Phantom battery drain

CharlieRN

I have been using a LiFePO4 battery in my 320S BD for some time now (BB 100 Ah). For the past several weeks, the camper has been parked in our driveway with the battery on, but with no devices engaged. While it has not been connected to shore power, the drain has been minimal and the only current draw should have been for things like the monitors and the media display. Periodic checks seemed to indicate that the factory solar was keeping things mostly topped up, but I got lazy and did not monitor things for the past several days.

I was greeted with quite a surprise when I checked the camper this morning however. The first thing that was odd was that I could not get a connection to the SmartShunt. I the looked at the SmartSolar readout, and was surprised to see it say battery voltage was 11.08. A double check with the VOM confirmed the 11.08 voltage reading. When I looked through the SmartSolar history, it showed a min voltage reading of 0.78 yesterday, 071 two days ago and 0.74 three days prior! At four days back, the voltage min was 11.78 but every day further back than that was over 12.65, with most over 13.

While I'm suspicious of those sub 1 volt history readings, there's no doubt that battery has been drained to close to 11 volts. Of course the first question is: Has it been damaged? The next question however is about what the cause of the current drain could be?

Appreciate any thoughts or guidance.

AnOldUR

The first thing I'd check is the fuse between the on-board solar controller and the battery, but I'm sure you've done that. I'm thinking that a history of less than 1v might be a false reading and those days were actually zero.

Can you get a reading of your parasitic drain from the your shunt? If so, what is it? I don't have a shunt, but recently bought something called a Fuse Buddy that's been helpful to find the current drawn through each fuse. I recorded the value for each of the individual fuses in the box, but not the sum of all. I just went out and plugged it into the fuse at the battery (with solar shut off in the app) to see what my actual parasitic drain was. The resolution isn't great, but I'm getting somewhere around .1 amps. Definitely not enough to drain the battery in a few days like you experienced. Recently read something about inverters being a potential drain if left on. Do you have one?

None of this is helpful except to satisfy my curiosity since we both have 320's. Hope someone more knowledgeable come along. The answer could be helpful to all of us.

CharlieRN

OK, I think I may have identified how the history could show less than 1 volt - the BattleBorn internal battery management system.

My guess at this point is that the cloudy weather we had for a few days a while back did not allow the solar panel to charge as usual (history shows minimum voltage dropping from 12.1 a week ago to 12.61 five days back to 11.78 four days ago) and when the voltage dropped closer to 11, the BMS shut things down. This would help to explain why the history shows under 1 volt readings for the past 3 days.

I sent an inquiry to BattleBorn and they will hopefully get back to me Monday to let me know if my guess is correct - or whether I've managed to destroy an almost new LiFePO4 battery . . .

dragonsdofly

@CharlieRN, if your LiFePo Battleborn is that severely depleted (probably not damaged) the battery becomes a very hungry Gremlin! Your solar will not be able to charge it. The battery will demand a lot of electricity the moment it senses anything coming in. It may very well blow the fuse by trying to draw higher than the solar can provide. If that deeply discharged, use your converter to charge it.

We have a large solar system on another trailer (6 100 ah Battleborns) and 1.4 k solar on the roof. We have a 220 amp alternator on our truck, which if the batteries are seriously depleted cannot withstand the draw from the depleted batteries. We had specialized software installed in the truck to interrupt the initial draw to avoid damaging the truck's electrical system. (Our truck is wired to charge this large battery bank so that we are not required to carry a generator). Don't be surprised if that 1 battery is hungy enough to blow some fuses and be prepared.

ckjs

@CharlieRN:

Cloudy days provide way less energy than sunny ones do, so with the typical phantom loads over a week the BB could easily be nearly drained. 

You don’t mention whether the battery switch is now turned to “off”.  Try that and see how the voltage recovers after a few bright days. 

Dutch061

If the BMS shut it off, you will need to connect a 12 volt source to the battery in order to get it to "turn back on" to even take a charge.

It is not damaged, that's what the BMS does to prevent damage. You have a 10 year warranty, no worries.

Brad

CharlieRN

I verified with Battleborn that the BMS shuts things down when the voltage drops to a pre-determined level, before damage can occur to the battery, and that is what happened in my case. As I've explored thing further however, I've uncovered some other issues, one of which is inconsistencies in readings between the SmartSolar and SmartShunt.

My SmartSolar history shows battery voltage dropping by 1/4 volt overnight. This would represent minimal current usage, kind of what I would expect with only the monitors and the Jensen display using power. The SmartShunt on the other hand seems to indicate 20 amp hours consumed overnight, which would represent a huge parasitic drain.How should I interpret this?

The other issue is really more of an observation and that is that battery charging via shore power and the WFCO seems to take a very long time. When I plugged in last night, the SmartShunt read 82% capaciy; this afternoon the reading was only 83%. I would think that 18 hours of charging time ought to have brought things by up more than 1%. I understand that the WFCO in the T@B 320 won't get lithium batteries to 100%; is that shortcoming related to the slow rate of charge?

Dutch061

Since I have a 2020 400 BDL and can't speak to the location of your convertor VS the battery I am not able to provide a clear answer. In the case of the 2020 400, the convertor was way upfront on the curb side while the batteries are under the bed. I installed a new convertor under the bed less than 12" away from the battery power distribution block. This is a major issue when it comes to trying to charge quickly.

I done this before I upgraded to lithium and used a PD9260CV convertor, which is not rated for lithium but has a pendant where I can force the Boost Mode to charge at 14.4 volts for up to 4 hours. It takes 3 if my batteries are nearly discharged. It is important to note that the maximum charge rate for BB is 50% of the battery capacity, so a single BB can only be charged at 50 Amps while 2 can be charged at 100 I am using 60 for the pair and may add 2 more batteries this winter. Still pondering that along with additional solar power. 

Hope this helps.

Brad

CharlieRN

OK, so returning to the original subject of this post, "phantom battery drain", I continue to be perplexed by the electrical goings on in my T@B 320. My SmartShunt registers from 0.25 amps to just under 1.0A, depending on when I check things. That's with nothing on but the systems energized when the battery switch is engaged, in theory, only the detectors and the Jensen display.

Why the variability? And based on what others have found, the parasitic drain ought to be something like 0.7 amp, so what could be responsible for the additional current drain?

AnOldUR

The Jensen system does some funny things depending on the state it's in. Try pulling the fuse that feeds all the audio / video components and recheck your parasitic drain. I put a switch after the fuse which helped.

gulfarea

It is possible that the 2 USB ports are using a little as I believe they are always bringing down the 12 volts into about 5 volts even when nothing is plugged into them. Art

SLJ

USB ports and the two overhead LEDs are parasitic draws.

ontheroad

Is your outside step out..it has a lovely light that stays on unless the step is pushed in...we have a clamp that we use to turn off the light...when set up we prefer a solar light near the step..

CharlieRN

SLJ said:

USB ports and the two overhead LEDs are parasitic draws.

ontheroad said:

Is your outside step out..it has a lovely light that stays on unless the step is pushed in...we have a clamp that we use to turn off the light...when set up we prefer a solar light near the step..

Regarding @SLJ 's comment, the only o/h LED light in my 320 is a circular lamp. It's switched, so should not be drawing any current.

Regarding the outside step, it is in the retracted position (I think I measure it as drawing about 0.3 amps when open). I intend to add a a switch so that the step can be extended but not lighted, though haven't  been able to do that yet. Regardless, it's retracted with no light, so not part of the drain right now.

Even more puzzling is what happened last night. When I checked the SmartShunt just after sunset, it showed battery capacity at 86%. This morning, it read 80%. (the battery switch is in the on position). That would not be surprising except that it is connected to shore power. The converter is definitely connected (through the working EMS) and is apparently supplying power, since the microwave is working and I can engage the A/C.

As Alice exclaimed "Curiouser and curiouser!"

Denny16

CharlieRN, you are reading the battery in its connected on condition, and the shunt monitor is showing the current state of the battery under a load, not its actual charge level.  To get a good charge level reading, you need to shut off the battery switch, let the battery rest for an hour or so, then take a reading, you will get is actual charge level.  With the battery connected to the power converter, you are measuring the voltage coming from both the converter and battery, in relation to any loads on the DC power circuit.

Also, the percentage remains of the battery charge display, is dependent on how,you set up the monitor in its configuration menus.
cheers

MarkAl

To your original question the only large draw if everything is functional is the refrigerator and maybe if the main interior lights are ON but I'm betting these are OFF. If ON and very low solar it would easily discharge the battery over a week. Otherwise there's a electrical problem and the fuses and each circuit should be checked.  To the 2nd issue of the charging. The batteries may WANT a large charge when fully discharged but the converter when connected to shore power is protected and limited in output and the solar radiation limits output to what's available from sun and the specific controller (10 or 15 amps usually) so it could easily take quite awhile to fully recharge assuming the BMS is re-activated. To quickly recharge, a high output re-charger would be needed.

Sharon_is_SAM

Not that it should draw much, but the Victron BMS does not account for the draw of the shunt/monitor itself.

SLJ

CharlieRN said:

SLJ said:

USB ports and the two overhead LEDs are parasitic draws.

ontheroad said:

Is your outside step out..it has a lovely light that stays on unless the step is pushed in...we have a clamp that we use to turn off the light...when set up we prefer a solar light near the step..

Regarding @SLJ 's comment, the only o/h LED light in my 320 is a circular lamp. It's switched, so should not be drawing any current.

Regarding the outside step, it is in the retracted position (I think I measure it as drawing about 0.3 amps when open). I intend to add a a switch so that the step can be extended but not lighted, though haven't  been able to do that yet. Regardless, it's retracted with no light, so not part of the drain right now.

Even more puzzling is what happened last night. When I checked the SmartShunt just after sunset, it showed battery capacity at 86%. This morning, it read 80%. (the battery switch is in the on position). That would not be surprising except that it is connected to shore power. The converter is definitely connected (through the working EMS) and is apparently supplying power, since the microwave is working and I can engage the A/C.

As Alice exclaimed "Curiouser and curiouser!"

If you have a newer 320 the two round overhead lights are parasitic draws. The switch turns off the main LEDs but leaves the lighted switch on.