12 volt battery charging.

[Sloucher]

I've not received my ZS LR EV (and don't expect to for a loooong time yet, it was only ordered in April), but after reading all the 12v battery woes on here, I want to plan ahead.
I currently keep a smart charger connected to my existing ICE car to keep the battery in good condition, can I safely do the same with the EV without disconnecting the battery?
What about using a V2L cable to power the said smart charger whilst the car is not being used, is that even feasible?

 

[AK OK]

I've not received my ZS LR EV (and don't expect to for a loooong time yet, it was only ordered in April), but after reading all the 12v battery woes on here, I want to plan ahead.
I currently keep a smart charger connected to my existing ICE car to keep the battery in good condition, can I safely do the same with the EV without disconnecting the battery?
What about using a V2L cable to power the said smart charger whilst the car is not being used, is that even feasible?

Are you sure you need a car?

 

[Jomarkh]

That's a great question.
Can you use the HV battery to charge the 12v battery?
I think on the car you have on order if the 12v drops below a certain voltage the HV battery tops it up anyway...

 

[Sloucher]

Are you sure you need a car?

Yup!
The reason my current car is not being used and hence hooked up to a smart charger is that I'm waiting for an eye operation (due in a couple of weeks, thank goodness) to restore decent vision again. I don't particularly enjoy driving with one eye, and yes I did try....once!!
I'm having to rely on friends, relatives and public transport in the interim!

@Jomarkh that's what I thought as well, but it seems some folks are having problems with the battery discharging whilst the car is switched off.

 

[AK OK]

Yup!
The reason my current car is not being used and hence hooked up to a smart charger is that I'm waiting for an eye operation (due in a couple of weeks, thank goodness) to restore decent vision again. I don't particularly enjoy driving with one eye, and yes I did try....once!!
I'm having to rely on friends, relatives and public transport in the interim!

Oh right?

@Jomarkh that's what I thought as well, but it seems some folks are having problems with the battery discharging whilst the car is switched off.

By the time you get it you'll most likely be back in the saddle eyes wise? Even if not, all you'd have to do would be put it in ready mode for a while every few days & it will charge the 12v battery itself.
I read that mk2s can charge the 12v automagically even without human intervention ?

 

[Coulomb]

What about using a V2L cable to power the said smart charger whilst the car is not being used, is that even feasible?

Not feasible. No V2L when car is idle.

 

[Spinynorman]

I need to know if you can use a separate mainenance charger connected to the 12v too.

I’ve heard so many conflicting pieces of advice - yes you can/ no you can’t ‘ yes but remove the cables to the battery first - if you do that, how do you lock the car? How do you open it, without using the key? No battery = no alarm???
I know standard charging on a Mk1, should also charge the 12v and that putting the car into ready mode also charges the 12v from the main battery, but if you don’t use your car for a week or so, how long do you have to keep your foot on the brake to top it up?
Confused…?

 

[N2STY]

You don't need to keep foot down to charge the battery once it's in ready mode it will just change the same when your driving around possibly you're overthinking this?

 

[BrianG]

But you can charge the 12 v battery with a smart charger, one cable to the positive side on the battery the other to the body earth point. The issue with the batteries is that they are not heavy duty, they don’t need to be so they can be inadvertently run flat.

 

[Kithmo]

But you can charge the 12 v battery with a smart charger, one cable to the positive side on the battery the other to the body earth point. The issue with the batteries is that they are not heavy duty, they don’t need to be so they can be inadvertently run flat.

The ZS 12v battery is pretty substantial at 63Ah and CCA 570A at -18C.
The problem is not the battery but the relatively low output of the charging system compared to an alternator, it takes longer to recover when it's run down.

I need to know if you can use a separate mainenance charger connected to the 12v too.

I’ve heard so many conflicting pieces of advice - yes you can/ no you can’t ‘ yes but remove the cables to the battery first - if you do that, how do you lock the car? How do you open it, without using the key? No battery = no alarm???

No need to disconnect the battery if using a smart charger.
I have a CTek conditioner/charger and what's called a comfort connection, a cable with a plug on that's permanently connected to the 12v. When I want to charge it I just plug the CTek into the cable.

 

[Coulomb]

The problem is not the battery but the relatively low output of the charging system compared to an alternator, it takes longer to recover when it's run down

The DC-DC is quite powerful, much more so than most alternators, but the target voltage isn't high enough for enough time. In other words, it's got the grunt, but doesn't make the effort. So this is another thing that could be fixed by minor tweaks in the firmware, but it seems it hasn't improved much since the first Mk1.

 

[N2STY]

The DC-DC is quite powerful, much more so than most alternators, but the target voltage isn't high enough for enough time. In other words, it's got the grunt, but doesn't make the effort. So this is another thing that could be fixed by minor tweaks in the firmware, but it seems it hasn't improved much since the first Mk1.

I wonder if it's the opposite it a bit to good and its cook in the battery so it loses capacity?

 

[Coulomb]

I wonder if it's the opposite: it's a bit too good and it cooks the battery so that it loses capacity?

That's certainly possible, but I suspect it's just not charged at high battery voltage for enough time.

Charging lead acid batteries has been done for well over a hundred years, it's not like this aspect of EVs is a bleeding edge technology!

 

[Lovemyev]

No need to disconnect the battery if using a smart charger.
I have a CTek conditioner/charger and what's called a comfort connection, a cable with a plug on that's permanently connected to the 12v. When I want to charge it I just plug the CTek into the cable

I have CTEK Smart unit with the quick connect facility, brilliant !.
You are up and charging with 2 minutes.
No crocodile ? clips to connect, which can slip off.

 

[Susanna]

I have CTEK Smart unit with the quick connect facility, brilliant !.
You are up and charging with 2 minutes.
No crocodile ? clips to connect, which can slip off.

This sounds like something I might buy. Do you get instructions on how to fit the leads to the battery? I have never done anything ‘under the bonnet’ (of any car), so would need a thorough tutorial!!

Edited to say I just watched the installation process on YT.

 

[Lovemyev]

This sounds like something I might buy. Do you get instructions on how to fit the leads to the battery? I have never done anything ‘under the bonnet’ (of any car), so would need a thorough tutorial!!

Edited to say I just watched the installation process on YT.

They it’s pretty straight forward, you bolt the red positive eyelet to the main battery terminal and the black negative eyelet to a main ground terminal on the body shell.
You can just bolt the black negative eyelet direct to the negative terminal of the battery, but they recommend using a ground post on the body shell.
On the ZS EV ( Both Gen 1 & 2 ) there is a main ground terminal located just behind the rear of the 12 volt battery.
If I remember correctly, it is a 10mm nut that can be removed to fit the eyelet then reffited and tighten back up.
But you can use the main negative terminal on the battery if you wish.
Or just use the supplied crocodile clamp supplied with the unit.

 

[Sloucher]

Good news you can use a CTEK smart charger as that's the very one I have and was initially enquiring about.
I'm currently (see what I did there?) using it on my ICE Alfa whilst it's laid up until I have an eye operation, and the charger keeps the battery in optimum condition.
As has been mentioned, the quick connect leads are very convenient to use, just make sure to clean the bullet type connectors from time to time as they do have a tendency to corrode and interfere with the charger function (guess how I know?!)