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Do any of the manufacturers use a balancer in their scooters between the cells? I know they are used in model airplane batteries and with some kinds of batteries can be needed.
With what battery types are they a good idea and where would a balancer be a waste of money?
"If my grandmother had two wheels she'd be a bicycle ... so what? Things are the way they are, and it places where they are not that way things are different, that is the nature of things." (Thalassamania)
I'm not an electrical engineer, so I may be corrected, but I am a hard core DIY guy and have worked with all three battery technologies quite a bit.
A balancer would be a waste of money and reduce efficency of the circuit for the type of batteries used in all of the scooters I'm aware of today. Because all of the cells within each bundle are of the same type and used at the same rate they do not get out of balance. They drian at the same rate and charge at the same rate unless a cell is bad, which a balancer would not fix anyway.
The only exception I could think of would be if the scooters uses two seperate cell bundles for it's power supply, but the batteries are charged seperatly befofre use. And even then it would only apply if a person were to use the two cell bundles when they were very far off in state of charge to start with, like using one fully charged and one only half charged battery pack.
"If my grandmother had two wheels she'd be a bicycle ... so what? Things are the way they are, and it places where they are not that way things are different, that is the nature of things." (Thalassamania)
"If my grandmother had two wheels she'd be a bicycle ... so what? Things are the way they are, and it places where they are not that way things are different, that is the nature of things." (Thalassamania)
If you can charge the individual cells (i.e. have electrical access to each cell) you don't need a balancer. Lead acid technology does not require it because all "cells" in the battery are chemically connected by the electrolyte anyway.
NiCad (somewhat), NiMH, and certainly Lithium Ion (all types) require balancing, especially for high discharge rate applications such as electric model airplanes. I see this as less of a factor in low (below 1C) discharge rate applications or where the cells are of excellent or world-class quality.
A balancer would be a waste of money and reduce efficency of the circuit for the type of batteries used in all of the scooters I'm aware of today.
Since the cheaper scooters use SLA technology, this is likely to be true. However, I have seen some of the better ones using nickel metal hydride batteries and these SHOULD be balanced. On the other hand, I would be surprised if the manufacturer didn't include balancing as an integral part of the charging circuit.
Since the cheaper scooters use SLA technology, this is likely to be true. However, I have seen some of the better ones using nickel metal hydride batteries and these SHOULD be balanced. On the other hand, I would be surprised if the manufacturer didn't include balancing as an integral part of the charging circuit.
I've not opened up and dug around in any of the high end battery packs, but from the outside they look like bundled cells, mostly unprotected 18650's and I haven't seen any circuit in the battery packs between cells, just wires. Now you got me curious and waiting to hear from a manufacturer. As far as the charging, with so many cells doesn't it just equate to having lots of cells on a trickle charger in parallel? If there were a balanced charging circuit wouldn't the charger have to have more than just two wires leading to the cells? Can someone look at a Dive Xtra or SS scooter and tell us how many wires come out of the battery pack? If it's more than two, I'd say you are right.
As far as the charging, with so many cells doesn't it just equate to having lots of cells on a trickle charger in parallel?
Not exactly. Balancing literally means insuring the same charging voltage across each cell in the end without letting one cell in the pack regulate the current. "Trickle" is a bad idea with lithium secondaries.
I am not a big fan of "blind" parallel charging of series packs. This is a definite DO NOT DO in the case of NiMH technology, as these cells drop their internal impedance at maximum charge, leading to the first cell to reach that point in the parallel connection to quickly descend into a run-away overcharging state. Been there, done that - it is a smelly mess to clean up.
My best advice is to use what the manufacturer gave you, unless you're sure it's a cheesy piece of junk (which it IS in many cases) -OR- a good "smart charger" like the electric RC crowd uses. If you want specific recommendations for your battery type, let me know.
Not exactly. Balancing literally means insuring the same charging voltage across each cell in the end without letting one cell in the pack regulate the current. "Trickle" is a bad idea with lithium secondaries.
I am not a big fan of "blind" parallel charging of series packs. This is a definite DO NOT DO in the case of NiMH technology, as these cells drop their internal impedance at maximum charge, leading to the first cell to reach that point in the parallel connection to quickly descend into a run-away overcharging state. Been there, done that - it is a smelly mess to clean up.
My best advice is to use what the manufacturer gave you, unless you're sure it's a cheesy piece of junk (which it IS in many cases) -OR- a good "smart charger" like the electric RC crowd uses. If you want specific recommendations for your battery type, let me know.
Sounds like you are deeper into this than me. Not my post to start with, but still appreciate what I learned here.
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Originally Posted by TheDivingPreacher
