Einhell Intelligent Battery Charger 2A - £18.71 @ Amazon

The problem with "intelligent" chargers is that they have a very high minimum level at which they will operate.
A 12v battery normally holds about 13.4v, but if you let it get below around 11v then you will have to either get out an old school charger to bring it above the threshold, or connect another battery that has charge, + to +, - to -, to bring the average up and then connect the "not very intelligent " charger.
Been there, done that, and almost paid out £100 for another battery. Luckily I read an article.

TristanDeCoonha19/05/2022 16:45

The problem with "intelligent" chargers is that they have a very high …The problem with "intelligent" chargers is that they have a very high minimum level at which they will operate.A 12v battery normally holds about 13.4v, but if you let it get below around 11v then you will have to either get out an old school charger to bring it above the threshold, or connect another battery that has charge, + to +, - to -, to bring the average up and then connect the "not very intelligent " charger.Been there, done that, and almost paid out £100 for another battery. Luckily I read an article.Read lessRead more

From the comments I read this doesn’t have this problem but I can’t substantiate…

TristanDeCoonha19/05/2022 16:45

The problem with "intelligent" chargers is that they have a very high …The problem with "intelligent" chargers is that they have a very high minimum level at which they will operate.A 12v battery normally holds about 13.4v, but if you let it get below around 11v then you will have to either get out an old school charger to bring it above the threshold, or connect another battery that has charge, + to +, - to -, to bring the average up and then connect the "not very intelligent " charger.Been there, done that, and almost paid out £100 for another battery. Luckily I read an article.Read lessRead more

Completely agree.

Problems are not uncommon.
chargingchargers.com/tut…tml

TristanDeCoonha19/05/2022 17:33

Problems are not …Problems are not uncommon.https://www.chargingchargers.com/tutorials/battery-recognition.htmlRead lessRead more

A "problem" which is easily solved by the smart charger companies adding in a simple switch to modify the minimum acceptable voltage threshold called "dead battery mode", however they reserve that for the far more expensive smarter models.

TristanDeCoonha19/05/2022 16:45

The problem with "intelligent" chargers is that they have a very high …The problem with "intelligent" chargers is that they have a very high minimum level at which they will operate.A 12v battery normally holds about 13.4v, but if you let it get below around 11v then you will have to either get out an old school charger to bring it above the threshold, or connect another battery that has charge, + to +, - to -, to bring the average up and then connect the "not very intelligent " charger.Been there, done that, and almost paid out £100 for another battery. Luckily I read an article.Read lessRead more

They are fine at 6v and above. I had a battery down to about 4v sitting for 6 months, got a booster on it to 6v and the charger kicked in.

Although at 2amps this would take a 70Ah battery about 35hours to charge, I bought the 8amp version not Einhell but similar. (edited)

TristanDeCoonha19/05/2022 16:45

The problem with "intelligent" chargers is that they have a very high …The problem with "intelligent" chargers is that they have a very high minimum level at which they will operate.A 12v battery normally holds about 13.4v, but if you let it get below around 11v then you will have to either get out an old school charger to bring it above the threshold, or connect another battery that has charge, + to +, - to -, to bring the average up and then connect the "not very intelligent " charger.Been there, done that, and almost paid out £100 for another battery. Luckily I read an article.Read lessRead more

Nonsense. They're not very intelligent then.

Noco Genius chargers can recharge batteries from as low as 0v. There are others like CTEK than can recharge from as low as 2v.

Stay away from Chinesium knock-offs. (edited)

PAcdbOoAct19/05/2022 20:20

Comment deleted

Which shows it is down to the charger, and the buyer needs to check the specs before purchase. As my link showed, there are many more out there that have fallen foul of this.
This being the case, whilst I would recommend the Lidl charger, it does fail in this aspect, and it took a 20 year old charger found in the shed to get me out of the poo, and even then it took 2 days to get bacj to 100%