New Agm Fullriver Dc85 Battery On The Way

HAHA --- I'm not a designer, at best I'm a hack. But I've found 3d printing to be the most useful tool that I think I've ever purchased. On this project I've used it at least twice.

Of course, the weather just shifted and the temperatures are dropping Oh well. So much for a field test.

 

Steve, what charger are you using with the DC85?

I use more than 5 amps and found the standard charger simply didn't work, and upgraded to the 10. There's a flaw in the 10 amp firmware for our use case anyway.

For lead acid deep cycle batteries, the 10 amp charger from noco does a bulk charge, then rates downto trickle, not detecting when the voltage drops and remaining in trickle. Seeing after some time the battery drop, it believe the battery is defective and stops charging altogether. So, you need to power cycle the charger every day or two to keep the battery charge. The same problem would exist if you have a high draw and the bulk load doesn't charge the battery fast enough.

I think the LION battery controller stops all charging, then will allow allow a new bulk cycle when the battery gets to 80%, and it 'fakes out' the charger -- I can't confirm this, but in talking to Van he said his fluctuates like that. Since I'm not going to upgrade to LION I may want to drop a different charger in....but before I do, I want to make sure its designed more like an onboard "converter" for the RV rather than a charger like the NOCO or Battery Tenders of old.

I also considered just putting a 13.3 volt power supply in its place and running wires to the solar controller, which seems to handle this much better and charge very fast....This may be my final solution for the problem.

With my battery monitor, I am never seeing full charges unless the camper is fully charged and I am using little electricity in the campground _OR_ its in storage. Both of these scenarios are fine. Its the "living while camping" that causes the error condition...

SO...hows you're charger working? I may be pulling gout the 3d printer again and making a new mounting plate, and "opening up" the camp in cut hole...which I am not looking forward too.

 

I ran an informal test in the garage last week. I left a light on inside the camper with the camper plugged into AC. The battery got down to 45% after a couple of days and the charger never kicked in. Only after I unplug and replug into AC does the charger kick in. A friend of mine who has lithium has experienced much the same.

 

Ok...that's pretty much my experience too. You're using the noco 10 right?

I'm printing up a Victron template right now -- to see how sizing will work. I don't want it to be inside the cabin; I like the 'Built in' look of the campinn. Hopefully not too much cutting involved

I am also thinking that something like this could feed the solar charger. It's a small, 10-amp powerhouse. Just run the lines back to the solar charger. I may put a small muffin fan on it just to move some air as well. I'd just need to make an insert (again, 3D printed) to keep the 'wet side' dry.

I know that they use a piece of PVC to route wires from the solar down to the battery bay, it should be pretty feasible to pull 2 more 10 or 12 ga wire through it. This of course assumes the solar controller doesn't suffer the same design shortfall. May need to jerry rig 12 volt to the solar input and see...I think I've got everything I need here....

 

I believe it is the NOCO 10.

 

I have experienced the same plugged in the garage- lithium battery as well. It’s like it goes to sleep and needs a reboot every now after then.

 

Sorry Sweeney. I have been a little "unplugged" from the forum lately.

The 3 on-board chargers I have are the:
1) Renogy DC-DC 30A (set to a maximum Bulk 20 amps)
2 A Sunsport6 for the 100W solar panel
3) the Victron IP67 7A charger

Everything seems to be playing well together, with nothing kicking out prematurely, or failing to recognize a battery voltage drop, or failing to kick in at the proper charge stage. Charge times seem reasonable, without having to go to a higher charging amperage, or modify any of the internal wiring.

We did a 4-day dry-camp last week and kept the Dometic going the entire time using the DC85 and my 34Ah portable lithium, with enough juice left in both batteries for at least another day of conservative dry-camping. We were in canopied forest with about an hour of unshaded sun each day, occasionally chasing the sun around with the panel to top up both the lithium and the trailer battery:

View attachment upload_2024-8-19_9-13-45.jpeg

The Victron shunt, I have found, has been less useful as an in-out "%age remaining" gauge than I had hoped. Which is mostly due to the difficulties it experiences in measuring, with multiple input sources, combined with a simultaneous draw. However, its ability to "describe" to me what each charger is doing in the moment (and when it is finished its job) is far more instructive and useful. Its open circuit reading allows me to compare and average with the Renogy's reading, and the Camp-Inn volt meter. I expect that I can get a good "ballpark" figure between the 3 volt meters and never risk going too far below 12.0V to cause any detriment to the battery.

Also: Pretty happy with the Backroads shelter. Though it didn't need to keep any rain off us this time. I played around with various configurations (side-up, side-down, back on the ground, back on poles, cut off extraneous webbing, added tie-downs) and found it to be a pretty good Swiss-Army knife os a shelter.

 

NOCO charger info. OK, this seems to be a often misunderstood item. Lithium batteries do not and should not get a maintenance charge like a lead acid battery does. What the NOCO charger does is "monitor" the battery when it is plugged in. If you have parasitic loads running the lithium battery will discharge even when plugged into shore power. It does this until the battery gets down to about 30% when it kicks in and does a trickle charge. It comes on and does a full bulk charge only when the battery gets down to 20%. In other words the charger jumps in at the last minute and saves the day before the battery shuts it's self down in protection mode.

So, yes unplugging the camper and plugging it back in again will restart the charger and cause it to do a full bulk charge this is not recommended nor needed. Let the battery naturally discharge some and it will be fine. If you are experiencing larger discharging that would indicate that you have parasitic loads running in the background. Three things that need to be done to remove most of the parasitic loads and keep the lithium battery from discharging. One is to turn off the master battery switch. The next is if you have the Autowbrake brake controller you will need to pull the fuse on the Autowbrake, it is a 1ah a day draw on the battery and the master switch does not turn it off. The fuse is a small round quarter turn cap under the brake unit. The third thing is to turn off the TriMetric display by scrolling through to the blank screen.

Cary

 

Great info Cary, TY!
That 1ah/day drain adds up if your rig is in long term storage, and NOT plugged into shore power, or solar roof option is covered by the really excellent CI cover, and AutoW is powered by the bat-tree.

And if you are struggling with fat fingers to get that AutoW fuse off, on the bottom of the case in a nice safe but somewhat inaccessible space like mine (added mounted in right galley storage to a 2010 model in an upgrade in 2017..,)

Well...there is no "need to get a bigger wrench"...just push the fuse cover in a bit and a quarter turn past the detent does it.
Pops right out!

 

Hi Cary, Thanks for the clarification. I am a little surprised it doesn't kick into absorption at more like 50% or 12.0 volts. Since that is the point an AGM/Lead Acids is theoretical "dead" battery. 30% seems a little low to start "last minute" charging. But, you answer makes sense. My parasitic draw is high -- I keep a couple USB fans moving air around inside the cabin, plus the fridge. So I suspect I'm just barely below the "float" output of the noco.

But it at least explains the charging logic.

What logic does the onboard solar controller use? I would guess the goal of it is to keep the batteries 'full' since austensibly and the end of the day, you want full batteries for the overnight. If that's the case, might a solution be to rely on the solar panel system?

 

Great question Sweeney! I generally disconnect my solar everyday; so I’m unknowingly rebooting the following day.

 

Sweeney,

The solar is not generally acting as a maintenance charger so will gather what ever sun it can get a hold of and charge when possible. Sort of "making hay when the sun shines". It will throttle way back on charge when it is not needed but still will always be charging when possible. The NOCO is acting in the plan of long term storage of a lithium battery, different goal. The NOCO is not putting out a "float" when it is configured for lithium. It only monitors.

By the way, the lithium battery is much different on battery voltage. Full charge is 12.8v (vs 12.3 for AGM) and will be dead and turning itself off about 12.6v which is under 20%.

Cary

 

Wouldn't a matinenace charger be just fine for a lead acid/deep cycle? From what I understand, these "old" batteries like to be trickle-charged. I'm also think while at a camp site, where you want to "make hay" even though on shore power, you would never have the 'dip' of nighttime ....

 

Sweeney,

That is correct, a lead acid/AGM battery would generally want to have a constant maintenance charge taking place. The newer generation of chargers will typically not constantly charge but rather monitor and keep adding periodically to maintain a float charge. That is easier on the battery than the old trickle chargers which tend to just apply a constant small current. If using a wet cell battery (like in an airplane) for example an older style trickle charger will evaporate out the water over time much quicker than it should. Switching to one of these newer chargers like the Guest that we use today is easier on the battery. Had to make that charger change for the maintenance charger on my plane because I was evaporating the water out.

You are also correct that the solar charge during the day dropping off at sunset works great because it leaves the battery with a pretty high float charge that carries through the night nicely. With a good solar system that is being operated all day the battery really never gets below a float charge which is really really easy on the life of the battery. With the lithium battery it is really different because it maintains such a constant voltage it is really hard to apply any of these metrics to it.

Cary

 

Cary,
The next time you need to replace your wet cell battery in the plane, you might want to consider an AGM. There are Odyssey batteries approved for certified aircraft now. A friend has one in his 172 that has been working well.
I have two in the GlaStar since it's all electric. With the backup, the power should outlast my fuel if the alternator ever goes belly up. I think mine have been a little bit of an outlier, but when I did my annual last fall, I looked them up in my air frame logbook, and found they were 10 yrs old, but still passed a load test without a problem, but I will probably replace them at the next annual. The other nice thing is they are quite a bit less expensive than a Concord or Gill, which a lot of pilots feel lucky to 3-4 yrs out of.
SBS J-16 Aircraft Battery

 

Dustin,

That is great to know. Honestly the reason I stuck with the wet batteries all these years is the Concord AGMs are just to rich for me. But, this Odyssey is about the same price as a wet cell so why wouldn't I. Thank you.

And ya, 3-4 years on a wet Gill battery is about right. This is my second Cessna since about 2010 and boy have I bought a bunch of those Gills. I had a gell cell in my old Bakeng Duce that was in it when I bought it in 2008 and I think I finally had to replace in about 2021. Really makes a difference.

Cary

 

Ya, as you know with the Duce, doing upgrades in an experimental to make it better/safer is not a problem like it can be with the certified planes, but FAA attitude on this appears to be changing a little, and holds some promise that upgrading legacy aircraft will become a bit easier in the future.