries can save you dollars.

https://youtu.be/iy3hga_P5YY

4ncar

Good stuff, but, I think the general consensus has always been that lithium is less expensive when you consider “life cycles.”  Most folks (including me);are sticker shocked on the upfront cost. I opted for 2 6v flooded.

webers3

Very good, extensive testing. Independent? No. It was funded by Battleborn

ChanW

Very interesting. I guess it's good I was ignorant of this info when I purchased our two 6v GC flooded batteries. Though I do regret the weight, I don't regret the initial investment savings.

I wonder how long the heating elements are warranted for. Seems they could be a life-limiting feature for the heated Battle Born batteries, unless they're well made.

Marceline

I think that the findings about the AGMs aren’t really surprising. This isn’t very sophisticated technology so I don’t know what people think they’re getting from more expensive AGM batteries. But I'm a bit surprised that the batteries didn’t perform as advertised. 

DougH

I believe the manufacturers estimates for number of possible charge cycles as tested using 20h assumptions, etc.

But it wasn't clear from the video when doing the 8A or 80A discharge testing whether they were concurrently charging as if a solar system was present.

The presenter correctly pointed out that AGMs that are taken to well below rated 50% capacity, and not immediately recharged, have a shorter number of remaining cycles. That's been noted several times on this forum.

But I never use a continuous 8A or 80A discharge rate.  Only under cloudy conditions do I take my AGM battery bank down from 100% to 90% and then not get out of bulk for several days. I would never take the bank down to 50% or 40% in those conditions.

Much more often I'm using a few amps sporadically for the fridge, or a fan. And then occasionally running 50A for appliances, but usually in the presence of strong solar.  So the Victron controller output shows a bulk, absorption, and float phase for every single day.  And it's discharge a little, charge a little, discharge a lot, charge a lot throughout the day, with the only long term low discharge being overnight.

I didn't see that this is how the testing was done on the video. So I don't yet have a warm fuzzy feeling that this was real world testing

I used to have two 125Ah batteries for my 2017 T@B plus a small independent original flooded battery, and now I have just three 125Ah AGMs as of last year.  I'm not a full-timer yet, but have taken dozens of trips each year.  So far haven't seen any degradation of the bank, and would feel safe pulling the 375Ah down to 60% (150Ah) if in strong solar conditions. For $750.  I'd need to spend $1500-2000 to get the same from two lithiums.  I'm only at four years, and maybe the bank will die at six... versus two battleborns would go to ten years.

But I'm not convinced that in real world conditions where a person has 200W solar with 200Ah batteries... or 300W solar with 350Ah batteries, whether we know in real RVs with prudent owners and good battery monitoring whether lithium and AGM might both turn out to have six or eight year lifespans.

Verna

I chose two 6V AGM batteries for my new 2021 T@B 320. They will last as long as they last, and I have enough solar to keep them charged. 

At the time I ordered the 320, there were so many questions and not enough answers about Lithium batteries (still is, IMHO). I chose to stick with what I knew would work, and in 5 to 7 years (or whenever they die), then the Lithium technology should have have grown to the point that the price drops and the questions are answered. As quickly as the lithium battery technology has grown, there might even be a new type of battery technology by then. 

Sharon_is_SAM

I am glad we have so many owners opting to be beta testers for the lithium batteries.  We will have good, real world experiences to offer forum members.  There are so many ways that owners use their campers and batteries that a one-size-fits all mod is not yet apparent.  Hard to justify the cost for owners who predominantly camp with shorepower.  

Denny16

For me Lithium batteries are a goods choice if you are Boondock/free camping, and have solar charging for them.  Or camp away from shore power sources, Nd the battery power is your only source.  

For RV camp ground use, where you have 120VAC Shore power available, and only use battery for transit from one location to another, then traditional flooded or AGM batteries are a better investment, and would meet most needs.  

For AGM vs Flooded cell, battery maintenance required for flooded vs plug and play of AGM (and Lithium), the later have a confidence advantage, and more battery location options over flooded.  

Cheers

db_cooper

I find it hard to justify the cost over 2 6v  GC's.  I'd only switch to AGM or Lithium if I were moving the batteries inside.  Out in the tub, I don't have to worry about them being stolen.  I'm kind of hoping someone will steal the GC's in a year or so , so I don't have to lift them to get new ones.

rfuss928

My two 100ah Optima Blue Top AGM batteries (~$800 in 2011) lasted 8 years with the degrading performance only evident in the last year.  They were replaced with a pair of 100ah DuraCell AGMs from BatteriesPlus while on the road.  Under $400 total for both.  I expect similar life from the DuraCells.  

pthomas745

It was an interesting discussion on the video.....but some of the tests were over my head.   It did suddenly dawn on me that even if I don't want a 1000 dollar 100 ah lithium, since I hardly use many amp hours at all....there must be smaller, cheaper lithiums.  There are plenty of differently sized lithium batteries on the market with decent prices,  and many 500 dollar 100 AH lithiums.  For some owners, (like me) a 400 dollar 50AH battery would work out well.  I carry around a small 30ah battery as a "utility" battery, and I see a 12AH lithium on Amazon for $120 dollars that weighs only 4 pounds.

So, today I learned there are many different options on lithium batteries that may not include 1000 dollar Battleborns.  The test I would like to see is how well a 50 AH lithium does for a low power use/propane fridge/solar panel camper like me.

NovaTab

there are a few tested that are very good in the $550 range

See https://www.mobile-solarpower.com/lithium-batteries.html

Marceline

db_cooper said:

I find it hard to justify the cost over 2 6v  GC's.  I'd only switch to AGM or Lithium if I were moving the batteries inside.  Out in the tub, I don't have to worry about them being stolen.  I'm kind of hoping someone will steal the GC's in a year or so , so I don't have to lift them to get new ones.

It's probably hard to justify lithium for a lot of people. For me, weight was an enormous factor. People tend to forget about that. 

Verna

db_cooper said:

I find it hard to justify the cost over 2 6v  GC's.  I'd only switch to AGM or Lithium if I were moving the batteries inside.  Out in the tub, I don't have to worry about them being stolen.  I'm kind of hoping someone will steal the GC's in a year or so , so I don't have to lift them to get new ones.

@d@db_cooper, I’m chuckling only because I had a young man, a personal trainer/landscaper, who helped me by lifting my two AGM batteries out of the front tub, waited for me to install the battery box straps , then he lifted the batteries into the new battery box.  It sure is nice to take advantage of my brother’s strong friends!

TomCanada

From everything I read, lithium batteries are only truly compelling from a cost perspective if you keep them for a LOOOoooong time (years).  At that point they totally are worth the investment because they simply last longer.  But I think people overestimate how long they'll keep their trailer.  I find it amusing how Patrick from the Travels with Delaney youtube channel spent >$2000 on 100Ah of Battleborn, new converter, etc. early in 2020 only to sell his trailer a few months later lol.  And that guy goes through trailers like candy - he's on his 10th trailer in 15 years, so he should've known - who knows, maybe he got some of that stuff for free - just speculation  

Anyways, I'm completely happy with AGM.  You can actually take them down to 20% charge on occasion very safely without permanent damage - granted, the lifespan at repetitive 80% discharges is around half of the lifespan at 50% discharges, so there's a bit of a hit, but the fact that you can safely on occasion go down that low negates one of the lithium arguments, and I'd rather replace the cheap AGMs every few years than go all out on lithium.  I think I'd rather spend on a solar upgrade to enable better boondocking.. not saying there's anything wrong with going to lithium, just seems pricey..

webers3

Can anyone recommend at least 100ah AGM battery that will fit in the 320s original battery slot? ie: I don't want to do any major modifications in the tub area.

4ncar

I needed the additional tongue weight the 2 GC batteries provided to offset my bikes on the back.

Olena

This is a comment for Webers3. I looked around to find the most ah I could without having to modify the original battery slot, and ended up buying an 88ah lithium by a company called Enerwatt (it fits a group 24 space). Enerwatt is a Canadian company and the battery is made in China. The price in Canadian dollars was $679. It was the best deal I could find for the parameters I had set. Lithium is not new for me since I already own a Goal Zero Yeti 400 as a portable power station and have been very happy with it. I don't winter camp so the cold weather concern with lithium is not an issue.

The Enerwatt is for sale at a website called Solacity.com. Check out their amazing head office made of straw bales!

CrabTab

@webers3, A group 31 size battery fits in the tub with no problems. The Renogy 100AH AGM is that size. We own one and would purchase again.

webers3

Thank you @Olena, will look into it

Olena

We have a group 31 AGM here at the house for our sump pump and I can't lift it - It's over 70lbs. I'll admit that I have lady arms, so the group 24 lithium weighing in at 23 lbs gets two thumbs up from me! I guess one doesn't really need to be able to lift it, but I like having the option.

rh5555

I have no idea where he got the idea that the 50% discharge point should be at 12.2V while under load.  This makes absolutely no sense - the cell voltage of an AGM battery is really dependent on the discharge current.  If you drew 150 Amps from our batteries, the voltage would immediately dip below 12.2V, so he'd conclude that the battery has no capacity whatsoever.

For the nerds among us (we know who we are!), here is the graph of a stepped discharge I did at 40Amps:

The battery was discharged until the state of charge had dropped by 10%, then discharging was halted and I allowed the battery to recover until the voltage stabilized, or I had finished my coffee/lunch/beer, whichever came later.  You can see, the cell voltage drops pretty much instantaneously when the discharge is started, then creeps down as the battery discharges.  That initial drop is caused by the "internal resistance" of the battery - which calculates out to be 0.015 ohms.  Lithium cells have a way lower internal resistance (so don't have this initial voltage drop) which makes them appear so much better in this analysis.

I do not disagree that Lithium is a much better technology, and as the price comes down will dominate this market, but I'd like to see comparisons done on a level playing field.

Denny16

Good point Roger, I was also confused by some of his claims, your graph shows a more accurate look at a AGM discharge and the voltage levels are what I has assumed they would be at the various levels of discharge.   Thanks for posting it.
cheers

ColoradoSun

All I can say is that when I was a kid on Boy Scout campouts, I always expected my flashlight with the big D cells to die before sun up. Battery technology has come a long ways.

TomCanada

@rh5555 fellow nerd here - love the graph. I still wonder how it's possible to even remotely rely on those onboard 4-level battery readouts most rigs have.  I suppose if you just plan on checking before you travel and the battery is rested, it can give you a coarse approximation. But once you start using it, all bets are off.  Battery monitors are an absolute must in my mind, especially since I do plan on (vary occasionally) taking my AGMs below 50% SOC but still want to keep them in a safe range and ensure they last more than just a couple years. 

ColoradoJon

I've been saying this for a while now... lithium batteries are great but at their current cost they are not as viable as AGM or Flooded.  Longevity?  Maybe those lithium batteries will last a long time... but I can still buy two 6V GC2 flooded lead acid batteries many times over for less cost than a similar lithium configuration, and *still* last just as long.  And contrary to popular belief you can discharge AGM or flooded lead acid batteries down to 20% without permanent damage.  If you do this regularly, though, it will decrease the overall life span of the battery.

Weight is a very good advantage to the lithium battery, though, but until the cost of lithium comes down to a reasonable price I'm sticking with flooded lead acid batteries.  The cost just cannot be beat and you get much more value for the money.

Verna

@ColoradoJon, like you, at this time I cannot justify the cost of lithium. I did get dual 6V AGM batteries, and by the time these need replaced, either the lithium or the newest battery type should be at an affordable price. 

webers3

@verna I would like to see how you placed the batteries in your 320

Verna

@webers3, the batteries are now in a dual battery box, and I don’t have to worry about dropping anything across the terminals. 

webers3

@verna Great, thanks. Nice set-up but much larger tub than my 2017 320s