Ford Fiesta - Dead battery - jump start or buy new battery? - clappedout

If you end up with a dead (not flat?) battery as a result of not starting and using the car for 5 months, is it worth getting it jump started or just replace with a new battery?

I assume that if you jump started, you'd have to either leave it charging from the source / car booster battery? Or have to drive the car for more than an hour to recharge the battery. I also assume that the old battery may not even hold the charge after recharging?

What would you do?

Edited by clappedout on 08/09/2020 at 15:20

Ford Fiesta - Dead battery - jump start or buy new battery? - madf

Borrow a battery charger and recharge it

Ford Fiesta - Dead battery - jump start or buy new battery? - elekie&a/c doctor
The battery is toast . Replace it . Modern batteries don’t like being left in a discharged condition for long periods.
Ford Fiesta - Dead battery - jump start or buy new battery? - Andrew-T
The battery is toast . Replace it . Modern batteries don’t like being left in a discharged condition for long periods.

I you feel the cost of a new battery is not insignificant, find out whether the old one can be successfully recharged before ditching it :-)

Ford Fiesta - Dead battery - jump start or buy new battery? - gordonbennet

It may or may not accept a charge, preferably charge it via a decent proper battery charger.

If you decide to jump start it and let it tickover for an hour or three instead, put the sidelights or similar on so the alternator has a load to work against or it may not charage even if you left it ticking over all day...seen this happen in car compounds.

If it won't accept and hold a charge it's ruined, as said modern batteries will not tolerate being left fully drained for long before they are kaput.

Ford Fiesta - Dead battery - jump start or buy new battery? - edlithgow

If it won't accept and hold a charge it's ruined, as said modern batteries will not tolerate being left fully drained for long before they are kaput.

Pre-modern batteries didn'r like it much either, IIRC

Are modern batteries any more vulnerable in this respect? I'd have thought the base technology was pretty much unchanged.

You might have to trick a smart charger into charging a dead flat battery, by appjying 12V from another source to it, aor using a stupid charger, which will actually work.

I' wouldn't buy a new battery without being sure I needed one, OR as an emergency measure.

After my recent charging failure, my Taiwanese GF insisted on getting a mechanic to ride 100 m and administer a jump start, despite my insistence that it was possibly risky and certainly a waste of time and money.

(I'm not a "professional" so I don't know anything.)

The 300NT wasted would have been better put towards a new battery. I'd guess the old one has suffered some loss of capacity but I'd expect it to have some useful life remaining.

Edited by edlithgow on 09/09/2020 at 07:41

Ford Fiesta - Dead battery - jump start or buy new battery? - Railroad.

Car batteries are starter batteries, ie they are designed to pack a punch. They deliver a lot of power very quickly. They are not designed to be continuously discharged and recharged, unlike deep cycle batteries used on electric buggies and wheelchairs which are good for many charge cycles.

If a car battery is left in a discharged state over an extended period of time it's very unlikely it will recover. Try recharging it overnight with a battery charger and see if by the morning it holds charge. If it doesn't you'll have no choice but to replace it.

If it's a calcium type battery that's discharged you will need to boost charge it first for around an hour at 16v before it will take a charge at normal rate. If you have no means to do this then a new battery will be required.

Ford Fiesta - Dead battery - jump start or buy new battery? - clappedout

Hey everyone - thanks for your replies and thoughts on this matter.

I actually took the decision to replace my battery (before I started this thread) and glad I did judging by some comments. The old battery was getting on 3.5 to 4 years old.

Several of the mobile battery recovery services I spoke to gave me the impression that all they'll do is come out and literally jump-start and you're pretty much on your own after that. In that they're not going to spend time actually charging the battery - more likely to sell a new battery at above market rate.

My previous battery also had to be jump-started a couple of times, but I think the third / forth time, it didn't hold a charge properly.

Ford Fiesta - Dead battery - jump start or buy new battery? - clappedout

With a new battery, I assume that it'll be fine for me to not use the car often (every 2 weeks?).

How many miles should I put in on my next drive to stretch it's legs (so it recharges adequately and perhaps to recover the energy lost to starting it up)?

Edited by clappedout on 10/09/2020 at 23:58

Ford Fiesta - Dead battery - jump start or buy new battery? - edlithgow

I'd get a charger.

Lidl had reasonable looking ones, though availability of items like that is episodic.

The story is/was that in-car charging isn't very efficient and is usefully supplemented by occaisional use of an external charger. Dunno if this is up to date.

Check handbook, but in general on recentish cars I wouldnt use an external charger with the battery connected to the cars fragile electronic systems

Ford Fiesta - Dead battery - jump start or buy new battery? - gordonbennet

With a new battery, I assume that it'll be fine for me to not use the car often (every 2 weeks?).

How many miles should I put in on my next drive to stretch it's legs (so it recharges adequately and perhaps to recover the energy lost to starting it up)?

echoing Edlithgow i too would be inclined to buy a battery conditioner/charger, not using the car for a fortnight at a time then using it for one run might be ok in the summer, but come winter you'll be back to finding the thing discharged now and again when you need it.+

Ctek (other makes are available) smart chargers are designed to be used with the battery still connected, they come with a second set of terminals you can connect semi permanently.

Edited by gordonbennet on 11/09/2020 at 06:17

Ford Fiesta - Dead battery - jump start or buy new battery? - edlithgow

Ctek (other makes are available) smart chargers are designed to be used with the battery still connected, they come with a second set of terminals you can connect semi permanently.

MIGHT be OK, but I note the Honda Accord handbook says DONT.

They will be covering themselves and the owner against less sophisticated chargers than the CTEK, but OTOH I'd doubt CTEK will buy you a new car if it all goes horribly wrong.

Not really such a big deal to disconnect, even if you need another battery to keep the memories alive.

Ford Fiesta - Dead battery - jump start or buy new battery? - bolt

Ctek (other makes are available) smart chargers are designed to be used with the battery still connected, they come with a second set of terminals you can connect semi permanently.

MIGHT be OK, but I note the Honda Accord handbook says DONT.

They will be covering themselves and the owner against less sophisticated chargers than the CTEK, but OTOH I'd doubt CTEK will buy you a new car if it all goes horribly wrong.

Not really such a big deal to disconnect, even if you need another battery to keep the memories alive.

I would recommend this as I know others that use this and I am going to get one as well, it does actually work but plugs into diagnostics port so has direct connection to battery

https://smile.amazon.co.uk/AA-Essentials-AA1432-Battery-Charger/dp/B084M5ZL5L/ref=sr_1_3?dchild=1&keywords=aa+solar+car+charger&qid=1599813749&quartzVehicle=29-405&replacementKeywords=aa+solar+car&sr=8-3

it even charges in cloudy conditions which most do not.

Ford Fiesta - Dead battery - jump start or buy new battery? - Dorset123

Never disconnect a battery until the car shuts down completely this can take about 30 mins.

So turn off the car and open the bonnet and leave for about 30-40 mins then disconnect it.

Ford Fiesta - Dead battery - jump start or buy new battery? - jthan

What is the risk in disconnecting the battery straight after switching off? I've been doing that regularly on a 2014 Toyota (often only driven once a week or two) with no problem. Maybe I've just been lucky....?

 

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