Car will be unused for an extended period, Zappi advice required

[Drew57]

I'm checking for advice from Zappi Charger owners as shortly my car will be plugged in, unused & unmonitored for at least eight weeks by which time temperatures could get very low.

At the moment I plan on charging to 90% then reducing the SOC slider to 50% & plugging in on the drive. I will turn off all charge schedules on the car and rely on the Zappi & although I may check in on the car every few weeks via the app, there is nothing else likely to poll or wake it up.

Although I should expect SOC to remain above 50% for the duration I want to be certain something unexpected doesn't occur. In every normal circumstance I use Eco+ for scheduled charging so would it be best to....

a) Leave the Zappi on Eco+ with a scheduled Go Faster charge 02.30-06.30 7 days a week which will presumably kick in if the SOC drops below 50%

or

b) Leave the Zappi on Fast mode without any schedules so if SOC drops below 50% it should charge immediately.

Other people, builders, tradesmen and family will be at the house many days & nights but none will be interfering with the car or have knowledge about car charging.

Would options a, b or something else be the best?

(& if I set an Eco+ timer for every day would the Zappi wake the car at 02.30 to check? whereas the Fast option will do nothing until below 50%)

 

[Dilly]

Where you’ll get a problem is if the charge completes. I’m not certain but you may need to unplug to reset it (which of course you can’t.
using the myenergi app remotely, can you not leave the SoC a bit low and just top up from time to time with a short scheduled boost, building up for your return.

 

[Drew57]

Where you’ll get a problem is if the charge completes. I’m not certain but you may need to unplug to reset it (which of course you can’t.
using the myenergi app remotely, can you not leave the SoC a bit low and just top up from time to time with a short scheduled boost, building up for your return.

Would that happen but it's a good point?

I think I'll try setting two charges for one night later this week when it's expected to be much colder, starting with a target SOC only 1% above the existing level, one at 02.30, the other 06,15 both for 15 mins. Hopefully the cold will drain more than 1% in between & I can see if it restarts.

My concern with leaving a lower SOC is that if a charge & subsequent ones fail then there won't be much room for error. 90 % should give lots of leeway and I have left the car previously in a car park for 12 October nights with only a total 2% loss.

 

[Cardo]

I would stick the Zappi on fast, that way if the car asks for more charge then the Zappi should provide it, even if it previously deemed the charge complete. Fast mode should provide whatever power the car asks for. Should.

 

[MrT3]

Hopefully the cold will drain more than 1% in between & I can see if it restarts.

Leave sentry mode on over night, that will ensure your charge drops enough. Just make sure the first charge is long enough to get to your target level in the first place taking into account the loss of charge sentry will cause.

 

[Drew57]

Some good suggestions, thanks.

Another thought is to leave the car settings as I suggested & the Zappi on Fast mode but set an 02.30 Scheduled charge in the Tesla app. I've been using something similar with the granny charger while staying at my Fathers house for the past two nights and it is working just fine. I quite like this idea because the Zappi will not need to intervene at any point & should just act as a dumb power supply (as the UMC is doing at the moment until the scheduled start time).

I've got a week before I go so can try a few things out.

EDIT: it just occurred to me that I propose to trust Tesla more than the ever reliable Myenergi.... a scary thought indeed

 

[Mr Miserable]

If you behave yourself they may release you earlier!

 

[Adopado]

I've got a week before I go so can try a few things out.

EDIT: it just occurred to me that I propose to trust Tesla more than the ever reliable Myenergi.... a scary thought indeed View attachment 735216

I have had the Zappi fall over a few times since I've had it (September 2019). In fact I had to have a Hub replaced AND the Zappi main unit. I have also had it requiring a restart* due to reported voltage fluctuations ... apparently fixed with a software up date. I have never had the car fail when set for a timed start (using the Zappi in "fast" i.e. dumb mode).

*that would require physical intervention whether using Zappi schedule or car starting time method becasue it would be non functional until the restart.

 

[NISFAN]

I suspect it’s not the main battery you should be focussing on, after all, one charge in the middle of your absence will top back up enough to cover the phantom drain.
The small battery will probably need a charge half way at the least, if not more often.

 

[Adopado]

I suspect it’s not the main battery you should be focussing on, after all, one charge in the middle of your absence will top back up enough to cover the phantom drain.
The small battery will probably need a charge half way at the least, if not more often.

The 12v battery is charged from the main battery so it shouldn't be an issue so long as it isn't allowed to drop to low percentages.

 

[Fursty Ferret]

Just leave it plugged in and the charge level set to 80%. The battery can look after itself.

 

[Drew57]

Just leave it plugged in and the charge level set to 80%. The battery can look after itself.

That's what I plan to do but I need to be confident which option is going to be the most reliable. Zappi's can sometimes lock up for no obvious reason - It's happened with mine and apparently @Adopado's too.

 

[Fursty Ferret]

Leave the Zappi on Fast mode without any schedules so if SOC drops below 50% it should charge immediately.

Even if it does lock up in this mode the car will remain supplied. Why would you set the SOC to 50% and risk damaging the battery in the long-term, though?

 

[Drew57]

Even if it does lock up in this mode the car will remain supplied. Why would you set the SOC to 50% and risk damaging the battery in the long-term, though?

Not sure you read my first post?

....I will charge the car to 90% before I leave & once that's complete reduce the slider to 50% so if it falls below that level it will start to charge again.

I don't see the point on leaving the slider at 80% as the car may be charging frequently from some point whereas at 50% it's entirely possible it won't need to do so at all (depending on temperature).

 

[Drew57]

From trial & error I've come to the conclusion that using the Zappi as a dumb charger & scheduling a charge in the Tesla app is likely to be the most reliable.
See recent post here

If the car is plugged in and the target SOC is lower than the existing SOC then it will start charging at 2.30 on a later night once SOC drops below the target level. Although I haven't been able to test if this happens on subsequent nights, presumably the same will occur until the car is eventually unplugged.

 

[HenryT]

Not sure you read my first post?

....I will charge the car to 90% before I leave & once that's complete reduce the slider to 50% so if it falls below that level it will start to charge again.

I don't see the point on leaving the slider at 80% as the car may be charging frequently from some point whereas at 50% it's entirely possible it won't need to do so at all (depending on temperature).

Better for the car to charge frequently if you believe what Tesla say. Nothing to be gained by letting it run down to 50%.

See here for more info.

​

 

[Drew57]

I do have a plan B - next door neighbour used to have a Model 3. He also has a Zappi so if worst comes to the worst I will call him to unplug & reset my charger. He's happy to do that.

(his new M3 P is due for delivery on Friday)

 

[Nujec]

Haven't had a problem with Zappi v2 failing to work but I've only had it for 5 weeks and I am on the latest Zappi firmware as at start of December 2021.

Great that you have a plan B with your neighbour.

I have been using my Tesla 2021 M3 with Zappi in ECO+ with timed boost without using M3 scheduled charging.

I noticed on the Zappi app that the M3 draws some chargepoint power every hour after charging is complete, perhaps to power the car turning on to perform system checks and/or top up the battery if required. If Zappi Charge settings/Preconditioning is turned on then the M3 will get power from the Zappi to do this check outside the timed boost window. If Preconditioning is off then the M3 will be be refused charge for the first hourly check outside the timed boost window, generate an interrupted charge warning in the Tesla app then give up asking for chargepoint power until next plugged in. I assume the M3 then does hourly checks using battery power only. AFAICT you can only change Zappi preconditioning on the Zappi screen, not in the Zappi app. I'm not sure if the M3 does this hourly check using chargepoint power outside the M3 scheduled charge times if using M3 scheduled charging.

Now the weather is colder and I'm getting cold weather warnings I've switched to using Zappi in ECO mode with timed boost and turned on Zappi preconditioning so that the M3 can get most of its charge at the cheapest times when the temperatures are coldest then trickle top up the battery at 1.3kW the rest of the day while plugged in keeping the battery a bit warmer overall for long term battery health at the cost of using a small amount of electricity outside the cheapest rates. I'm assuming here that regular slow charging is the least stressful way to top up the battery.

I also charge to 60% or 65% on nights when I know we'll be doing very little mileage the next day and aim to end the day not much lower than 50%. For non LFP batteries that there's only a minor gain in long term battery health charging to 60% rather than 80% but I'm hoping to keep this car many years and tweaking charging habits over thousands of low mileage days may add up to a significant lifetime difference. I haven't seen anything that says charging to 80% is definitely better for the battery than charging to 50-60% but there is quite a lot of research on Lithium ion batteries to suggest keeping the charge in a small interval around 50% results in the very lowest degradation.

 

[Drew57]

Thanks @Nujec I wasn't aware the Zappi had a pre-conditioning option. I use the app to set charges & the only setting change on the charger itself was for a security PIN.

I haven't noticed my car drawing power after a charge is complete & don't knowingly use preconditioning settings apart from occasionally prior to Supercharging or pre-heating climate on a cold morning.

Fortunately I haven't needed my Neighbour to check anything & on Tuesday my Daughter showed me the Zappi screen via FaceTime & everything looked normal (about 6 weeks plugged in now). As far as I know the car is still fast asleep.... I'll find out in a couple of weeks!

By the way I only use Eco+ for timed boost. After trying Eco and failing, Tech Darren @ Myenergi told me that it wouldn't work so always use +

 

[Nujec]

Thanks @Nujec I wasn't aware the Zappi had a pre-conditioning option. I use the app to set charges & the only setting change on the charger itself was for a security PIN.

I haven't noticed my car drawing power after a charge is complete & don't knowingly use preconditioning settings apart from occasionally prior to Supercharging or pre-heating climate on a cold morning.

Fortunately I haven't needed my Neighbour to check anything & on Tuesday my Daughter showed me the Zappi screen via FaceTime & everything looked normal (about 6 weeks plugged in now). As far as I know the car is still fast asleep.... I'll find out in a couple of weeks!

By the way I only use Eco+ for timed boost. After trying Eco and failing, Tech Darren @ Myenergi told me that it wouldn't work so always use +

I didn't have the preconditioning option with the factory installed Zappi v2 firmware. It only appeared when I did a firmware update - instructions for updating here : Updating your firmware on myenergi devices | myenergi UK . It's handy to have the option for battery top-ups and allowing the M3 to do scheduled preconditioning and cabin heating with chargepoint power rather than depleting the battery and adding to average depth of discharge over the years.

I'll keep an eye out for timed boost problems with ECO mode, thanks for the warning.