Posted by Jim Wilkins on June 22, 2011, 11:41 am
> >
> I can add a separate charge controller just for the mower battery in
> parallel with the regular charge controller. Would that be sufficient?
> The mower battery would not be in the same enclosure, so hydrogen
> shouldn't be a problem.-
If these are simple series charge controllers with diodes the lowest
voltage battery will hog the current since the higher voltage in the
other batteries will reverse-bias their controller diodes. I can't say
that it WILL work without checking in person with a meter. Some lawn
tractor batteries are very cheaply made and may require a higher than
normal charging voltage to force current into weaker cells.
http://www.carkb.com/Uwe/Forum.aspx/rvs/2411/Equalizing-charger-on-deep-cyc=
le-batteries
Do you invert your 12V to 120VAC? If so, a regular trickle charger
might be simpler overall, or take the battery home occasionally.
Here is an expensive example of a battery charger that runs off 12V:
http://www.powerstream.com/DCC.htm
They need to contain an inverter to raise the output voltage above
their input voltage.
If you can tinker with electronics these have a useful 12V - 12V DC
inverter:
http://cgi.ebay.com/ebaymotors/COLEMAN-POWERMATE-EMERGENCY-CAR-STARTER-12V-=
/390323871786
jsw
Posted by ...........Rob on June 25, 2011, 6:10 pm
> > I can add a separate charge controller just for the mower battery in
> > parallel with the regular charge controller. Would that be sufficient?
> > The mower battery would not be in the same enclosure, so hydrogen
> > shouldn't be a problem.-
> If these are simple series charge controllers with diodes the lowest
> voltage battery will hog the current since the higher voltage in the
> other batteries will reverse-bias their controller diodes. I can't say
> that it WILL work without checking in person with a meter. Some lawn
> tractor batteries are very cheaply made and may require a higher than
> normal charging voltage to force current into weaker cells.http://www.carkb.com/Uwe/Forum.aspx/rvs/2411/Equalizing-charger-on-de ...
> Do you invert your 12V to 120VAC? If so, a regular trickle charger
> might be simpler overall, or take the battery home occasionally.
> Here is an expensive example of a battery charger that runs off 12V:http://www.powerstream.com/DCC.htm
> They need to contain an inverter to raise the output voltage above
> their input voltage.
> If you can tinker with electronics these have a useful 12V - 12V DC
> inverter:http://cgi.ebay.com/ebaymotors/COLEMAN-POWERMATE-EMERGENCY-CAR-STARTE ...
> jsw
I have a 85W solar panel charging my battery operated lawn mower, runs
through a C12 charge controller. I also ran another controller (one of
those cheap on/off that comes with those 15w panel kits) off the same
85W panel to charge a small 12v sla battery (5 amp hour). Been
running two controllers off the same panel for about 2 years and have
had no problems.
$5 -$0, a little wire = problem solved.
Rob
Posted by Jim Wilkins on June 25, 2011, 10:35 pm
> > > I can add a separate charge controller just for the mower battery in
> > > parallel with the regular charge controller. Would that be sufficient?
> > > The mower battery would not be in the same enclosure, so hydrogen
> > > shouldn't be a problem.-
> > If these are simple series charge controllers with diodes the lowest
> > voltage battery will hog the current since the higher voltage in the
> > other batteries will reverse-bias their controller diodes. I can't say
> > that it WILL work without checking in person with a meter. Some lawn
> > tractor batteries are very cheaply made and may require a higher than
> > normal charging voltage to force current into weaker cells.http://www.carkb.com/Uwe/Forum.aspx/rvs/2411/Equalizing-charger-on-de ...
> > Do you invert your 12V to 120VAC? If so, a regular trickle charger
> > might be simpler overall, or take the battery home occasionally.
> > Here is an expensive example of a battery charger that runs off 12V:http://www.powerstream.com/DCC.htm
> > They need to contain an inverter to raise the output voltage above
> > their input voltage.
> > If you can tinker with electronics these have a useful 12V - 12V DC
> > inverter:http://cgi.ebay.com/ebaymotors/COLEMAN-POWERMATE-EMERGENCY-CAR-STARTE ...
> > jsw
> I have a 85W solar panel charging my battery operated lawn mower, runs
> through a C12 charge controller. I also ran another controller (one of
> those cheap on/off that comes with those 15w panel kits) off the same
> 85W panel to charge a small 12v sla battery (5 amp hour). Been
> running two controllers off the same panel for about 2 years and have
> had no problems.
> $5 -$0, a little wire = problem solved.
> Rob-
The OP wrote:
"My weekend cabin has:
42 watt Kyocera panel
2 100 amp hour Power Sonic Sealed Lead Acid Batteries
1 Morningstar Charge controller Sunsaver 10
I have just been given a riding mower that has a 12 volt battery that
I
may need to charge from time to time. "
If the batteries are left on charge between weekends they should all
fully charge, or overcharge. My comments were directed toward
discovering a low battery on Saturday morning and trying to charge it
while powering everything else.
jsw
Posted by clare on June 22, 2011, 12:32 am
wrote:
>DLC wrote:
>> My weekend cabin has:
>>
>> 42 watt Kyocera panel
>> 2 100 amp hour Power Sonic Sealed Lead Acid Batteries
>> 1 Morningstar Charge controller Sunsaver 10
>>
>> I have just been given a riding mower that has a 12 volt battery that I
>> may need to charge from time to time.
>>
>> Would there be any problem with temporarily connecting this battery in
>> parallel with the solar system batteries?
>Yes. Current flow could be a huge issue.
>Suggest connect a battery charge controller to tailor the
>charge current so that you don't damage your system.
>Outgassing hydrogen and sparks mix *all too well*.
>--Winston
Depends a lot on how big the tractor battery is. Most are about 35 Ah
- so a 42 watt charger, capable of producing NO MORE than 3.5 amps,
will NOT have any danger of harming the battery due to too high a
charging current.
At 14.2 volts, which is the peak charging voltage of a 12 volt battery
(or very close) that is only just a hair under 3 amps.
No Problemo.
Posted by DLC on June 26, 2011, 3:20 pm
On 6/21/2011 3:41 PM, DLC wrote:
> My weekend cabin has:
> 42 watt Kyocera panel
> 2 100 amp hour Power Sonic Sealed Lead Acid Batteries
> 1 Morningstar Charge controller Sunsaver 10
> I have just been given a riding mower that has a 12 volt battery that I
> may need to charge from time to time.
> Would there be any problem with temporarily connecting this battery in
> parallel with the solar system batteries?
> I do have a generator that I could use, but it seems a waste of fuel to
> use it to charge this small battery.
> Thanks
I thank everyone for their suggestions. I now know several approaches
NOT to use.
I am now considering a 5 watt 12 volt solar panel dedicated to keeping a
charge on the mower battery.
If the battery is seriously discharged, I can still fire up the generator.
> I can add a separate charge controller just for the mower battery in
> parallel with the regular charge controller. Would that be sufficient?
> The mower battery would not be in the same enclosure, so hydrogen
> shouldn't be a problem.-