Have recently acquired two pre owned electric bikes with throttle switch on handlebars.They have not been used for a number of years and I was aware I would have battery problems.Have charged one of the 36 volt (3x12) battery packs up and a voltage meter tells me it is pushing out 22 volts.When I place battery pack back on bike lights and horn work ok but power gauge showing state of battery reads empty and no power comes from the throttle.Fully aware batteries are useless but surely power gauge should show a little charge and throttle would give a little bit of power.Tried battery pack on the other bike and same applies also checked fuses on speed controller.Any suggestions would be appreciated as I paid a lot of money for these and the wife is likely to string me up If I don't get it sorted. Bikes are Ecolux Uk Tornado Electric Bicycles.
Not a clue.
- Thread starter bill alexander
- Start date
A batteries BMS or the controller both have a low voltage cutoff system of 30 - 33v or there abouts so with 22v you have got no hope. The batts are shot you will need a reading of 34/35v for them to work a tad. Time to ditch the SLA's and upgrade to Lithium but wifey won't be amused at the price.
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Deleted member 4366
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A guy on the forum possibly has a couple of those batteries for sale. Check the classifieds and then check the size .
Thanks for your replies guys.Am I being a bit thick here but if you use the bike on a trip the voltage would drop.The following day if you switch on the power gauge would you not get a reading even if battery had discharged below say 20 volts.What does BMS mean Nealh,
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Deleted member 4366
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The gauge probably only works between 30 and 40 volts because that is the working range of the battery. 20v means that they're completely scrap. You can't bring them back to life from there.
Bums is battery management system.
3* 12 volt batteries should deliver power until the voltage is down to 33volts after that the cells die. One dead cell will stop the whole system from delivering. Lots of dead cells mean you get 20 volts after charging and no power for the motor. Time for new batteries. Billyboy has got new lead acid batteries, then on advice got lithium. The lead acid it a cheap short term thing. Spending £300 ish on new batteries makes buying a whole new bike an idea worth thinking about.
Sorry about the miss's but mine thinks I'm always wrong too
3* 12 volt batteries should deliver power until the voltage is down to 33volts after that the cells die. One dead cell will stop the whole system from delivering. Lots of dead cells mean you get 20 volts after charging and no power for the motor. Time for new batteries. Billyboy has got new lead acid batteries, then on advice got lithium. The lead acid it a cheap short term thing. Spending £300 ish on new batteries makes buying a whole new bike an idea worth thinking about.
Sorry about the miss's but mine thinks I'm always wrong too
Modern lithium batteries have a protection system called a BMS ( Battery Management System) in the way of a small printed pcb wired to the cells, for 36v batteries it monitors charging (42v max) and discharging (32/33v min) to protect the cells. Most 36v (Nominal voltage) batteries will have a LVC threshold at about 33v once it detects the battery voltage is down to this level it cuts all power to the controller which runs the motor, allowing voltage to go lower will ultimately cause undue stress and damage the cells. Once these cells are damaged actual battery capacity (Known as Amp Hours or ah) will suffer though will still give a high charge voltage if only a few cells are damaged.
In your case your SLA batteries will not have a BMS but the bike will still have a controller with a pcb which will have its own LVC threshold (29/31v) this acts like the batteries BMS when the bike is in use.
Your SLA's are shot at 22v, each battery is approx 7.6 - 7.7v so no where near a healthy 12v nominal rating which they should be at or nearly half of the full voltage when fully charged at 14v each.
In your case your SLA batteries will not have a BMS but the bike will still have a controller with a pcb which will have its own LVC threshold (29/31v) this acts like the batteries BMS when the bike is in use.
Your SLA's are shot at 22v, each battery is approx 7.6 - 7.7v so no where near a healthy 12v nominal rating which they should be at or nearly half of the full voltage when fully charged at 14v each.
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You may be able to revive your sla batteries... Good car repair shops often have a charger designed to oscillate whilst charging which can significantly weaken sulphurous coatings of the anodes. I think they might be called "percussive chargers" but I'm no expert.
Your car mechanic may know more but a tenner to the mechanic may revive one.
Worth a try I think, from what you say. And get her something nice too...
Your car mechanic may know more but a tenner to the mechanic may revive one.
Worth a try I think, from what you say. And get her something nice too...
D
Deleted member 4366
Guest
I've got one of those. It doesn't work on SLAs, and I didn't get much success with car batteries either.
Thank you gentlemen for giving up your valued time giving an ignoramus your simple explanations.Me thinks the bikes must be sold pronto.
I'm for selling these bikes explaining batteries need replacing unlike original seller.Wife does not want to saying replace one battery pack and seeing the result.I am still reluctant as battery replacement does not guarantee bikes will work.What do you think?