Battery Self Discharge Rate

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smithy2167
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Battery Self Discharge Rate

Post by smithy2167 »

I'll be leaving the Zoe (2019 model) unattended for periods of possibly 2-3 months.
- Does anyone have estimates for the discharge rate of the battery when the car is sitting idle?
- Should I leave the charger connected?
Dave
2019 Jaguar IPace
2019 Renault Zoe
antiscab
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Re: Battery Self Discharge Rate

Post by antiscab »

The big battery won't go flat in that time, but the 12v one might.

That's the one I would charge
Matt
2017 Renault zoe - 25'000km
2007 vectrix - 156'000km
1998 prius - needs Batt
1999 Prius - needs batt
2000 prius - has 200 x headway 38120 cells
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smithy2167
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Re: Battery Self Discharge Rate

Post by smithy2167 »

So I assume then that the 12V battery is only charged from the traction battery when the vehicle is actually running?

Given how critical the 12V battery seems to be to both operation and charging of the vehicle, and given that there must already be a (12V) battery DC-DC charger in the vehicle, it wouldn't appear to be a big step for the manufacturer to monitor the SOC of the 12V battery and kick in the charger if needed. But, it would seem not.

The whole concept of needing a 12V lead-acid battery, with a 3 year life, in an EV loaded with lithium batteries needs a rethink.
Dave
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2019 Renault Zoe
antiscab
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Re: Battery Self Discharge Rate

Post by antiscab »

the issue with keeping the 12v battery charged tends to have been whilst the car is off, is making sure the big battery doesn't get run down to 0v.
not impossible, but certainly challenging.
Matt
2017 Renault zoe - 25'000km
2007 vectrix - 156'000km
1998 prius - needs Batt
1999 Prius - needs batt
2000 prius - has 200 x headway 38120 cells
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smithy2167
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Re: Battery Self Discharge Rate

Post by smithy2167 »

Certainly, the car needs to avoid discharging the traction battery completely. But the 12V battery looks like about 50Ah = 600W so a full traction battery could fully charge it 70 times.

Interestingly, I just Googled looking for the 12V battery capacity and stumbled upon this on the Renault site:
https://easyelectriclife.groupe.renault ... d-of-time/

Their chief battery engineer says: “The self-discharge of a battery in Renault ZOE, in other words the loss of charge when the car is parked but not plugged in, is imperceptible over time.”

and "The best option is to charge your battery to no more than 50% before leaving your car parked for an extended period of time."

and finally " ... it is best not to leave the battery completely empty either, so that it can regularly recharge the small 12V battery that powers the car’s various accessories."

So, it would appear that it does keep the 12V battery charged.
Dave
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Re: Battery Self Discharge Rate

Post by doggy »

I have left our Zoe for 6 weeks without problem.

One "secret" tip is to lock the car with the card-key when you are leaving it. This reduces the current drain as it is not constantly "looking" for the card key.

Totally agree to leave it at 50%. That is common for all Lithium batteries.

The good news is that when I left mine for 6 weeks (travelling overseas), the SOC only went down 1% over that time. I did not check the 12V battery but all worked well upon return.

So, compared with Teslas which have a fair bit of software constantly running, leading to Phantom Drain, Zoe is excellent.

Cheers,
Dave
Renault Zoe ZE40, 2017
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