In some cases pretty quickly
over a week or so. With extra electronics such
as remote start, or say the computer in the boot of my wheelchair adapted minivan that controls the
ramp, electric doors, suspension lowering and more the battery has double the drain on
it while I get out and then again whilst it is sat unused on my drive!
ordinary car starter batteries quite fast through sulphation even if there is
enough energy left to start the engine most of the time. So you will not
anything is wrong. Your battery will just suffer an early expiry. See
powerchair & vehicle batteries for
Every time you
switch off and get out, the ramp and suspension lowering (on my car
for E.G.) as well as
the door opening and closing motors all use lots of power. Your battery is already in a slightly discharged condition
after you just exit it after a
long drive. Batteries store or age well in a fully charged state. But they
all sulphate internally if left in even a slightly discharged
state for very long.
In a relatively short time the batteries capacity or starting capability is
the fact that all those electrical systems mentioned above are still gradually
taking even more power out, over time, as it sits there on your driveway.
So if you leave your car or van for more than a week
its a good idea to charge it. Or more accurately to "maintain" it in a
healthy fully charged state. Your battery will stay healthy longer.
Buy a battery optimiser or battery maintainer as soon as possible if this scenario sounds like
Your battery will love you and it will stay
healthy much longer. It doesn't actually need a full charge (although that wont
hurt) but it needs a maintenance charger like this Optimate at the top of the
connecting and leaving connected while you are not regularly using your car.
It may well still start
if you don't bother but your battery is suffering and will, sooner or
later, let you down. Another alternative is a good solar charger of 2 to 5
watts. It wont "charge" your battery but it will keep it topped up hopefully and
prevent it going flat and sulphating. Less than 2 watts is a complete waste
of time unless you live in Arizona! I leave a 5 watt one above plugged into the cigarette lighter socket
and sat on my
dashboard when I am not using my van. It keeps my battery fully charged up and
healthy if the vehicle is unused for long periods. of a week or more!
See larger image of the
Hawker Odyssey battery under test.
Here is an example:
Disabled adapted Rollx van. Has all kinds
of immobilisers, satellite navigation, engine management, alarm and an extra computer in the
boot to control the ramp/door/lowering etc. Here it is with the vehicle
all locked up and the engine stopped. After 30 mins. The Clamp Ammeter shows a
0.2 amp (200m/amp) drain on the battery. This is quite high but similar figures may
be typical for some other modified
vehicles of this kind. 20 to 50 m/amp is more normal.
It initially starts as 10 amps plus after switching off getting
out and locking the van! 10 Amps! But gradually all the various electronics go to
"sleep" and it settles at this relatively low value. The voltmeter shows the
brand new Hawker Odyssey battery is fully charged at 12.8v. Now 200ma at
12v is 2.4 watts. Or about 0.2 amps lost per hour while parked or 4.8 amps per
day. This looks abnormally high but it always seems to settle at that figure.
50ma is probably closer for most vehicles.
That means that in ten days time if I don't drive it or charge
it the battery will be 2/3rds drained! that's right 2/3rds!!! It will have
suffered some sulphation and had its service life shortened. It will also probably
still start the Van - Just! After two weeks? Doubtful if it would.
see why I use Optima or Hawker Odyssey batteries? They are both dual purpose
Deep Cycle and Starting Batteries. This way the slowly discharging battery
is much less damaged than an ordinary starter battery would be. Most modern vehicles are like this.
Have yours tested. A deep Cycle and Starter battery is often a much better
option in most modern vehicles, including standard non adapted ones.
All batteries HATE BEING DISCHARGED!
You may like to consider fitting a dual purpose STARTER & DEEP
CYCLE battery to a
mobility vehicle if it has extra equipment like a powered ramp or wheelchair
Because these are a special "breed" of battery that can both start a
car as well as being Deep Cycled like a powerchair or scooter battery.
So that all
those times when the battery gets a bit low due to the extra drain after the
engine is stopped will do much less damage to your battery.
Examples of these include the
Optima, Hawker Odyssey. and a few others.
Not cheap but being disabled seldom
is. And we need the security of a good battery more than anyone else.
powerchair and vehicle batteries
2. Charging a powerchair or scooter battery:
Powerchairs and Scooters use Deep Cycle Batteries. These, despite their name,
DO NOT LIKE BEING DISCHARGED! All lead based batteries hate it, but deep cycle
batteries suffer less damage when doing so.
With this in mind its best to ALWAYS charge them fully every
single night in a powerchair or scooter if used at all during the
day. And once a week even
if NOT used at all. With the manufacturers charger or something equivalent
with the correct charging profile for whatever batteries you have fitted.
A good Deep Cycle 3 or 4 stage logic controlled
charger (switch mode or transformer) designed for the type of battery that you use is essential. Even if you
only used your Power Chair or Scooter for ten minutes you must do a complete
night. Don't Forget. If you do and you continue to use it you will
discharge your batteries much deeper than needed and no lead based batteries really like
that. Regardless of what any "expert" may tell you!
REMEMBER!!! Charge weekly if you don't use it.
Nightly if you do use it. Overnight.
If you have not used your powerchair or scooter at all then charge it once
every week. Fully over night. Once a week will help prevent the batteries becoming
slightly discharged and internally sulphated which ultimately is what kills them,
if just left and allowed to become discharged. Never discharge Lead Acid Deep
Cycle batteries on purpose to get rid of any memory effect! They don't have a
memory! Even the original rumour that Ni-Cad batteries had a "memory"
that came from NASA was
not actually true in any normal use. All deep discharge does is damage your
wheelchairs batteries faster.
If you get chance during the day it IS BENEFICIAL
to plug in the charger to lower the average daily discharge level. This is
called opportunity charging. Or opportunistic charging. Contrary to what you may read elsewhere
by the less well informed it
beneficial. Anything that lowers the average discharge level each day helps your
batteries live longer. It still needs
the full overnight charge however every night just the same. The FULL charge
cycle doesn't just "charge" but it also equalises all the cells in
each battery bringing them all up to the same voltage level. So Plug it in for a
while if you get chance while sat at a computer for watching TV. But
also do the full overnight charge too. Opportunistic charging does NOT replace
Are you fed up with waiting hours for your chair or scooter to charge? Well
depending on your battery type you CAN fast charge them. I use Optima Deep Cycle
and Starting batteries (Yellow Top ones) or Hawker Odyssey AGM batteries partly because it allows me to charge them up in the
middle of the day up to a 95 percent full charge in around one hour. Go
from all but exhausted, to ready
to go again while you check your email... See
It still needs the full overnight
charge while you sleep from the normal slow 8 amp (or about 20 percent of battery capacity) charger
however every night just the same or your batteries never get properly equalised
and will become unbalanced.
Contrary to what you are told on certain other websites fast charging or
opportunity charging your deep
cycle batteries isn't harmful and can lower the average depth of discharge
meaning longer service life. But you do need to connect directly to the
batteries and not try to put extra current through the normal charging socket...
Normal overnight (slow) charger size? Its NOT at all critical unlike what
some so called experts would tell you. The sizes below will get your heavily
used scooter or powerchair fully charged and ready to go while you sleep.
Smaller wont hurt the batteries at all. Even a 1 amp multi stage charger will
safely charge your batteries. But it will take way too long!
3 amp for 25 amp hour batteries.
5 amp for 35 to 45 amp hour batteries.
7 to 8 amp for batteries 50 to 75 amp hour.
If you try to charge with a bigger charger
but still of the correct multi stage deep cycle type then several things can
(a) Depending on battery type you may have no problem at all. Your batteries
will just charge faster. These chargers are voltage controlled so even a big
charger will not hurt a good deep cycle battery unless it gets too hot. Too hot
means about 50 degrees centigrade. I charge mine regularly at 30 amps.
batteries (Optima) show no sign of stress and the manufacturers suggest that
there is no limit to the current at all. Not only is my 30 amp charger OK its
fine to use a 200 amp one. However charging faster
MAY shorten battery life if they get hot (50+ centigrade). But even at a 100 amp
rate they only get vaguely luke warm so its just not a problem.
b) If your batteries are less good quality you may find acid or gelled acid all over the
place! Check the manufacturers website for fast charge current limits. Optima's
for e.g. say no problem at all...
Sonnenschein I think too) also say its not a problem other than watch the
temperature. And after talking to the MK guys they also say no inrush current
limit is applicable.
So its safe to fast charge all of my batteries at least! And probably all the
c) don't ever put more than the standard chargers output (5 or 8 amps) through the
stock charging socket!
Connect your own cables and connector directly to the
Some Related Pages on this site:
batteries to buy
and why you need them
powerchair directly from a vehicle. via the same Anderson
Fast charge YOUR powerchair
in around 1 hour
Batteries for both vans, cars & power
batteries to buy
Lithium Ion batteries for
powerchairs & scooters
My power wheelchair or scooter will
BCI battery sizes, group 22, 24, 34, 27 etc
powerchair by radio control
superior powerchair overnight charger
How to organise yourself for every eventuality!
battery powered BM3 powerchair!
Questions, want to share?
flexible and useful Hyperion charger can charge any battery. Including
your wheelchair from your car or the other way around!