Low Battery Warning; Charge Immediately

[emachine]

Hello, I own a 1.5 Roadster was purchased used, and was not in the best of shape, and the intention was for it to be an evening and weekend project. Needless to say that was several years ago. That said, it has been dutifully hanging out in Storage Charge mode for several years with some very light driving (once every other month or so).

We had some power outages this past weekend (and I was out of town traveling for work), and during that time I have started getting the following seemly serious Warnings/Errors on the Video Display:

Power failure Service required (259)
Internal communications error Service Required (1096)
Low Power System Service required (1416)
Battery error Power Reduced (50)
Internal communications error Service required (885)

Vbat shows 248v (Ugh)

Shows 257 mi ideal range (Seems incorrect).

Then Low Battery Warning Charge Immediately is displayed.

I am worried that even though the vehicle shows that the battery is full (which I pretty much don’t believe as I don’t see the capacity drop) it is losing charge, and will brick. I did try pulling the ESS Service Disconnect hoping that would reset/resynchronize, but there seems to be no change in behaviour. When I connect the charge plug the Video Display says Preparing to Charge indefinitely, and when I disconnect the charge plug and shut the charge port door, the car instantly shuts down.

Looking for any guidance you folks can provide. Is there a way to force a charge?

Thanks,
--Eric

 

[dhrivnak]

Charge fully in standard mode as the battery WILL become unbalanced over time in storage mode. Only when battery is above 85% will the balancing happen if badly unbalanced you may need to range charge and let it sit a few days.

 

[emachine]

What I'm having a hard time reconciling is the Warning/Error that pops up that says Battery Low; Charge Immediately against the 257 mi ideal range. In diagnostics mode the Vbat shows approximately 249v which seems too low for a fully charged battery pack....

When I open the port door and select charge standard, the car tells me: Preparing to Charge, the port door color is Blue, the battery heating/cooling comes on for a few minutes, and then it stops (suspect because the range shows 257).

Anyone know if its possible for the display to show the incorrect battery state versus the charge that is actually present?

--Eric

 

[emachine]

This seems similar to what happened to me as mine went wonky during power outage while charging:

Communication Error on my 2.0?

Only opening and closing the charge port door didn't seem to clean it up. Its sitting in the garage now with the ESS Service Disconnect pulled as I don't know what the state of charge is. While I'm asking the above questions, how do you do a full reset of a 1.5? Is it just pulling the disconnect? What is the most reliable indicator of state of charge?

I was going to reset the plugs for the VMS while I have the disconnect pulled, is there any others that I should look at?

I have an email out to the Service Center but no response so far.

--Eric

 

[wiztecy]

What's your SOC? How long has the Roadster been sitting without doing a full range mode or 3-5 standard mode charges that allow it to balance out properly? Ideal miles doesn't mean much, the VDS can read the last time it did a reading on the value after its last calculation and a drive & charge / possibly hard VMS reboot should refresh that. I've seen Roadsters with dead batteries display fake mileage on the screen, such as 50 ideal miles or so. As dhrivnak mentioned above, another owner received the battery low message and dhrivnak suggested the same methodology, the battery balanced and they were up and running as normal.

 

[emachine]

What's your SOC? How long has the Roadster been sitting without doing a full range mode or 3-5 standard mode charges that allow it to balance out properly? Ideal miles doesn't mean much, the VDS can read the last time it did a reading on the value after its last calculation and a drive & charge / possibly hard VMS reboot should refresh that. I've seen Roadsters with dead batteries display fake mileage on the screen, such as 50 ideal miles or so. As dhrivnak mentioned above, another owner received the battery low message and dhrivnak suggested the same methodology, the battery balanced and they were up and running as normal.

Hi wiztecy, thanks for the response. Its probably been at least six months since doing a full range mode charge.

I think thats the issue, I don't know for sure what the SOC is. The display shows 100% charged. But the low battery warning keeps popping up. It could be that this warning happened before the power outage and then when it came back on the Roadster did a full charge. Are those warnings persistent? Is there another place to check the battery voltage in case what the VDS is displaying is stale? Something in the Diagnostics menus? What I'm worried about is the display showing 100% charged but the battery actually at a very low SOC. Am I being paranoid about the warnings (I don't like seeing the ones with the red outlines )? I am away from the vehicle for 4 days this week, and then I am traveling for work for almost three weeks and pretty worried that I am going to have a brick while I'm away....

As far as a hard VMS reboot, pulling the ESS service disconnect should do that correct? Its sitting now with the ESS service disconnect pulled because I am paranoid about the SOC. I also just re-seated the VMS connectors for when re-plug the service disconnect.

Thanks for your help,
--Eric

 

[ChadS]

Hi Eric,

I doubt I can help much, but here are a couple of tidbits:

1. One way to reset the car is to open and close the charge port door 6 times. Though I would imagine ESS disconnect would do that and more.
2. It is possible for the VDS display of charge level to be off; I've seen it happen - in fact I got a communications error (the problem was communicating the battery status to the display). So after a reset hopefully you will get better info.
3. Do you have the car plugged in to 120V or 240V? I was once told that frequent, long-term use of 120V may make CAC calculations drift lower - although it was unclear if that is for every Roadster, or just for the first couple hundred 2.0's (mine is one of those, and I had a problem about 2 years ago after charging on 120V for about 18 months). I also seem to recall them saying it would make impedance problem as I mention in the next item more likely, but can't find that written anywhere so maybe I misremembered.
4. My problem (according to Tesla - more info HERE) was a sensor lead rivet developed impedance where it connected to the collector plate. This causes a voltage drop; in fact it went so far the BMS assumed the car was overcharged, and so it would not let me start or charge the car.

Good luck,
Chad

 

[spaceballs]

I've PM you. I'm sure I can help you out as I've worked on my ESS(s) before, I'm local too!

 

[AB4EJ]

What I'm having a hard time reconciling is the Warning/Error that pops up that says Battery Low; Charge Immediately against the 257 mi ideal range. In diagnostics mode the Vbat shows approximately 249v which seems too low for a fully charged battery pack....

When I open the port door and select charge standard, the car tells me: Preparing to Charge, the port door color is Blue, the battery heating/cooling comes on for a few minutes, and then it stops (suspect because the range shows 257).

Anyone know if its possible for the display to show the incorrect battery state versus the charge that is actually present?

--Eric

Could this be because the 12v battery is nearly dead? I know that the Toyota hybrid system goes bonkers & shows all kinds of crazy stuff when the small 12v battery is going out.

 

[slcasner]

Could this be because the 12v battery is nearly dead?

The 1.5 doesn't have a 12V battery. The 12V is supplied only from the main traction battery through a DC-DC converter.

 

[ML Auto]

At 248V I'm afraid the ESS is already a brick. You need to look at the lowest brick voltage-below 3 volts is a problem. I don't think you will get it to charge using normal means. 3 volts times 99 bricks = 297 Volts. You are well below that. The range was probably the last time it was driven. Once the ESS shuts down the range stays put. I'm not even sure if you will be able to read the lowest brick voltage. The 1.5 uses two sheets for the 12v for the VDS power, which tells me you have some power in The ESS, which is a good sign. You will probably have to disassemble the ESS and recharge the bricks ASAP to avoid a very costly expense. Talk to spaceballs, he can let you know what you need to do. Do it fast-you probably only have a couple of days. If the bricks are evenly discharged (unlikely) you would be at 2.5 volts per brick- thats about where you will have irreparable cell damage.

 

[wiztecy]

+1 with what MAUTO said and you're in luck and with good hands for that spaceballs is close by. I also felt that 248 volts was extremely low, if you read that from diags, then its where it is unfortunately and its going to need some help.

If you have access to diags, goto the page that displays the low, min, avg voltages for the bricks. If you can take a pic of that page that would help. Also in diags it'll show what your SOC is, a pic of that would be good. Lastly, dump a fresh set of logs. I'm sure this will greatly help spaceballs in helping you as well as others like MAUTO to add their expertise and experience. It will let them know which brick & sheets that are the worse in the pack and give better insight into the issue.

 

[spaceballs]

You will probably have to disassemble the ESS and recharge the bricks ASAP to avoid a very costly expense.

My emergency charging tool don't require to drop the pack luckily so one can start to recharge asap if you get into a state where you can't charge normally.

 

[ML Auto]

My emergency charging tool don't require to drop the pack luckily so one can start to recharge asap if you get into a state where you can't charge normally.

I agree, but I doubt you can charge all the bricks fast enough to prevent further damage. I don't know how many amps you charge thru those tiny riveted wires, but I doubt you can do one more than one brick a day-thats over three months. Now if you have 11 chargers working from 11 different power sources, then you can do it in only 9 days. Once the sheets are out and separated, you can parallel them and do them all at once using a 24v charger.

 

[spaceballs]

I agree, but I doubt you can charge all the bricks fast enough to prevent further damage. ...

0.25A at 250V is >62 watts it's more than enough. Remember only need to get the battery out of the dangerzone then have normal on-board charger do the rest.

Also I do have > 11 boards

I still haven't heard back from emachine.

 

[ML Auto]

0.25A at 250V is >62 watts it's more than enough. Remember only need to get the battery out of the dangerzone then have normal on-board charger do the rest.

Also I do have > 11 boards

I still haven't heard back from emachine.

250V? Are you charging the whole pack at once? I would think you would need at least 350V to do that. I remember it took half a day charging at 8 amps to bring the whole sheet from under 2.5V to 3.5. Still not sure how you will isolate the sheets if you intend to use 11 boards at once.

 

[spaceballs]

250V? Are you charging the whole pack at once? I would think you would need at least 350V to do that. I remember it took half a day charging at 8 amps to bring the whole sheet from under 2.5V to 3.5. Still not sure how you will isolate the sheets if you intend to use 11 boards at once.

I have two methods, one is with many isolated DC-DC converters that are current limited to each brick, the other whole pack constant current from 200v-400v.

 

[ElectricLove]

I know it is dangerous and only a skilled technician should do it but if emachines vehicle will go into drive mode (ie close the contactors in the ESS) he could open top of PEM and wire a 300-400VDC charger onto the DC input... Using EXTREME cautions of course! Then he could turn the car to the "on" position and look at the actual voltage with a DMM and charge the ESS at that time... Once its around 260VDC, I'd say shut the charger off then shut the car off and plug it in to see if the on-board charging will come back to life...

Anyways, like I said extremely dangerous due to working around exposed HV wiring, but it'd work... Otherwise spaceballs tool is a great choice!