please help! 48v to 60v upgrade

[budafuko]

hello everybody. i am hoping somebody can help me.
i have an eagle 48v ebike with an 800w 48v 60 degree 33+-a controller
i have recently gotten my ebike upgraded to a 60v but for some reason when the bike is charged past 64.9v the motor will not spin
i have to reconnect it as a 48v and run it for a little while then reconnect the 5th battery.
as you can imagine this is getting to be annoying and i am worried about the levels in the 5th battery always being different for charging reasons
i was hoping one of you good fellows would be able to help
any help is appreciated!
thank you!

 

[Willow]

You have not really given enough information for people to help you.... but

It's most likely your controller is not operating at the higher voltage because it has a safety cut-out at the high voltage end so it won't fry itself. You will need a new controller, preferably one that is rated to at least 72V and is programmable.

s.

 

[ARod1993]

A lot depends on the controller; a lot of 48V motor controllers will use 63V-rated capacitors and 60-70V FETs, and so running the bike at 65V or so is not recommended unless you check the voltage ratings on the caps and FETs and determine that they're at least a few volts higher than your hot-off-the-charger pack voltage. If the controller works when run at 48V, but does nothing when plugged into a 60V pack, and then works fine again below 64.9V, then there's probably some sort of overvoltage shutdown condition in the controller software designed to protect it from capacitor and MOSFET damage. As far as running four batteries and then throwing in the fifth one partway through that's not the best for the batteries and (at minimum) won't give you much extra run time and may give you pack balancing issues.

If you're intent on running at 60V, then your best bet from a reliability standpoint is to replace the controller with one that's rated for 60V or 72V nominal (at which point a 65V+ pack ceases to be an issue). The other option that you have (although I would advise cracking open the controller and checking to make sure that the caps and fets are actually rated for >65V (rather than being rated at 63V and surviving because they're ever so slightly underrated) before you get into the habit of doing this) is to only charge the batteries up partway (this is more feasible with lithium batteries than lead), so that each battery reads 12.95V or so open circuit at the conclusion of your charge cycle. You won't get quite the same range that way as you would with a 60-72V controller and fully charged batteries, but you'll get more than with a 48V setup, and (especially for lithium batteries) cycling them between 80-90% SOC and 15-20% SOC is actually easier on the battery than charging them up all the way and then going down to 15-20% SOC.

 

[budafuko]

thank you very much for your replies. i am new to the ebike craze and wasn't sure which information i needed to give. my apologies
your input has been very helpful. i imagine a 48v to 60v breaker wouldn't be that great considering you said i wouldn't get any more range switching between 48v and 60v. also you stated this (could) be harmful for the battery packs. someone told me the same thing about charging to 64.9 (5x12.98) untill we could "diagnose and figure out the problem". someone else also told me that lead acid batteries level out if plugged into series and turned on. i am not sure how entirely accurate this is. again thanks for all ur help.. please confirm for me that the breaker idea is no good. i know its pretty much the same thing but i am a stupid dick


p.s. what is 15-20% life on a 60v system?
also out of curiosity. same question for 48v

thank you very much

 

[dnmun]

no info. not even the brand of the controller or the actual voltage of the charger for 5 12V SLA in series which would normally be 72.5V or about 10V more than the input caps can handle. do you have a voltmeter?

 

[budafuko]

sorry. it is an eagle controller. 800w 48v 60 degrees 33+-a they are 12v 20ah batteries
im using a 60v 3a charger to charge all 5 batteries in series
my bike has a voltmeter built into it. i have no external meter

also i noticed a full charge is about 73 and drops to about 67 when unplugged (a mere 2.1 volts over my threshold)


thank you

 

[dnmun]

a 48V controller should have an LVC of 40V so it is not cutting out for LVC but it may have an over voltage detection that shuts down the input. i have heard people talk about them but i have never seen a controller with a HVC cut off.

in any case that is gonna be too much voltage for a 63V input cap. or maybe for the mosfets too. but less likely.

 

[budafuko]

i read online that the controller may or may not have a HVC loop wire that connects to the battery at the end of the series.i also read that this wire can be connected just before the extra battery in the series to trick it into reading 48v. however, this was for lithium batteries, i imagine it would be about the same.

looking at the controller is useless (so many wires i cant tell what is what) and i know nothing about them as of yet so i do not want to unhook it. its put togeather poorly all jumbled. i got ripped off and dont want to talk about that aspect of it lol

i was thinking shunt mod but then thought if there is a HVC loop wire then a shunt mod wouldn't even solve my problem and like i said i dont want to take it apart

i think maybe a new controller is my only option aside from charging it to 66v and unplugging. leaving high beams on for a few minutes if neccesary

if anyone knows different please let me know

also if anyone knows of a good controller for cheap please let me know as well
thank you

 

[dnmun]

i doubt if it is a HVC wire dedicated to just one function. that wire is probably the circuit current for the controller and you could do like they say and bypass the last battery for the circuit current and then connect the power lead for the mosfets to the top of you 5S 12V SLA stack. but that may blow the input caps if they are 63V but it might work for awhile and then you could replace the input caps with some 100V ones.

 

[XLR8]

I have a 24 FET greentime controller that is set up for 20s LiFePO cells. It will not run on 24s and the caps inside would have to be upgraded also. This is the first controller that I have had that will not run on higher voltages.

 

[Willow]

a 48V controller should have an LVC of 40V so it is not cutting out for LVC but it may have an over voltage detection that shuts down the input. i have heard people talk about them but i have never seen a controller with a HVC cut off.

in any case that is gonna be too much voltage for a 63V input cap. or maybe for the mosfets too. but less likely.

Kelly controllers have an 'over voltage' setting - adjustable in the programming.

 

[dnmun]

you can open the controller and take some close up pictures of the insides and we can offer advice about how to hack that controller so you can use it with that 60V battery.

 

[budafuko]

thank you very much again

it is forcasted to rain where i am so i will do it on an other day (close up pictures). i imagine i can get the top off without disconnecting anything. sorry for the delay