Battery Tender / Trickle Chargers

theboots

Novice Member
Joined
Feb 8, 2025
Messages
3
Reaction score
2
Points
4
Location
Hornchurch
Driving
MG4 Trophy LR
Has anyone used a trickle charger when away for a while to keep the 12V battery topped up? I see there are solar ones with reverse protection which should do the job. I am thinking of a long trip away maybe 12 weeks duration and that's a bit long to keep my fingers crossed that it survives. And would it need to be connected directly to the battery which would be a faff or can we go via the 12V cigarette lighter socket.
 
The 12V socket is isolated via a fuse and switch/relay (i.e. it turns off a wee while after the car is locked), so I'd assume that there's no direct connection to the battery
 
The answer in No from here, but,,,, I've left mine for 7 weeks without any issue. Instead of setting up some elaborate for while away, I'd suggest having a jump start power bank ready, if and only if it turns out to be needed. Seems like a more sure thing solution.
 
I use a CTEK charger on my Morgan. I am thinking for the ZS EV to leave it connected to the Ohme Home Pro charge point & charge say 5% occaisionaly via the app whilst away
 
The answer in No from here, but,,,, I've left mine for 7 weeks without any issue. Instead of setting up some elaborate for while away, I'd suggest having a jump start power bank ready, if and only if it turns out to be needed. Seems like a more sure thing solution.
Yes, I have one of these in my car. Never had to use it on my car, but did use it to jump start someone else's EV with a low 12V battery.
 
I'd suggest having a jump start power bank ready, if and only if it turns out to be needed.
I have one but of course if you let the 12V battery drop too low that does knacker it.

I am thinking for the ZS EV to leave it connected to the Ohme Home Pro charge point & charge say 5% occaisionaly via the app whilst away
I have a Zappi, I guess that would mean starting with a lower battery %age say 40% and add 5% every week.
 
People have reported that the MG4 loses less than 1% charge when the car is left for a couple of weeks, also it appears the traction battery will keep the 12V battery topped up if it's at 50% or above.

Check the 12V battery terminals are tight, charge the car to 70% and over inflate the tyres to prevent flat spots. Don't worry if the iSmart app reports that it can't connect to the car as it will go into a deep sleep to conserve power and enjoy your trip.
 
I left mine for 5 weeks parked up while I was away on vacation in Feb/Mar. Left it at 75% and was still at 75% when I returned and just drove away just like it was used the day before.
 
People have reported that the MG4 loses less than 1% charge when the car is left for a couple of weeks, also it appears the traction battery will keep the 12V battery topped up if it's at 50% or above.

Okay if that's confirmed then no need to do anything special

I left mine for 5 weeks parked up while I was away on vacation in Feb/Mar. Left it at 75% and was still at 75% when I returned and just drove away just like it was used the day before.\

Hopefully that confirms what Ian says above that the traction battery does keep the 12v alive
 
You can monitor the 12v battery charge via the “Vehicle Status” feature of the iSmart mobile phone app. My car has been stood for several days. I checked it 3 days ago and it showed 12.2v. Today it shows 12.6v so must be getting topped up from the traction battery system.
 
HI check out my post on this very issue here:
With an update that I now use the |MG granny charger on a 16amp wifi plug switch (Sonoff S20 smart socket) so I have total control over remote charging, works a treat while I'm away.
 
Has anyone used a trickle charger when away for a while to keep the 12V battery topped up? I see there are solar ones with reverse protection which should do the job. I am thinking of a long trip away maybe 12 weeks duration and that's a bit long to keep my fingers crossed that it survives. And would it need to be connected directly to the battery which would be a faff or can we go via the 12V cigarette lighter socket.
I use one of these, it does the job very well.
Screenshot_2025-05-03-21-51-32-79_680d03679600f7af0b4c700c6b270fe7.webp
 
Has anyone used a trickle charger when away for a while to keep the 12V battery topped up? I see there are solar ones with reverse protection which should do the job. I am thinking of a long trip away maybe 12 weeks duration and that's a bit long to keep my fingers crossed that it survives. And would it need to be connected directly to the battery which would be a faff or can we go via the 12V cigarette lighter socket.
I have one that I purchased for 25 pounds it's marketed by the AA and I've used it on three different cars including my MG4. You simply connect it to a mains connection and then to the 12 volt battery and press the start button. It keeps the battery charged up and I have used it for a eight week holiday no problems.
 
People have reported that the MG4 loses less than 1% charge when the car is left for a couple of weeks, also it appears the traction battery will keep the 12V battery topped up if it's at 50% or above.
Is it still 50%? I always thought that was a bug that got fixed, but I might be wrong about that.

Does anyone have any evidence of 12V top-up below 50%? Given the relative capacities and the impact of a flat 12V battery, it should really always charge the 12V, even if the HV battery is at 1%.
 
Is it still 50%? I always thought that was a bug that got fixed, but I might be wrong about that.

Does anyone have any evidence of 12V top-up below 50%? Given the relative capacities and the impact of a flat 12V battery, it should really always charge the 12V, even if the HV battery is at 1%.
I'm inclined to agree with you, but you could argue if the 12V usage has worked its way through the remaining traction battery, then something is wrong such as a dash cam left on, or I believe there is a radio fault which will drain the battery.

In that case having enough remaining to allow a jump start and drive to a charger may be preferable.
 

Are you enjoying your MG4?

  • Yes

    Votes: 952 77.6%
  • I'm in the middle

    Votes: 183 14.9%
  • No

    Votes: 92 7.5%
Support us by becoming a Premium Member

Latest MG EVs video

MG ZS EV Retrospective & First Look at the MGS5 EV | Live Q&A with Owners & MGEVs Panel
Subscribe to our YouTube channel
Back
Top Bottom