Solar battery charger

[dickm]

My ancient ride-on mower/lawn tractor lives in a garden shed some distance from mains power. Does anyone have any experience of solar powered battery chargers which could be used to keep the battery topped up during longer layoffs? Yes, I know I can (and do) lug the battery to a charger, but I'm nearly 78 and nearly as knackered as the tractor!

 

[Droogs]

pm sent

 

[manicminer]

I have used one of these for my motorcycle for years. Although its not classed as waterproof, I have hung it on a fence and it has lived through some terrible downpours. I keep meaning to wrap a clear bag over it but havent got round to it.
Uses clips to attach to the battery.

 

[TRITON]

I'd also look towards the yachting and boating industries. Yachts ,especially long haul cruisers use solar power, and wind generators to keep the boat batteries topped up.
Sorry Ive no idea of ratings, but Ive seen a lot of cruising boats with wind vane generators, so perhaps one of those on the shed roof, coupled with solar power will keep it topped up all through the year.
https://www.lifeofsailing.com/post/best-wind-generators-for-sailboats

 

[gmgmgm]

They do work, and are fairly easily available - put "solar car battery charger" into Amazon/ebay to see some choices. They work for keeping it topped up, but don't have the power of a mains charger.

If it's frequently struggling (and you say it's an ancient lawn tractor) how old is the battery? They have a tough life in mowers, and batteries are fairly cheap. Whenever I replace one I think "why didn't I do this sooner?" as it starts so easily!

 

[littleplop]

I think the only issue with the amazon example above is the very low 1.8w output?

For just a couple of quid more there are 10w panels that will do the job potentially better:
amazon example

I don't know that particular product but as an example that is reasonable.

Also, you might be surprised at how well the panels work stuck behind the window of the shed if it has one - it will reduce output significantly for sure but if concerned about weather affecting it would probably be sufficent.

I'm not sure if I can do this? but I actually use marine panels for my boating projects and have access to marine grade 10, 20, 50 and 100w fixed solar panels (although the 10w panels are currently unavailable with no restock date unfortunately).

If interested please PM me and I can send you some details - but as an example the 20w panel is £30 inc delivery to mainland UK and is IP67 rated as it is designed for the marine environment. I can try to chase up any news on teh 10W as they are only £18 inc delivery.

I will delete the above if not allowed under forum rules but thought it might be useful.

 

[dickm]

For just a couple of quid more there are 10w panels that will do the job potentially better:
amazon example

Oh dear; you are straining my principles to the limit! I try to avoid Amazon like the plague it is, but that looks excellent value for the given spec.
In answer to gmgmgm, the tractor actually starts almost instantly when the battery is topped up (it's a 12hp Briggs engine, built like the proverbial tank). The battery is not in the first flush of youth, and as you say, they have a hard life. It's a "Lion" brand, which has already lasted much better than the Yuasa which it had before.
A passing gripe - the best price battery supplier is somewhere in Englandshire and won't shop north of Hadrians Wall.

 

[dickm]

I'd also look towards the yachting and boating industries. Yachts ,especially long haul cruisers use solar power, and wind generators to keep the boat batteries topped up.
Sorry Ive no idea of ratings, but Ive seen a lot of cruising boats with wind vane generators, so perhaps one of those on the shed roof, coupled with solar power will keep it topped up all through the year.

That's an interesting thought - the shed is under some trees, so is far from ideal for solar, but up here the wind is pretty reliable. Wonder what happened to the 12v Lucas Freelight one of the family had on their garage back in the 1950s?

 

[littleplop]

That's an interesting thought - the shed is under some trees, so is far from ideal for solar, but up here the wind is pretty reliable. Wonder what happened to the 12v Lucas Freelight one of the family had on their garage back in the 1950s?

I'm waiting on one of these WindLily turbines to be delivered (9 months and counting...) mainly because I just like dicking around with things, but it should be good for overnight keeping the 12v system up on my boat and I'm interested in what it will do dunked in the water at 20 knots behind the trimaran.

Probably explode.

Anyway, as long as your shed is well away from you and your neighbours wind could be worth a punt, but it is bloody noisy.

Also, anything much over this low level windliliy type turbine and you have to start thinking about how you dump excess energy, so you need to start thinking normally about a controller and cheap heatsink to dissipitate it from what I've seen in marine stuff, but never had any hands on with any yet.

All interesting? stuff though - I hope this Windlily thing actually turns up eventually as I got it cheap on KickStarter but dear god they are being slow in shipping them.

 

[John Brown]

It's worth checking the figures on output for solar cells from Amazon or eBay. A useful rule of thumb is 150 watts per square metre. A lot of stuff you see advertised quote wildly overthetoptimistic figures.

 

[Fergie 307]

I'm waiting on one of these WindLily turbines to be delivered (9 months and counting...) mainly because I just like dicking around with things, but it should be good for overnight keeping the 12v system up on my boat and I'm interested in what it will do dunked in the water at 20 knots behind the trimaran.

Probably explode.

Anyway, as long as your shed is well away from you and your neighbours wind could be worth a punt, but it is bloody noisy.

Also, anything much over this low level windliliy type turbine and you have to start thinking about how you dump excess energy, so you need to start thinking normally about a controller and cheap heatsink to dissipitate it from what I've seen in marine stuff, but never had any hands on with any yet.

All interesting? stuff though - I hope this Windlily thing actually turns up eventually as I got it cheap on KickStarter but dear god they are being slow in shipping them.

I agree, you need to have a controller otherwise you can easily overcharge the battery.

 

[Jameshow]

I would think wind would trump solar once past Hadrian's wall?!

 

[dickm]

I would think wind would trump solar once past Hadrian's wall?!

Strangely, that may not be completely true. Although we probably get lower intensity of sunlight, the longer hours in summer compared to Englandshire just about compensate. Recall comparing notes with a forum member in Southampton, and his annual generation was about the same as our's from solar panels on the roof.
Trouble with our wind resource where we are situated is it's a bit "all or nothing"