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bldginsp
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# Posted: 16 Mar 2016 01:58pm
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I got a tractor and put it on my property, I'm in the process of fixing it up. But it's just going to sit most of the time, for months at a time, and I want to keep the 12v battery charged. I've done a little research but I'd like input from those with experience.
The shed that the tractor will collect dust in is in trees and won't get 6 hours of unshaded sunlight, in winter less than summer. The thin film amorphous silicon panels, supposedly, still produce power in partial shade/cloudy conditions. Anyone experienced with these?
I guess I should have a charge controller to prolong battery life and prevent overcharging. I read that at 5 watts and below, you don't need a charge controller, but a 5 watt panel is just barely enough, if at all, for maintaining a battery.
Here's what seemed like a good description of different alternatives:
http://www.carbatterychargerscentral.com/12-volt-battery-charger-top-5-solar/
Based on that, here's what I'm looking at- Sunforce 15 watt amorphous panel charging system with charge controller.
http://www.amazon.com/Sunforce-50033-15-Watt-Solar-Charging/dp/B001RJOP5Y%3FSubscript ionId%3DAKIAJRETYCELXP2DI45A%26tag%3Dcarbattcharce-20%26linkCode%3Dxm2%26camp%3D2025% 26creative%3D165953%26creativeASIN%3DB001RJOP5Y
Those Amazon links are insane!
The Sunforce is about 70-80 bucks, made in China, and apparently have a good reputation.
Here's another alternative- made by VDC in US, about $150 but apparently very high quality manufacturing and good battery maintenance circuitry design.
http://www.amazon.com/BatteryMINDer-Solar-Charging-System-SCC-015/dp/B000JS268M?tag=b estrefrigecentral-20&linkCode=pip&linkId=73582d17-232b-49d0-aae8-8a87242f5bb1
Anyone have experience with maintaining a battery for months at a time off grid?
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Steve_S
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# Posted: 16 Mar 2016 02:42pm
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I bought one of these Coleman-40W-12V-Crystalline-Solar-Panel-with-Stand 3 years ago to use on my vehicles, leaving in the windshield when needed. Back then I think I paid $90 for it. Works a treat and never ever had issues.... This is the Amorphous Panel which even in overcast light still generates the juice. My PT-Cruiser has a power drain I never could find, so....
Is there better & cheaper out there today ? Possibly BUT for a 40Watt Panel that makes go go juice even in low light, pretty hard to beat IMO.
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MtnDon
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# Posted: 16 Mar 2016 03:34pm
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We used a couple of 15 watt thin film panels with a cheap CC when we had an RV with 4 golf cart coach batteries. That kept the batteries fully charged even though the panels had lots of moving shade through the day. Worked through the 4 to 5 month winter when we could not access the property.
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SE Ohio
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# Posted: 16 Mar 2016 04:42pm
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My concern is that if the flooded lead acid battery sits and doesn't get the "boiling" charge (think good solar controller) then plates can still get sulfation which will lead (no pun) to early battery death. Our cars/trucks don't need this function because the batteries get shaken a bit when we drive, rinsing the plates and preventing buildup.
A good solar charge controller will overcharge the battery, boiling it a bit to break down the sulfation. I think I remember reading that there is a nominal amperage needed to accomplish this with sufficient amperage, maybe 6 amps? Might have read that on this forum Don't know if low end controller will perform this function or if 30 watts will be enough? 30w of panels/12v of battery is less than 3 amps, not near 6.
My motorcycle and battery would sit all winter while getting a charge, yet the battery wasn't reliable past 2 years. In hindsight, I shoulda let the battery get jostled around in my car's trunk between charges.
Your mileage may vary...
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bldginsp
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# Posted: 16 Mar 2016 06:33pm - Edited by: bldginsp
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Makers of the VDC charger claim that their 15 watt charger has some kind of pulse action that prevents or reduces sulfation. But this battery wil definitely sit motionless for extended periods. But come to think of it, so do all the batteries in off-grid solar powered situations. But they are charging at well over 6 amps.
Hadn't heard about this 6 amp threshold. Let me know if you learn more.
Thanks all for the input.
If I'm going to spend a significant amount of money on a solar charger, I want to be pretty sure it's going to pay for itself with extended battery life, so I don't have to lug the **** battery around to charge it at home....
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MtnDon
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# Posted: 16 Mar 2016 06:42pm
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Quoting: SE Ohio ...concern is that if the flooded lead acid battery sits and doesn't get the "boiling" charge (think good solar controller) then plates can still get sulfation which will lead (no pun) to early battery death.
There is some truth in that but also some misunderstanding, IMO.
First, what exactly causes a lead acid battery to sulfate? Here are two references on that. The first reference is from Rolls a battery manufacturer, the second from batteryuniversity.com. Rolls might want to sell you batteries but once they have you as a customer they want to keep you happy. BatteryU is just info, they have nothing to sell you. I trust their info, in other words.
One quote from Rolls: (Italicized text is my emphassis.) "Causes of battery sulfation: Batteries sit too long between charges. " another... "Battery is stored without some type of energy input.". A quote from batteryU... "
Sulfation occurs when a lead acid battery is deprived of a full charge.". The common theme is that sulfation occurs when a battery is stored at less than 100% full charge.
There are other causes of sulfation such as continuous cycling without ever reaching a full charge but for this question we are assuming the battery will be fully charged when the tractor is parked. If the battery is not fully charged when parked that is a good argument for having a larger than needed solar panel with a charge controller that has the three stages of bulk, absorb and float. We also must assume that the battery is in good condition, that it does not already have some problems because of mistreatment.
A charger of any kind that applies a float charge to maintain an already 100% charged battery without being too high a voltage to cause water loss can maintain a battery in excellent condition without any cycling or any need to cause bubbling, or "boiling" in the cells.
Now, to address what I see as a misunderstanding. It is true that off grid batteries can develop problems with sulfation if they are charged at too low a charge rate, when the low charge rate is an everyday occurance. That is one reason that the "magic" figure of a rate of charge equal to 10 to 13% of the amp-hour capacity is recommended. That rate will cause bubbling of the electrolyte and that promotes mixing of the electrolyte, but not too much bubbling that can be detrimental to plate longevity. Without this bubbling, or the motion induced mixing when an automobile moves down the road, it is possible for the electrolyte to stratify; for more dense electrolyte to settle to the lower regions of the cells. This is more pronounced or more likely with tall case batteries like L-16's than it is with auto or golf cart sized batteries. An occasional equalization charge to the off grid batteries helps as the excessive bubbling action that occurs stirs up the electrolyte.
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bldginsp
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# Posted: 16 Mar 2016 08:03pm
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So clearly maintaining charge is key to longevity. Some chargers have some kind of anti- sulphate cycle, perhaps the "boiling charge" that SE Ohio mentioned. Also, there are products on the market that you add to the battery which supposedly reduce sulphate formation and remove limited amounts of sulphate. But I saw one quote that basically said the best thing to do is avoid sulphate formation to begin with by maintaining charge.
If an adequate charge is maintained with enough bubbling to promote electrolyte mixing, but not so much as to promote water loss, would you still not have gradual water loss over time? If it is gassing it is losing hydrogen, which must come from water.
I don't see an amp hour rating on my battery, just CA 550 and CCA 450, or thereabouts. This is a 6 volt battery that I intend to replace with a 12 as I make a 12 volt conversion on the tractor. So anyway- can you calc amp hour rating from CA or CCA to determine if the charger is within the 10-13%?
One other thing- I measured voltage across each cell in this battery- one comes up well under 2 volts, the others over 2, the whole thing is well over 6 at full charge. Is the one lower cell the kiss of death for this battery?
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hamish
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# Posted: 16 Mar 2016 08:53pm
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For a starting battery, your going to have a very hard time finding a decent 6V battery these days. I have been fighting the 6V 8N blues for almost 10 years, before I converted to 12V. Even with year round weekly use I had yet to have a 6v starting battery last more than 2 years. Spend the money and do the 12v conversion, it pays for itself in the longterm.
Park it on a hill so you can bump start it till you convert it to 12v!
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MtnDon
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# Posted: 16 Mar 2016 09:06pm
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Quoting: bldginsp So anyway- can you calc amp hour rating from CA or CCA
No. No amp-hour rating is the hallmark of a craking battery.
Quoting: bldginsp anti- sulphate cycle, perhaps the "boiling charge" that SE Ohio mentioned. Also, there are products on the market that you add to the battery which supposedly reduce sulphate
For a battery that is maintained properly you don't need the snake oil... just an opinion.
Quoting: bldginsp If an adequate charge is maintained with enough bubbling to promote electrolyte mixing, but not so much as to promote water loss, would you still not have gradual water loss over time?
If the battery is being used, you want a charge that will promote bubbling. If the battery is sitting there on float (some call trickle) the bubbling is minimal as the battery is maintained at full charge. Some slight water use over months time when the battery is healthy.
With the old RV I did the same as I now do when leaving the cabin batteries over the winter. That is, be sure the electrolyte level is topped up and the battery at full charge when leaving them for a time of no use. Four or five months later I might need to add some water to bring the level back up. Even then the plates have had lots of fluid over the plates. Monitor your system until you get a feel for it.
If one cell is well under 2 volts and the others over, it is likely on its last legs. Good thing you are planning on a 12 volt conversion. Start with a new battery and you should be good for years if you maintain a good float on it. Good means a charger that does not over-volt to waste water but is high enough to maintain full charge. A hydrometer is your friend when working with flooded batteries.
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rockmtn
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# Posted: 16 Mar 2016 09:32pm
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a small (10-20 watt) panel with a maximum power point around 13-14 volts should totally cover you and be very inexpensive. You want intermittent trickle charging if the goal is to keep the battery topped off. and intermittent sun light will give you this. I wouldn't over think it by combining a CC. Sometimes the best systems are those at the absolute simplest.
Car batteries (e.g. whats in your tractor) are designed to handle this sort of charging profile (they don't like to be deep discharged, prefer a starting load, and then an ongoing charge till shut off). Off grid batteries (e.g Trojan tall cells) require a charge control to manage things like the need to bubble, balance cells, etc.
my 2 cents, based on running a few 12 V systems like this in my woods (solar panel tied directly to 12 V car battery)
Good luck!
E
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old243
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# Posted: 18 Mar 2016 10:47am
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I have a 5 watt coleman , hooked up to the battery , of my fork lift tractor, when sitting for long periods. Others on my sawmill and my mini hoe. Have been using them for several years. Seem to keep the batteries happy. old243
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bldginsp
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# Posted: 18 Mar 2016 04:18pm - Edited by: bldginsp
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Thanks old. I've read different things about the 5 watt, some people are real happy with them. I think in ideal conditions with lots of sun and a healthy, fully charged battery to begin with the 5 watt do a fine job of maintaining a battery. But they won't charge one that's seriously down as well, and in lower light conditions (like I have) they aren't quite adequate.
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old243
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# Posted: 18 Mar 2016 10:45pm
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If your tractor is in a shed where you won't get enough light to power a solar panel. Would you be better to remove the battery , take it inside for the winter, put your small solar panel inside a sunny window, and hook the battery up. I have 2 large batteries hooked up, to a 40 watt panel with a charge controller . They are in my workshop , which is not heated. Will reinstall them in the spring.old243
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bldginsp
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# Posted: 18 Mar 2016 11:36pm
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I'm trying to avoid removing the battery. They get heavier every year.
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MtnDon
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# Posted: 18 Mar 2016 11:43pm
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I agree, hauling batteries is to be avoided. I hate acid holes in my clothes.
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neckless
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# Posted: 20 Mar 2016 08:40am
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i have a 5 watt ion my pump battery works to keep battery charge all summer... just a sink and a shower that is used for two people
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