Battery Charger

elect70, Aug 22, 9:39pm
smart battery charger isnt so smart . It wouldnt charge battery that is dead flat , loaned mine to next door as she had left park lights on all night , but it didnt do anything . Nearly going to tell her battery was stuffed until Ii had an idea & connected 12 V kontiki battery in parralell &left it for 10 minutes . Then connected charger & started charging at 5 amps& rose to 15 . trap for uninitiated
skull, Aug 22, 9:44pm
The smart charger may still have been thinking and devising a cunning plan.
cjdnzl, Aug 22, 9:54pm
Sounds like she has a calcium battery. There are calcium chargers available that will charge them from flat, but ordinary chargers won't. In any case, if the battery is/was dead flat then it's compromised, she should ditch it and get a new one.
tony9, Aug 22, 9:55pm
Well her battery is stuffed. Getting a modern car battery dead flat even once effectively ruins the capacity of it.
tweake, Aug 22, 10:08pm
a lot of electronic chargers won't charge a battery unless its got a certain voltage left in the battery.
jumping it with another battery like you did gets around it. its gets the voltage up enough for the charger to kick in.
but odds are the battery is stuffed

my oldish charger is manual/auto. if i get a battery like that i can put it on manual which bypasses the electronics.
elect70, Aug 23, 7:53pm
^^ yep i remember my old Arlec charger would recharge my kontiki batteries from dead flat as .It didnt have any cutoff just let it run out until batteries went flat . They lasted 3 years though. . Any way shes got it going &suggested she should buy new 1 if has any trouble starting .
ajm43, Aug 25, 4:04pm
Most batteries that are sealed ie no caps, are calcium type, and do not like being charged from dead flat. #5 good idea and may well work.
elect70, Aug 25, 8:37pm
^^ I usually buy Exide from red shed doesnt say calcium on them so presume its just standard lead acid .
intrade, Aug 25, 9:17pm
what smart charger brand my one the ctek goes and pulses the battery for a wile. i guess its to see if it can tickle it back to live
i had the hilux parked up came back dead flat. did think a rat eat something so removed battery put on ctek and 30 minutes later fault light was on so i put it on the supercheap smart charger selected calcium button and charged it. it got to 12 volt but no load multimeter now mesured 12.6 volt but the voltage drop test showed it went to 3 volts instantly , so the ctek was right that the battery was faulty and did not even bother with it.
intrade, Aug 30, 6:33am
i dont know if you even can get non calcium batterys these days i have not found one the calcium might be in the code of the battery not in words.