Forums

solar panel on sealed lead acid battery

Started by Fibo September 12, 2014
Hello,

I was wondering if anyone had any experience with using a solar power "maintainer" on a sealed lead acid battery?

I have this battery

http://expertpower.hostedbywebstore.com/12v-7Ah-SLA-Rechargeable-Battery/dp/B003S1RQ2S

and was thinking about buying this Solar Battery Maintainer to keep it charged

http://www.sunforceproducts.com/product_details.php?PRODUCT_ID=248

the battery will be powering a beaglebone and a small 20W class-d amplifier, in a portable application.

The manual for the solar cell, says don't keep it cell hooked up while using the battery, but I'm not sure why not?

Thanks!
On 9/12/2014 7:28 PM, Fibo wrote:
> Hello, > > I was wondering if anyone had any experience with using a solar power "maintainer" on a sealed lead acid battery? > > I have this battery > > http://expertpower.hostedbywebstore.com/12v-7Ah-SLA-Rechargeable-Battery/dp/B003S1RQ2S > > and was thinking about buying this Solar Battery Maintainer to keep it charged > > http://www.sunforceproducts.com/product_details.php?PRODUCT_ID=248 > > the battery will be powering a beaglebone and a small 20W class-d amplifier, in a portable application. > > The manual for the solar cell, says don't keep it cell hooked up while using the battery, but I'm not sure why not? > > Thanks! >
The manual is rather vague. I expect it has to do with liability if you stick it in your window while you drive. There are a zillion issues here. Claims to have IC to protect against overcharge. Depending on how much money they spent on protection, starting your car with it attached may break it. There are HORRIBLE voltage spikes in an automobile environment. For your application, it probably doesn't matter, unless their IC is insufficient to handle its power dissipation with full sun and minimum battery voltage under load. A bad design might go into limit-cycle oscillation. Bad designs do exist. Depending on where you live and the insolation numbers there, you won't get much out of this. Certainly won't run your 20W amplifier for long. You're gonna have to have half a watt of average power consumption to make this work in a very sunny location. Gets horribly worse if you have a week of overcast. Consider weather and your power budget very carefully.
On 2014-09-13, Fibo <panfilero@gmail.com> wrote:
> Hello, > > I was wondering if anyone had any experience with using a solar power "maintainer" on a sealed lead acid battery? > > I have this battery > > http://expertpower.hostedbywebstore.com/12v-7Ah-SLA-Rechargeable-Battery/dp/B003S1RQ2S > > and was thinking about buying this Solar Battery Maintainer to keep it charged > > http://www.sunforceproducts.com/product_details.php?PRODUCT_ID=248 > > the battery will be powering a beaglebone and a small 20W class-d amplifier, in a portable application. > > The manual for the solar cell, says don't keep it cell hooked up while using the battery, but I'm not sure why not?
electrically a solar cell battery a series string of low quality diodes pointed the wrong way. A "load dump" could fry it. If you're not running an altenator to charge the battery you're probably safe.
> Thanks!
-- umop apisdn --- news://freenews.netfront.net/ - complaints: news@netfront.net ---
> > The manual for the solar cell, says don't keep it cell hooked up while using the battery, but I'm not sure why not? > > electrically a solar cell battery a series string of low quality diodes pointed the wrong way. A "load dump" could fry it. If you're not running an altenator to charge the battery you're probably safe.
Are you saying that they don't even have a nickel or dime "blocking diode" to protect the panels?
In article <lv0cas$i58$1@dont-email.me>, mike <ham789@netzero.net> 
wrote:

> On 9/12/2014 7:28 PM, Fibo wrote: > > Hello, > > > > I was wondering if anyone had any experience with using a solar power > > "maintainer" on a sealed lead acid battery? > > > > I have this battery > > > > http://expertpower.hostedbywebstore.com/12v-7Ah-SLA-Rechargeable-Battery/dp/ > > B003S1RQ2S > > > > and was thinking about buying this Solar Battery Maintainer to keep it > > charged > > > > http://www.sunforceproducts.com/product_details.php?PRODUCT_ID=248 > > > > the battery will be powering a beaglebone and a small 20W class-d > > amplifier, in a portable application. > > > > The manual for the solar cell, says don't keep it cell hooked up while > > using the battery, but I'm not sure why not? > > > > Thanks! > > > The manual is rather vague. > I expect it has to do with liability if you stick it in your window > while you drive. > > There are a zillion issues here. > > Claims to have IC to protect against overcharge. > Depending on how much money they spent on protection, starting > your car with it attached may break it. There are HORRIBLE voltage > spikes in an automobile environment.
I suspect that's it. Depending on where the wires run, starting the car can create a 100V p-p spikes. I've seen brake lights create 40V spikes.
> > For your application, it probably doesn't matter, unless their IC is > insufficient to handle its power dissipation with full sun and minimum > battery voltage under load. A bad design might go into limit-cycle > oscillation. Bad designs do exist. > > Depending on where you live and the insolation numbers there, you won't > get much out of this. Certainly won't run your 20W amplifier for long. > You're gonna have to have half a watt of average power consumption to make > this work in a very sunny location. Gets horribly worse if you have > a week of overcast. > > Consider weather and your power budget very carefully.
-- I will not see posts from astraweb, theremailer, dizum, or google because they host Usenet flooders.
On 9/12/2014 11:31 PM, Jasen Betts wrote:
> On 2014-09-13, Fibo <panfilero@gmail.com> wrote: >> Hello, >> >> I was wondering if anyone had any experience with using a solar power "maintainer" on a sealed lead acid battery? >> >> I have this battery >> >> http://expertpower.hostedbywebstore.com/12v-7Ah-SLA-Rechargeable-Battery/dp/B003S1RQ2S >> >> and was thinking about buying this Solar Battery Maintainer to keep it charged >> >> http://www.sunforceproducts.com/product_details.php?PRODUCT_ID=248 >> >> the battery will be powering a beaglebone and a small 20W class-d amplifier, in a portable application. >> >> The manual for the solar cell, says don't keep it cell hooked up while using the battery, but I'm not sure why not? > > electrically a solar cell battery a series string of low quality > diodes pointed the wrong way. A "load dump" could fry it. If > you're not running an altenator to charge the battery you're > probably safe.
Or just put a diode in series with the solar collector. I think the unit listed above says it has one, no? -- Rick
mike wrote:
> On 9/12/2014 7:28 PM, Fibo wrote: >> Hello, >> >> I was wondering if anyone had any experience with using a solar power >> "maintainer" on a sealed lead acid battery? >> >> I have this battery >> >> http://expertpower.hostedbywebstore.com/12v-7Ah-SLA-Rechargeable-Battery/dp/B003S1RQ2S >> >> >> and was thinking about buying this Solar Battery Maintainer to keep it >> charged >> >> http://www.sunforceproducts.com/product_details.php?PRODUCT_ID=248 >> >> the battery will be powering a beaglebone and a small 20W class-d >> amplifier, in a portable application. >> >> The manual for the solar cell, says don't keep it cell hooked up while >> using the battery, but I'm not sure why not? >> >> Thanks! >> > The manual is rather vague. > I expect it has to do with liability if you stick it in your window > while you drive. > > There are a zillion issues here. > > Claims to have IC to protect against overcharge. > Depending on how much money they spent on protection, starting > your car with it attached may break it. There are HORRIBLE voltage > spikes in an automobile environment. > > > For your application, it probably doesn't matter, unless their IC is > insufficient to handle its power dissipation with full sun and minimum > battery voltage under load. A bad design might go into limit-cycle > oscillation. Bad designs do exist. > > Depending on where you live and the insolation numbers there, you won't > get much out of this. Certainly won't run your 20W amplifier for long. > You're gonna have to have half a watt of average power consumption to make > this work in a very sunny location. Gets horribly worse if you have > a week of overcast. > > Consider weather and your power budget very carefully.
But...but...did you not know that SOLAR POWER is _the_ solution for GW and will solve all of the power problems for humanity? How dare you!
On a sunny day (Fri, 12 Sep 2014 19:28:28 -0700 (PDT)) it happened Fibo
<panfilero@gmail.com> wrote in
<3b269bc4-7d12-4200-8b06-a777d4534c1d@googlegroups.com>:

>Hello, > >I was wondering if anyone had any experience with using a solar power "maintainer" on a sealed lead acid battery? > >I have this battery > >http://expertpower.hostedbywebstore.com/12v-7Ah-SLA-Rechargeable-Battery/dp/B003S1RQ2S > >and was thinking about buying this Solar Battery Maintainer to keep it charged > >http://www.sunforceproducts.com/product_details.php?PRODUCT_ID=248
Seems a toy.
>the battery will be powering a beaglebone and a small 20W class-d amplifier, in a portable application. > >The manual for the solar cell, says don't keep it cell hooked up while using the battery, but I'm not sure why not?
Maybe because of back EMF from things on your battery (motors etc).
>Thanks!
I am using a BIG solar panel to keep a sealed lead acid charged. I use a simple current and voltage regulated converter from ebay. The issue with those batteries is: READ THE BATTERY DATA SHEET, it will tell you what the charge curve should look like, usually a maximum voltage limit is mentioned [1]. You can - or cannot use current limiting, depends how much current your solar panel can supply, how fast you want to charge, etc. There are charge controllers that go for maximum possible power from the panels, but in my case you HAVE to stop at some voltage anyways. [1] If you do not voltage limit, then the 'open' voltage of a solar panel is way up there... and will kill the battery. Lead acid batteries (sealed or not) will die anyways after some years, and / or some number of full discharge cycles. But this thing in your link will only output 2.5 W at 12 V say 200 mA in the BRIGHTEST sunlight. So that battery will be empty anyway in a few hours with a few watt or a 20 W load. It cannot charge at night ... So if you live in the Sahara desert, and only use power at night, OK, maybe then it could keep your battery up.
On 2014-09-13, edward.ming.lee@gmail.com <edward.ming.lee@gmail.com> wrote:
>> > The manual for the solar cell, says don't keep it cell hooked up while using the battery, but I'm not sure why not? >> >> electrically a solar cell battery a series string of low quality diodes pointed the wrong way. A "load dump" could fry it. If you're not running an altenator to charge the battery you're probably safe. > > Are you saying that they don't even have a nickel or dime "blocking diode" to protect the panels?
If present it's probably a 50V (or lower) part, but it turns out there's a regulato chip too, that's probably even more fragile. -- umop apisdn --- news://freenews.netfront.net/ - complaints: news@netfront.net ---
On Saturday, September 13, 2014 1:59:18 AM UTC-7, Jasen Betts wrote:
> On 2014-09-13, edward.ming.lee@gmail.com <edward.ming.lee@gmail.com> wrote: > > >> > The manual for the solar cell, says don't keep it cell hooked up while using the battery, but I'm not sure why not? > > >> electrically a solar cell battery a series string of low quality diodes pointed the wrong way. A "load dump" could fry it. If you're not running an altenator to charge the battery you're probably safe. > > > Are you saying that they don't even have a nickel or dime "blocking diode" to protect the panels? > > If present it's probably a 50V (or lower) part, but it turns out there's a regulator chip too, that's probably even more fragile.
You can add a 1000V 1A diode for less than a quarter: http://www.digikey.com/product-detail/en/1N4007/1N4007FSCT-ND/965481