I have two 8Amp battery chargers that I use on my mobility scooters that
Do you know someone or a company who can repair them please.
Each battery charger new is about £145 and I don't really fancy binning
They are usually perfectly normal sealed lead acid chargers (24v or
12v). Maplin do a rather nice one (L16BQ) for <60GBP, if push comes to
shove and you need a 12v unit.
You may find that your local REMAP panel have contacts that can get them
mended for free/ not a lot. It's the sort of thing I do for my local panel.
I've got several scooter chargers in stock - but they are all 24v units
and are moulded units that are normally built-in to the scooter.
There will be a transformer rectifier unit plus a controller of some sort, a
sealed unit full of electronics probably these days. Without test meters you
can't check the rectifier unit or the electronics and if the transformer
isn't burnt out you are stumped.
I think there's been some serious changes in the chargers used for scooters
in the past few years.
We recently bought a new mobility scooter, and the charger doesn't look much
different to the charger for our laptop.
Obviously the plug where it connects to the battery is different, but other
than that, it's a world of difference from the big bulky car-battery style
charger that the old scooter came with.
Oddly, the plug on this charger is exactly the same as the ones fitted on
Huh? most of the ones I have seen for lead acid anyway are just
transformer rectifiers..with enough impedance in them to reduce to
trickle as the battery voltage nears 'fully charged'
Nickel cells unless you want fast charging are just low constant current
The "impedance in them" limits the initial charging current. It does not
cause the current to reduce to a trickle.
Trickle chargers limit the current to a trickle at all times. They are
safe enough, but will typically take >10 hours to charge a battery.
Cheap "transformer rectifier" chargers are unregulated. They may easily
charge at too high a rate during initial charge and have too high an
output voltage to leave "charging", once the battery is charged. The
final "trickle" charge is determined by the charger output voltage - not
Nope. The impedance of the supply has to be low to deliver a high normal
charging current. Unless that impedance is altered as the battery
reaches its charged state (ie not a cheap transformer-rectifier
charger), the supply impedance remains low - too low to affect the
trickle current level.
You forget that I=Vdiff/R..drive from a low voltage and the current
reduces as the battery charges. However in theory at least, and rather
horrendously in practice sometimes, a low power supply impedance will
ultimately end up in I tending to infinity with the usual result..
Nope. The I decreases because the Vdiff decreases - not because R
increases. R remains constant. Even cheap chargers usually limit Imax
for high VDiff - too many people connect chargers to car batteries with
the 6v<>12v slide switch set incorrectly. Things have moved on from
selenium rectifiers and moving iron meters..
However, the basic point is that "cheap and cheerful" car battery
chargers should not be used with batteries of the type normally fitted
to mobility scooters. It certainly can end up with things heading
towards infinity - such as bits of the battery. ;)
No, I think he means a blade-type fuse.
However, some preset output chargers use a resistor built into a
"blade-type fuse" link to set the charging profile and even battery type.
They come with a range of different links for the new owner to choose from.
A third party, seeing one of these and thinking it just a fuse, could
cause a lot of damage replacing it with one..
On Wed, 27 Jun 2007 08:45:47 +0100, "the_constructor"
That sounds like a ripoff.
A quick search seems to prove it
And even that seems a bit heavy.
The scooters I've seen both used sealed 12 volt lead acid batteries. A
normal car charger would have charged them.
Try a local auto electrician if you must have them fixed but I'd nip
into the local car accessory shop and just get normal charger. Or buy
one of those £26.50 ones
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