If I get one of those Charge N Start kits, where you plug one end into your car's cigarette lighter  with the dead / dying battery and the other one into a car with a good battery's cigarette lighter then leave it for a while will it actually revive and charge the dead car battery?

 

Just wondering if it works if the dead/dying battery is an AGM battery and if the donor vehicle would have to have the same type of battery for it to work?

 

 

I know jump starter unit is probably better way to go, but i'm just interested to see if the charge n start is actually viable without causing issues to the car's electrics etc.

 

 

 

 

Looking at buying something like this : 

 

https://www.eurocarparts.com/p/streetwize-charge-and-go-car-to-car-starter-550993260?gclid=CjwKCAiA2L-dBhACEiwAu8Q9YH_Bxg2b39NrNujCJJeMJL3HTRUMT1PftZsSv3pyGRZ2Za1gO1jzsRoCAjQQAvD_BwE

don't think it would, because after so long, the canbus disables the power to it after so long. Also, you're limited to the rate of charge which can be provided into the circuit without causing a problem.

 

Using a proper battery conditioner is more recommended for the upkeep of batteries (it can charge and monitor the loss to work out the battery's health), if you think your battery is iffy, you'd be better off getting a replacement battery, rather than trying to fiddle out to get it back going again

Please note - I am not a mechanic or expert in anything.

 

Have a look at your Owner's Manual for advice on charging the battery and use an appropriate battery charger (+ maintainer).

 

Car batteries are probably the most oversold car part, RAC will sell you one if you've got a flat tyre! - BUT - many driver's now so use, abuse and neglect the car's battery and it is so important to modern cars that often the best remedy is just to replace even if it's premature for the battery.

 

I've revived a few "dead" car batteries but in the same way people tell you "the battery is good" when it isn't also a "dead" battery may be only dying and might be saverable.  Main problem is that it usually involves two things many people don't have one or both of - time and patience.

 

I put a charger maintainer on to the 18-month old AGM of my wife's 2015 Fabia Mk3 in December as a preventative measure, no signs (or warnings) what so ever that the battery was at all low from the car, it took 17 hours to fully recharge it (on the car, outside, at -3.5c at one point, 12v winter setting* -  *usually used at ambient +5c and below, but check specs).

 

I used the Ring RSC804 4 amp (that's all you need, up to 90Ah) Battery Charger & Maintainer, £23.49 - other chargers at other prices available.

 

Edited 1 January, 20233 yr by nta16
Please note - I am not a mechanic or expert in anything.

10 hours ago, tunedude said:

don't think it would, because after so long, the canbus disables the power to it after so long. Also, you're limited to the rate of charge which can be provided into the circuit without causing a problem.

 

The 12v accessory sockets in the Octavia are permanently live and directly connected to the battery via appropriate fuses. There are no relays or other switching electronics upstream so 'the canbus' cannot disable them.

 

 

The only limit to charging would be the fuse, on the wiring diagram I have the lowest is rated at 20a which is unlikely to cause issues for most chargers.

 

Please note - I am not a mechanic or expert in anything.

 

This type of thing is a get you out of trouble sort of device more for getting the car started than really charging the flat battery.  One way to kill a dying battery is to charge it too high and fast though this (pdf attached) Streetwise unit shows it's 10amp and "Typical charge time will take approximately 15 minutes, but no more than 45 minutes" - so not instant as some may want.

 

It seems a little bit Peter robbing Paul to me but it shows -

 

. "it will show the recipient vehicle’s battery capacity in %."

 

. "Please Note: If the display does not show any figure, the recipient vehicle’s battery is defined as dead, it cannot be recharged. Please call for the technician for new battery replacement."

  -  You would have to ask the manufacturer what they define as dead, some modern chargers give up on a battery far too easily where an old charger will be able to revive that battery.

 

. "the display will show the charging level going up.  Charge until it shows over 20%."

  -  20% 

 

. "Press the button “O” position again, when the display keeps over 20% means it’s ready to start"

- so when over 20% you can start but the battery will still need further charging and just driving the vehicle may not be enough to fully recharge the battery and a full recharge is needed otherwise you could soon be back to square one, repeatedly if the battery doesn't get a full recharge.

 

It's a quick partial fix and good to perhaps get you out of trouble but it's not something you should need to use often, or at all for yourself with just if required using an appropriate charger/maintainer as prevention/preparation perhaps two or three times a year if required (start of winter, end of winter, perhaps as winter tyres are fitted and removed if used and just after extreme hot summer weather spell).

 

https://www.streetwizeaccessories.com/files//85150602-97e8-408f-89b9-a7bb00f5afc6/SWCG Manual.pdf

SWCG Manual.pdf

 

Edited 3 January, 20233 yr by nta16
spelling