How low is too low

[GeekOKent]

Hi,

Just checked and my deep cycle Hankok 110ah (says dual purpose, can also be used as a starter ) has dropped to 2.4v. Not missing any digits, the meter really does say 2.4v

The ctek wont charge it, it wont even see it. I suspect down to these smartchargers not liking anything less than 7 (?)volt or.is it 9?

My starter pair is matched so one option was to replace one of the starter pair with this one, and expose it to the full wrath of the 110amp alternator.. but is that then goig to impact the exiting battery left in ( from the starter pair)?

A more painful option is maybe to remove both the units from the starter pair, wire this one in, jump the 105 from one of the starter pair, and go for a long drive ( i am on the road for 4 hrs tonight ). I will need to keep one of the good starter bttys in the boot though.

The other option is I have an old halfords car charger, that is about as smart as a a piece of stick. It does have a 14.4v option as a 'sealed' charge type. Is that a good way to bring this ine up and then let yhe ctek d250 do its thing? Is the ctek evem going to see it at all?

Or am.I just looking at a new battery here.. unsure how it got so low in the first place. It was at full charge early nov and has just been sitting in the garage since. ( i used it to check some led light panels a couple of times, but nothing major and certainly nothing for more than 15 to 20 minutes.

Regards and as always thanks for any advice

 

[LC80tim]

You could try putting some jump leads from your running motor to the battery for a while to bring it up on voltage and then charge after, just a thought

 

[StarCruiser]

Exactly my thoughts Tim. However, if this doesn't prove practical given the 4hrs travelling due, a spell on the Halfords charger might just help bring it back from the breach. Warm it up a bit too but don't bring it into the house as it will probably give off some fumes and at least stink the place out. Keep an eye on it though, see that charger doesn't boil it. Check the electrolyte is covering the plates, top up with distilled water if necessary. Monitor the voltage and get it connected to a Ctek as soon as one will work.

They don't like being over discharged KB, but the Cteks are like paramedics. If anything can they can. Leave it on for at least a week, ideally permanently while the battery isn't being used.

 

[Towpack]

The problem with Cteks and many other 'smart' chargers is they have a threshold below which they won't see a discharged battery. My 'Aldi' charger (just as good) is the same. Try connecting a second, charged or part charged battery in parallel with the dead one. Then connect the charger which should see the good battery and, hopefully, start charging them both. Keep an eye on the dead battery though for signs of overheating or excessive gassing. If it's only deeply discharged and not actually damaged then it shouldn't be a problem.

 

[hopeless wanderer]

Hi,


Regards and as always thanks for any advice

The problem with Cteks and many other 'smart' chargers is they have a threshold below which they won't see a discharged battery. My 'Aldi' charger (just as good) is the same. Try connecting a second, charged or part charged battery in parallel with the dead one. Then connect the charger which should see the good battery and, hopefully, start charging them both. Keep an eye on the dead battery though for signs of overheating or excessive gassing. If it's only deeply discharged and not actually damaged then it shouldn't be a problem.

The battery in parallel thing worked for me previously, I didn't have a multimeter so i don't know how low it got but it wasn't "seen" by the charger i had at the time. I've since invested in a Noco g7200 that has a function that dishes out the current irrespective of the state of discharge. It also apparently revives batteries that have suffered sulfation.

 

[Crispin]

Be careful with the jump leads. I would connect the ctek then tap the jump leads on until there is enough of a charge for the ctek to kick in.

If you connect them and leave them then the good battery will dump a lot of current into the flat one. Might cause heating and buckling of the plates.

You've not done it any favours but if you charge it now then there'll be minimal damage.

 

[GeekOKent]

Thanks for all the great feedback. I put it on along with a good battery for the drive yeaterday. Arrived and it was showing 12.4v.

Will be back home at night today, will get it into the ctek. Should kick in now.

Rich, its all sealed so no way to get electrolyte check /level etc.

It did not get warm at all, but i also made sure it wasent getting anymore than 14v at any time.

 

[StarCruiser]

A battery should bulk charge at 14.4v. As Cris says, that equates to a fairly hefty charge current into the depleted battery.

Electrolyte levels can sometimes be checked by shining a light through the battery if it's made from translucent plastic of course.

You do need a good voltage to get the battery accepting a charge and start 'gassing'.

 

[GeekOKent]

Got back, battery in the ctek, now charging there. In a couple of days will put some load on it and see how it goes.