Feb 2020 I bought this model.  Battery wouldn't hold charge so dealer replaced battery with a Varta 000 915 105 CC (68Ah), so all was well.  Since then I have not managed any decent runs and battery doesn't get enough charge - sluggish start and certainly not enough to allow stop/start.

 

I did have a good charger but lent it in mid-December to my son, living 45 miles away.  Lockdown followed and he is shielding, so no way I can collect it legally.  All I have is a trickle charger with max output of 1.5 A, so by time I have opened car and connected charger have probably drawn enough current to pull battery down a bit.  Bit like pushing stones up hill, only for them to roll down again!

 

Being something of a dinosaur and grown up with batteries that usually lasted about two years and needed topping up regularly, I need advice on what sort of charger to but at a reasonable price.  Confused by all the ads which say 'Not suitable for stop/start'.

 

Having read car manual, only connect via + and ground on body, to avoid upsetting electronics.

 

Quite surprised by battery rating, as my 2001 Citroen C5 Diesel had a 110 Ah battery!

 

Any advice appreciated.

 

Ade

Ctek MXS5 is what I have and use. I bought a cigar adaptor so I can plug it into the boot cigar plug and run the lead into my garage with everything locked and secure and charge overnight. Works a treat... They work fine with all types of battery and worth their weight in gold. I don't do many miles so top up once every couple of weeks. 

I would have thought a 1.5a charger would be perfect to keep the battery topped up?

 

Obviously a 5a charger will charge it 3.333x quicker but given it's not a flat battery and you're looking to just top up, I'd try the 1.5a for a few days and see how it does.

Ctek MXs5 is a great piece of charging equipment, its very small and will easily fit under the bonnet, car can be locked and flying lead will fit out from under the bonnet. Not cheap but has as mentioned will do all stop start battery and also recondition it too.

 

Worth every penny. 

Im considering buying a new charger to replace my old fashioned heavy charger. Not that I need to charge at the moment, but having 3 cars (that are being used less) I know the day will come when I need it.

 

Two cars have standard batteries, and the Skoda a EFB / Stop Start.

 

Looked on Autoexpress, and ctek keeps getting mentioned on this site. I went to the ctek website though and got confused.

Options include: 

 

MXS 5.0

MXS  5.0 Test and Charge

CT5 Time to Go 

CT5 Start stop.

Sealey Autocharge650HF

RIng RSC612

Ring 

 

Do you need a different charger for start and stop? Some have a recond mode? Is there any advantage to charging the battery on this a every 6 months / years to make sure it is topped up? 

9 hours ago, Regulation12 said:

Feb 2020 I bought this model.  Battery wouldn't hold charge so dealer replaced battery with a Varta 000 915 105 CC (68Ah), so all was well.  Since then I have not managed any decent runs and battery doesn't get enough charge - sluggish start and certainly not enough to allow stop/start.

 

It's important not to overcharge a battery, as this will ruin it permanently.

 

Therefore, I usually just top up a little and check the voltage.

 

When I'm up to 12.2V to 12.3V measured through the cigarette lighter socket (without any lights turned on or other heavy electrical drain...as this will lower the voltage so you won't get an accurate voltage reading), I stop charging and let the engine's alternator finish off the charge when I take the car for a run.

 

Ring RCB4 Car Battery Charger (4A charge rate)

£17.99 on amazon

https://www.amazon.co.uk/Ring-RCB4-Essentials-Battery-Charger/dp/B00KQHVBZ0/ref=sr_1_67?dchild=1&keywords=car+battery+charger&qid=1613164870&quartzVehicle=29-405&replacementKeywords=car+battery&sr=8-67

 

Ring RCB104 Car Battery Charger (4A charge rate)

£20.72 on ebay

https://www.ebay.co.uk/itm/Ring-RCB104-12v-4-Amp-50Ah-Up-To-1-2L-Engine-Car-Motorcycle-Bike-Battery-Charger/200542843234?epid=4017010081&hash=item2eb148f162%3Ag%3AJ8YAAOxyA9dSUVPV&LH_ItemCondition=3

 

Ring's website

https://www.ringautomotive.com/en/battery-care

 

It's important to be aware of your car battery's capacity. If it's 60Ah then a 4A charger would fully charge it in 15 hours if it was completely flat. If it's 80Ah then a 4A charger would fully charge it in 20 hours if it was completely flat. Notice that to get the charging time, you divide the battery capacity by the charging rate, ie. 60Ah divided by 4A = 15 hours.

 

However, it probably won't be completely flat (it may just be a little low) in which case a 5 hour charge would add 5 hour x 4A = 20Ah of charge to the battery.

 

Don't try fully charging an AGM battery with the cheap Ring battery chargers above, because these Ring chargers will probably be for old fashioned non-AGM batteries (ie. sealed lead acid). However, you could use it for about 5 hours to top up a battery by about 20Ah.

 

Let's say your 60Ah or 80Ah battery is low and only has 20Ah of capacity remaining. Adding 20Ah of charge will bring the capacity up to 40Ah. You can then let the car's alternator/charging system finish it off when you go for a run.

 

It's probably not a good idea to use an automatic battery charger connected through the cigarette lighter socket, as the voltage of the battery is higher than the reading you will get through the cigarette lighter socket.

 

If you use an automatic battery charger, it's probably best to disconnect at least the negative terminal on the battery. This allows the automatic battery charger to get an accurate reading of the battery voltage.

 

Because of this need to disconnect the negative terminal on the battery before using an automatic battery charger, I just top up a little...and let the car's charging system finish the job when you go for a run. This prevents the battery from being permanently damaged by being over-charged.

 

Edited 12 February, 20215 yr by Carlston

Ring RCB6 Battery Charger 12V 6A

wilko £12.00

https://www.wilko.com/en-uk/ring-essentials-6amp-battery-charger/p/0426400

 

Ring RCB106 Battery Charger 12V 6A

amazon £21.99

https://www.amazon.co.uk/Ring-RCB106-Battery-Batteries-Vehicles/dp/B002PIQI60/ref=sr_1_3?dchild=1&keywords=ring+rcb106&qid=1613172827&sr=8-3

 

Edited 12 February, 20215 yr by Carlston

This thead also mentions  whether to leave the battery connected or not.

 

CTEK

If you look at the ct5 and mxs5 you will see:

 

the ct5 is 3.8A max and 14.7v max 

the mxs5 is 5A max and uses 15.8v during recon and phase1.

 

obviously you can avoid using recon, but the 15.8v during the initial charge stage can damage an AGM battery.

 

The mxs 7 appears to have the same profile as the ct5 but at a max 7amp

 

I would have thought your existing charger would be fine just to top it up, albeit over about 24 hours.

 

 

I don't understand that when the Mx5s has an AGM setting if it damages the battery.. 

11 hours ago, Carlston said:

It's probably not a good idea to use an automatic battery charger connected through the cigarette lighter socket, as the voltage of the battery is higher than the reading you will get through the cigarette lighter socket.

 

It shouldn't be a problem. There will be voltage drop along the wires so although a multimeter will show a lower voltage than the battery, when you charge it'll do the opposite. The wires certainly won't cause it to overcharge

 

12 hours ago, Carlston said:

If you use an automatic battery charger, it's probably best to disconnect at least the negative terminal on the battery. This allows the automatic battery charger to get an accurate reading of the battery voltage.

 

Because of this need to disconnect the negative terminal on the battery before using an automatic battery charger, I just top up a little...and let the car's charging system finish the job when you go for a run. This prevents the battery from being permanently damaged by being over-charged.

 

Leave the negative terminal connected but don't connect the charger to it. Instead, attach to the ground point as shown in the owners manual.

 

The battery monitoring system needs to see how much charge the charger is adding so the battery status and state of charge is correct. If you're disconnecting the battery to charge or charging it directly, ideally the car should be recoded to show a new battery has been fitted so it can relearn the characteristics/SoC etc.

 

 

While I agree that overcharging is bad, there should be little risk when using an appropriate smart charger for the correct battery technology

 

24 minutes ago, arnold said:

I don't understand that when the Mx5s has an AGM setting if it damages the battery.. 

 

Look at the manual for the 5 and 7

There was some discussion in a few places and the initial short 15.8v pulses   are bad for AGM batteries. 
 

Not potential instant death like the sun recon cycle, but shortens life.

 

Here is one such link but there are others out there with battery manufacturers stating it was bad too:

 

https://forums.mercedesclub.org.uk/index.php?threads/just-tried-out-the-ctek-ct5-stop-start-for-agm-batteries.159081/