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02-10-2023, 03:50 PM
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#1
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Member
Join Date: Dec 2021
Posts: 34
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Puzzling battery/charging
We have a 2022 Dynamax Isata 3 with the Lithium battery option (2 ReLion 100 AH batteries, RB100-LT).
In early October, I picked up our RV, brought it home, leveled it in driveway, connected shore power. In the afternoon, I disconnected power, parked the unit down at our clubhouse overnight (HOA rules). Unknown at the time, the main valve on the propane tank was in the off position.
In the morning the lithium batteries were drained. With the propane off, and the fridge set to “auto,” the fridge (along with other background systems) apparently drew power from the batteries overnight.
I posted about this previously, and appreciate the many comments/posts received.
Since then, I have been learning the Victron Connect App, have noted a number of things, and have questions.
After a short trip in late October, the RV was returned to indoor storage with shore power “on,” but house disconnected/off. (No solar charging).
These two images show roughly sequential 14-day periods.
The jump in charge was from the RV being started and moved to a new location within the storage facility.
The battery then shows a continuous voltage drain over the next few weeks until about December 3.
At 61%, the Victron apparently “lost signal,” or BMS went into safe mode, I’m not sure which.
On a 30-day graph it looks much more rapid (this is also voltage, not charge).
The next month, on January 4, I returned to the storage facility and checked the batteries, noting the graphs and battery drain above.
The voltage on arrival was about 10.77 volts.
The 5-hour graph below shows the low voltage starting a few minutes after the storage unit staff starts up the engine, moves it out into the sun for me to pick up about an hour later. So I presume the voltage was rock bottom and only topped 10 volts after the engine had a few minutes to add charge (and perhaps some from the solar panel).
When I arrived, I started the engine, the voltage promptly rises. Over the next hour or 2, I kept the RV or generator running at all times.
When I returned the RV to storage after lunch, we put the RV back inside, left the house on, but did not connect shore power at first.
I called back later in the day, and the staff reconnected the shore power (so, house “on,” shore power “on”) at about 3:53 PM.
On January 24, I returned to the storage unit and checked the battery.
This images below show a 24-hour period from return to storage at 13.63 volts, then reconnection to shore power.
During that brief period of a few hours the batteries dropped from 13.63 down to 12.88 volts.
After shore power was reconnected, the voltage recovers.
This 30-day graph below shows the RV with shore power “on,” house “on.”
The initial drop in voltage I believe is during the afternoon of January 4 when it was off shore power, house “on,” shown more fully in the 1-day images above this. When the shore power was restored and house left “on,” the batteries maintain charge/voltage.
Questions: Is this degree of voltage drop/loss of charge normal when off shore power?
Is the voltage drop indicative of a bad lithium battery pair?
What am I missing?
Thanks for any insight and advice,
Ed
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02-10-2023, 04:22 PM
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#2
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Site Team
Join Date: Jan 2007
Location: Goodyear, Arizona
Posts: 33,774
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Moved thread to the Dynamax sub-forum for better help from other Dynamax owners and factory reps.
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and Zoe the Wonder Dog(R.I.P.)
2016 PrimeTime TracerAIR 255, pushing a 2014 Ford F150 SCREW XTR 4x4 3.5 Ecoboost w/Max Tow Package
4pt Equal-i-zer WDH and 1828lbs of payload capacity
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02-10-2023, 05:28 PM
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#3
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Senior Member
Join Date: Apr 2022
Location: Tarpon Springs FL
Posts: 3,446
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They do have a steep curve at a the start / finish of the charging cycle
---------------------------------------------------------------------------------
here is a pretty good explanation on Lifepo charging
BUT NOTE ... most of the explanation is talking about the individual cells at 3.2v
4 of the cells are placed together to make a a 12v battery
hope this helps you understand the technology better
recommend you browse though some more of this guy's video for other good info
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Tarpon Springs FL
2022 Salem 24RLXL
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02-11-2023, 10:56 AM
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#4
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Senior Member
Join Date: Dec 2021
Posts: 540
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In the 14 day graph, it showed about a 20% drop which works out to almost 3A draw from the batteries. In the later 24 hour graph the battery dropped 6% which works out to about .5A. Your mileage may vary but on my trailer, the parasites use about .5A with everything off (keeping up with the control boards, etc).
Your charger is sitting at about 14.6V which is the top of the curve. That will drop real quick down to about the 13.5V range with lithium. Voltage is a poor gauge for state of charge. A current shunt gives the best idea of what's going into and out of your batteries.
Simple math, divide your 200Ah of capacity by the amount of draw and you'll know how long they will last.
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2019 Palomino Solaire 147X
2013 Ford F150
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02-13-2023, 11:34 AM
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#5
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Commercial Member
Join Date: Nov 2007
Location: Bristol, IN
Posts: 18,969
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Well, the first thing to note is you seem to be looking at charge voltage as battery voltage.
When the charger is connected the shunt will be reading what they are charging at....so if you plug in a battery at 10V it might read 13.6 immediately. Clearly the battery is not at 13.6 that fast...but the same happens on the reverse. If you unplug from shore power, when it is charging at 13.6v....it will then drop pretty quickly to the nominal/actual battery voltage, which on the Relion is 12.8 Volts.
Relion data sheet here, for more info. https://ceb8596f236225acd007-8e95328...eet_12V-LT.pdf
The discharge profile of a lithium is also unlike a lead acid battery, it will hold that 12.6-12.6 for as long as it can, then it falls off a cliff (unlike a lead acid that is a steady decline).
This is also a good intro to lithium.
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02-16-2023, 03:05 PM
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#6
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Member
Join Date: Dec 2021
Posts: 34
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Sorry for the delay, but thank you for the info...
I presume then that the Lithium batteries are performing as expected, and that there must be a parasitic drain while off shore power (in storage).
And the bottom line is that we will need to keep the RV on shore power with the house "on," while in storage.
If we are dry camping/boon-docking. we'll need to run the generator at least daily (or more often if the Victron unit shows a too rapid charge depletion).
Ed
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02-16-2023, 03:37 PM
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#7
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Commercial Member
Join Date: Nov 2007
Location: Bristol, IN
Posts: 18,969
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It really depends on what is getting left on. There are certainly ways to reduce loads.
The only parasitic draws are slide brains, steps, memory for Firefly. Shouldn't be anything major....but certainly over time it will draw down. It is defiantly not enough that solar would not compensate, unless it is stored indoors.
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02-16-2023, 03:43 PM
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#8
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Member
Join Date: Dec 2021
Posts: 34
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Yes, it's definitely indoors. So no solar gain at all.
Not sure what's causing the drain, but nothing I or the dealer can figure out either (they say they don't have equipment to handle lithium battery issues.)
Ed
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02-16-2023, 04:05 PM
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#9
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Senior Member
Join Date: Apr 2022
Location: Tarpon Springs FL
Posts: 3,446
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to track down a electrical parasitic drain
get a multi meter that can read DC amps. (with a clamp)
Unplug Shore power and any solar panels
clamp the multi meter over the main positive cable leaving the battery
then start pulling fuses....
sometimes it is easier if you have 2 people
one to watch the meter the other to pull fuses
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Tarpon Springs FL
2022 Salem 24RLXL
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02-16-2023, 04:20 PM
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#10
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Commercial Member
Join Date: Nov 2007
Location: Bristol, IN
Posts: 18,969
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Quote:
Originally Posted by DaktariEd
Yes, it's definitely indoors. So no solar gain at all.
Not sure what's causing the drain, but nothing I or the dealer can figure out either (they say they don't have equipment to handle lithium battery issues.)
Ed
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Funny, because that is the 2nd time I have heard that this week. One dealer literally pulled out the lithium batteries and put in flooded for the customer because they did not know how to figure them out. Charged them for a down grade.
A multimeter works the same on lithium or flooded. Power is power.
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02-18-2023, 11:58 AM
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#11
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Senior Member
Join Date: Oct 2017
Location: Quincy, WA
Posts: 1,506
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Quote:
Originally Posted by bclemens
Funny, because that is the 2nd time I have heard that this week. One dealer literally pulled out the lithium batteries and put in flooded for the customer because they did not know how to figure them out. Charged them for a down grade.
A multimeter works the same on lithium or flooded. Power is power.
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That is what occurs when "service" rep has no electrical knowledge and is just a parts replacer.
At another level referred to as an ID Ten T (IDIOT)
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Ken and Kathy Redburn
2018 DX3 37TS (The Taj)
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02-18-2023, 01:59 PM
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#12
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Senior Member
Join Date: Jul 2017
Location: North of Seattle, WA
Posts: 17,330
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Quote:
Originally Posted by DaktariEd
Yes, it's definitely indoors. So no solar gain at all.
Not sure what's causing the drain, but nothing I or the dealer can figure out either (they say they don't have equipment to handle lithium battery issues.)
Ed
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The equipment they were missing is kept between a technician's ears.
When it (brain) is defective all other pieces of equipment are useless.
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2018 Flagstaff Micro Lite 25BDS
2023 f-150 SCREW XLT 3.5 Ecoboost (The result of a $68,000 oil change )
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