Cheetah ,lead acid battery failure after two weeks ?

#1
Has anyone got an idea why a fairly new lead acid Cheetah battery acts dead just after what appeared to be a full charge (green light came on ) ? Then after pushing bike uphill home and re - charging the green light appears after one hours charge . Does this mean the battery has probably sulphated and cant hold a proper charge ? The bike has had about three hours use or less and travelled about 4-5 klms . The paper label on the charger shows the charger was made in May 2014 . Have i been unlucky and got a faulty battery ?
 

Ann M.

Administrator
#2
Not necessarily; it's more likely that one or both of the SLA batteries was bad or a couple of years old when you purchased the Cheetah battery. Find someone with a voltmeter to help you check the voltage output of the charger. The system is a 24V 12ah set, so the charger should be outputting at a minimum 27 to 28Volts to properly charge the batteries. It's more likely that the issue lies with the batteries and that will require someone who can do a load test on the batteries; voltage alone is not a good enough indicator of battery condition. One of your local battery shops or an ebike shop should be able to help you with this. It is possible to damage a set of SLA batteries in a short period of time if you leave them on the charger 24-7 when not riding; that ends up cooking the acid inside the cells releasing gas and causing the batteries to 'poof up'

Fairly new is vague, and in general, small SLA batteries (12V 12ah) only have a couple of years life span before needing to be replaced.
 
#3
Not necessarily; it's more likely that one or both of the SLA batteries was bad or a couple of years old when you purchased the Cheetah battery. Find someone with a voltmeter to help you check the voltage output of the charger. The system is a 24V 12ah set, so the charger should be outputting at a minimum 27 to 28Volts to properly charge the batteries. It's more likely that the issue lies with the batteries and that will require someone who can do a load test on the batteries; voltage alone is not a good enough indicator of battery condition. One of your local battery shops or an ebike shop should be able to help you with this. It is possible to damage a set of SLA batteries in a short period of time if you leave them on the charger 24-7 when not riding; that ends up cooking the acid inside the cells releasing gas and causing the batteries to 'poof up'

Fairly new is vague, and in general, small SLA batteries (12V 12ah) only have a couple of years life span before needing to be replaced.
Hi thanks for your quick reply :
Fairly new means two weeks . No i dont fry my batteries i have enough experience with vehicle repairs nor do i boil them . Im hawkeye watching them and monitoring their progress .
Fortunately i openened the battery casing and found the culprit , a loose soldering joint that hadnt been tinned sufficiently during assembly . The charging socket terminal just needed tinning then re-soldering the yellow wire . Easy job for me , and all seems well .Some nipped wires as they pass over battery edges but only outer wire covers. Could be down to rough handling in transport especially in Portugal as my wifes Cheetah took a bashing at the rear end distorting the frame severly , but i was able to use a cloth covered trolley jack handle to bend back some of the frame damage incurred in the transport .The main rear forks were not harmed and the bike is strongly made in general . Ive found one company representative easy to negotiate with and some compensation was offered which im quite pleased with . Its very useful to have two Dillenger Cheetahs to compare a part or exchange batteries etc .
A lot of interest has been shown in this Area of the Algarve in the bikes as theres some hills around and lots of retired people and generally great weather .
Ive cycled unicycles , tandems , made a reclining tricycle , in the past and own two three wheel cars . My feeling about the Cheetah is that its a fairly tame machine and trying to coax it faster results in a steering wobble prob due to the wide saddle and the small wheels and steering geometry combined . Trying to cycle it with a dead battery uphill is something else with just one gear . Doubt it will happen again .
As the motor hangs down quite low its vulnerable to some concrete slopes which aid wheelchairs to mount pavements . So ive improvised with a short length of white pvc rain gutter tailored to fit and strapped it on with plastic ties which protects the lowest point from accidental bumps . On my white Cheetah it looks like an original fitting .
 

Ann M.

Administrator
#5
Aidan, it's nice to work with someone who's not afraid to pop the top off a battery and check connections; it's not an uncommon problem that we see along with poorly manufactured Asian SLA batteries. It's definitely not fun to pedal a heavy ebike back uphill. Your creativity with the motor mount is worthy of a pic or two to share here, please.
 
#6
I'd the problem + my 1, not full charge on bike, but then green LED showing charged on charger. & sometimes loose all power on bike. Opened up battery case & found wire from charging point'd come loose, & sometimes sorted out, soldered it.
 

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