A trickle charger is designed to charge at a constant, low current.
In theory this current should exactly match the discharge rate of
the battery. In practice the designer has to compromise as they don't
know which battery will be connected or the temperature that it will be
stored at. In practice trickle chargers overcharge batteries slightly.
A float charger, e.g the Optimate, switches the charger off then measures
the battery voltage. If it's below 12.65, it supplies a small charging
current (trickle, ~0.2A) for a short period of time (30 minutes?)
then checks the voltage again and continues until the battery is fully
charged: 12.65V. From then on the voltage is monitored until it falls
below 12.65, whereupon another charge/measure cycle commences. It can
still overcharge the battery but for no more than the 30 minutes or so
of its charging cycle. The effect will be worst if you use it with a
very small battery (<10AH).
In fact the Optimate and it's siblings do more. If the battery is
connected with a voltage considerably lower (closer to 12.0V), then each
charging period is done at a higher current (~1.0A). They won't fast charge
a battery, but they will bring it up to a fully charged state rather
faster than if they only ever supplied a trickle.
Wikipedia suggests these voltages against charge state:
12.65V 100%
12.45V 75%
12.24V 50%
12.06V 25%
11.89V 0%
--
Jan
On the road:'03 ST4s ABS (since April), '99 M900 (since new)
Languishing: 2 'Guzzis
Norwich, UK
Alistair A, on Tue, Feb 01, 2011 at 03:16:16PM -0000 you wrote:
>
> Hi Nick
> With regards to battery discharging, I think this is down to concrete
> being more conductive than wood due to as you say being damper.
> What is the difference between a 'trickle' and 'float' charger and what
> make would you recommend?
> Kind Regards Al
> --- In [1]st2_owners@yahoogroups.com, "Nick Woods" <nickw@...> wrote:
> >
> >
> >
> > --- In [2]st2_owners@yahoogroups.com, Jan Wysocki <st@> wrote:
> > >
> > > Alistair,
> > > that's basically ok, but a lot of faff to go through. Ok, if you
> don't
> > > have better things to do with your time:) (But what can I say, I
> spent
> > > yesterday making marmalade instead of buying it.)
> >
> >
> > Oh good man! There's a tenner that says the marmalade made here at
> IP22 2JJ is tastier than any made in Norwich!! By the way, Carl has
> done a job on my ST4 (no cam/rocker wear in 30K miles) and I should get
> it back today.
> >
> > Anyway, Alistair; no way would your plan be worthwhile in my book,
> when application of a float charger on a periodical basis will keep the
> battery fine. I prefer not to hook the Optimate up longterm, partly
> because it's been suggested that batteries can boil dry, and mostly
> because I have too many batteries that need charging! Just a thought:
> the concept of the surface a battery sits on having an effect on
> self-discharge must surely relate to any film of moisture/condensation
> over it. A wood floor will be much warmer than a concrete one, after
> all.
> >
> > NickW, UK
> >
>
>
> References
>
> 1. mailto:st2_owners%40yahoogroups.com
> 2. mailto:st2_owners%40yahoogroups.com
> 3. mailto:orac1waterskiing@yahoo.co.uk?subject=Re%3A%20Hibernating%20batteries%20over%20Winter
> 4. mailto:st2_owners@yahoogroups.com?subject=Re%3A%20Hibernating%20batteries%20over%20Winter
> 5. http://groups.yahoo.com/group/st2_owners/post;_ylc=X3oDMTJyNTRuMHUzBF9TAzk3MzU5NzE0BGdycElkAzEwOTkxMjIEZ3Jwc3BJZAMxNzA1MTI2MjY0BG1zZ0lkAzExNjI1NARzZWMDZnRyBHNsawNycGx5BHN0aW1lAzEyOTY1NzMzNzk-?act=reply&messageNum=116254
> 6. http://groups.yahoo.com/group/st2_owners/post;_ylc=X3oDMTJlMHB1MDRsBF9TAzk3MzU5NzE0BGdycElkAzEwOTkxMjIEZ3Jwc3BJZAMxNzA1MTI2MjY0BHNlYwNmdHIEc2xrA250cGMEc3RpbWUDMTI5NjU3MzM3OQ--
> 7. http://groups.yahoo.com/group/st2_owners/message/116238;_ylc=X3oDMTM4NGhoYzRoBF9TAzk3MzU5NzE0BGdycElkAzEwOTkxMjIEZ3Jwc3BJZAMxNzA1MTI2MjY0BG1zZ0lkAzExNjI1NARzZWMDZnRyBHNsawN2dHBjBHN0aW1lAzEyOTY1NzMzNzkEdHBjSWQDMTE2MjM4
> 8. http://groups.yahoo.com/group/st2_owners/members;_ylc=X3oDMTJmM2ZuaXB2BF9TAzk3MzU5NzE0BGdycElkAzEwOTkxMjIEZ3Jwc3BJZAMxNzA1MTI2MjY0BHNlYwN2dGwEc2xrA3ZtYnJzBHN0aW1lAzEyOTY1NzMzNzk-?o=6
> 9. http://groups.yahoo.com/group/st2_owners/spnew;_ylc=X3oDMTJmdDFlY2ViBF9TAzk3MzU5NzE0BGdycElkAzEwOTkxMjIEZ3Jwc3BJZAMxNzA1MTI2MjY0BHNlYwN2dGwEc2xrA3ZwaG90BHN0aW1lAzEyOTY1NzMzNzk-
> 10. http://groups.yahoo.com/group/st2_owners;_ylc=X3oDMTJlY2hmNmVwBF9TAzk3MzU5NzE0BGdycElkAzEwOTkxMjIEZ3Jwc3BJZAMxNzA1MTI2MjY0BHNlYwN2dGwEc2xrA3ZnaHAEc3RpbWUDMTI5NjU3MzM3OQ--
> 11. http://groups.yahoo.com/;_ylc=X3oDMTJkNnFpbnQ4BF9TAzk3MzU5NzE0BGdycElkAzEwOTkxMjIEZ3Jwc3BJZAMxNzA1MTI2MjY0BHNlYwNmdHIEc2xrA2dmcARzdGltZQMxMjk2NTczMzc5
> 12. mailto:st2_owners-traditional@yahoogroups.com?subject=Change%20Delivery%20Format:%20Traditional
> 13. mailto:st2_owners-digest@yahoogroups.com?subject=Email%20Delivery:%20Digest
> 14. mailto:st2_owners-unsubscribe@yahoogroups.com?subject=Unsubscribe
> 15. http://docs.yahoo.com/info/terms/
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