Charging 48v 14ah battery bank ???

[markus19]

Hi guys i have owned a electric scooter for a while
it has a battery bank on it that is made up of 4x 12v 14ah
sealed lead acid batterys.

i would presume this would make it a 48v 14ah battery

The bike has sat in my shed for few years and i am now
wanting to sell it.

so the other day i turned it on and the lights were flashing
and all working but i presumed the battery would be quite
flat having not charged them for ages...

i couldn't find the charger anywhere so i bought a new

48v 14ah charger from china that fit the bike.

it came i plugged it into the battery the green light flickered
for abit then it went to solid red the few hours later green

i though this would now mean fully charged so i unpluged
the charger and the next day went to fit it to the bike..

now when i turn the key there was nothing total dead

i opened up the battery bank case and found the 4x
battery all baked and bulged... like they had been overcharged

but the charger is suppose to have overcharge protection
so can any one tell me what has gone wrong...

 

[UKMeterman]

Hi guys i have owned a electric scooter for a while
it has a battery bank on it that is made up of 4x 12v 14ah
sealed lead acid batterys.

i would presume this would make it a 48v 14ah battery

The bike has sat in my shed for few years and i am now
wanting to sell it.

so the other day i turned it on and the lights were flashing
and all working but i presumed the battery would be quite
flat having not charged them for ages...

i couldn't find the charger anywhere so i bought a new

48v 14ah charger from china that fit the bike.

it came i plugged it into the battery the green light flickered
for abit then it went to solid red the few hours later green

i though this would now mean fully charged so i unpluged
the charger and the next day went to fit it to the bike..

now when i turn the key there was nothing total dead

i opened up the battery bank case and found the 4x
battery all baked and bulged... like they had been overcharged

but the charger is suppose to have overcharge protection
so can any one tell me what has gone wrong...

The batteries are knackered leave lead acids without charge for more than 6 months is asking for trouble.

One or more cells will have failed and unless the charger has a timer it will never see the high voltage to end the charge. And any cells which have partialy failed will go to high volts and gas before the others.


Get some replacments at CPC / Rapid Electronics

 

[markus19]

The batteries are knackered leave lead acids without charge for more than 6 months is asking for trouble.

Get some replacments at CPC / Rapid Electronics

So is it defo the batterys i dont want to spend
on another for batterys and then the charger blow
them aswell.... the ones that were in wernt total flat
but now there total blown after being charged...
what is it that goes wrong with them.of there left
without charge that means when you do charge they blow

 

[telectrix]

batteries were probably in parallel, so should have used a 12V charger 9 maybe 24V if a series/parallel arrangement). either way you've cooked 'em with over voltage. tough lesson.

 

[UKMeterman]

Hi,
Look at the pics, looks like series to me...

 

[telectrix]

if so, then the batteries are goosed through age/standing for years. no option but to buy new ones.

 

[UKMeterman]

Hi,
Also beware of cheap chargers, terminating a charge correctly, particularly at higher voltages is not trivial. Best get the proper charger from a wheelchair place.

 

[markus19]

See thats the thing i dont want to buy another 4
batterys and them get baked again by the charger..


the charger led light went from a flicking green

to a solid red which a presume was charging

then in the end a solid green with the fan running

i would of though if the charger had over charged
it would not of went green just stayed red
and kept putting to much charge in....

but something must of triggered the charger to.turn green from red

 

[HandySparks]

...so i bought a new 48v 14ah charger from china...

Ha!

£10 for the charger, including delivery from China. Another £10 for the instructions to tell you what the lights mean.

 

[markus19]

Ha!

£10 for the charger, including delivery from China. Another £10 for the instructions to tell you what the lights mean.

Haha i had abit of forward thinking and sent a photo
of the instructions to a china chick on meow chat
turned out she couldnt understand them!!! :-(


im not to sure im any further on

everyone seem to have a diffrent answer

from

the batts being stored to long
putting in to much voltage
poor charger

so what can i blame....

as far as i now know if you link 4x 12v batts in series

you can charge with a 48v charger but what ah does it have to be at..

the same as tge batts which is 14 .

more than this or less

 

[Lucien Nunes]

There's not enough info here for us to help you. Old lead acids that have been standing discharged or nearly discharged for ages will be dead, and can malfunction in various ways and confuse the charger. So the precise sequence of indicator lights don't tell us how the charger will behave with a good set.

What is the output current of the charger? I would suggest something in the range of 2-4A for this capacity of battery. Is it 3-step? If so, then it will output its maximum current until the batts reach a certain state of charge, then usually the light will change perhaps from red to something flashing. It will then allow the current to fall and the voltage to rise, to equalise the battery just below gassing point, then after a certain time and/or below a certain current, it will drop to float mode, the voltage will fall and the light change again, usually to green.

You can monitor all this happening with a voltmeter, as well as the temp with your hand. If you see the voltage exceed about 58V in equalise, or the batt temp rises by more than a few degrees, you know the charger is overcharging.

 

[PEG]

All of these type of machines i have messed with,have the same issue with the most popularly failed components,being the most expensive,ie; the batteries. If you invest in a set,it is prudent to ensure the correct charger is selected,and not a cheap generic one via ebay. Some of the better quality machines use 24V,pairs in series,quads series/parallel. Due to the nature of their use,sporadic,deep discharge and long periods of outdoors storage,a charger with the capability such as Lucien describes,is vital. They are hard to find a customer for,if the batteries are suspect. :icon12:

 

[markus19]

ok guys here is a link to the charger i got
i know it was cheap and from china but so
was the bike so the plug fitment matched right


14AH 48V Lead Acid Battery Charger For Electric Bicycle Bike Scooters | eBay


i plugged the charger in and a faint flicking green light came on
and it was sort clicking like sort of pulsing

then when i came back maybe hour later it was bright solid
red and the batt case holding the four batterys was quite warm
then when i came back bout 5 hour later the light was solid green
the fan was running on the charger and the batt holder case
was really warm i then unplugged it thinking it had charged fine
until it didnt work then when i opend up the batt holder case i so
the four batts had been baked as all the plastic was buldged...

 

[Lucien Nunes]

If the batteries got really warm, the charger is suspect even though the batteries are also suspect.
But to my mind, the charger is suspect anyway if it really only costs £7.32. For comparison, the best price I can get on a professional quality charger of similar rating is about £90. OK that's a consumer product but it is difficult to imagine how they can do a proper job at that price. Caveat Emptor...

 

[PEG]

If the batteries got really warm, the charger is suspect even though the batteries are also suspect.
But to my mind, the charger is suspect anyway if it really only costs £7.32. For comparison, the best price I can get on a professional quality charger of similar rating is about £90. OK that's a consumer product but it is difficult to imagine how they can do a proper job at that price. Caveat Emptor...

...Wise words,but not as educational as Romanus eunt domus...:icon12:

 

[davesparks]

Romani ite domum, surely!

Now write it out 100 times before sunrise or I'll cut your balls off!

 

[Lucien Nunes]

The Electrician's forum - from faulty SLA chargers to faulty latin declensions in two easy steps.
Of the charger I would suggest pressura nimium nimiumque durationem. Corrections invited!

 

[davesparks]

The Electrician's forum - from faulty SLA chargers to faulty latin declensions in two easy steps.
Of the charger I would suggest pressura nimium nimiumque durationem. Corrections invited!

I haven't got a clue about Latin, but I do know a quote from Monty Python when I see one!

 

[PEG]

Cheers for the smile :icon12: Sicut amici;mens est rare...