solar

[LegendLength]

so where do you get your batts? easy yes- cheap? my sla's were $60 each delivered

HobbyKing is the only good place: http://www.hobbyking.com/hobbyking/store/__7639__ZIPPY_Flightmax_5000mAh_6S1P_15C_.html .

I think you'll find them cheaper than SLA and of course lighter. Deliver is a bit cheaper too because of the weight. But charging etc. is different and you have to buy a special charge (couple o hundred bucks).

The trade off is twice the physical size of a flex panel vs. twice the weight for a mono or ploy 'classic' panel

Ohh didn't realize it was that bad. Do you have rough numbers for pricing, like per square meter and per watt? Just to save me looking it up I also thought the weight was much less than half for the thin panels but i've never actually checked.

 

[dmould66]

thanks for the link to hobbyking- only thing that worries me is they are rated in mah- millionamphere hour right? ive got two 20 a/h batts at the moment, this gives me a very good range,so how many would i need to keep the same range? with the charger-its looking a bit pricey?

 

[LegendLength]

I may have rushed in a bit quick to suggest Lipo, I assumed you were planning to do all-day touring on the bike rather than 10 mile journeys.

I'm guessing your 20 amp hour batteries are 12 volt correct? If so that would be a total of 240 watt hours. Each of those lipo bricks are 100 watt hours each and they're 24 volt. You can get the same batteries but half size so that they're 12 V and 50 Wh.

I currently use 6 of those 100 Wh bricks in my ebike build and the weight is 4.5 kg / 9 lbs. It gives me 600 Wh of usage (about 30 km with pedaling off-road).

But i think it all depends on your budget, your goals and how much time you have to tinker. With the lipo you have to be careful with charging and even discharging (e.g. going below a certain voltage will cause fire when they are next charged). That can all be done cheaply and easily but the procedures must be followed correctly or else.

If you already have lead acid and only plan to ride that short route I'd forget everything I said about using Lipo. I'm just interested in the solar thing because I had enough money I'd try to build a lightweight solar setup. Dubbo's a perfect place for solar so you've got that going for you!

I bookmarked a site last year for a company in WA that does solar ebike / trike stuff. If you like i'll try to dig it up. They had a lot of info on tests they had run, I think it's partly run by a university out there.

 

[dmould66]

yes cheers i would appreciate the link to the solar stuff

as to ten miles- ive not measured it accurately yet- but i recon with plenty of pedaling i get a lot more than that - even heavily loaded with trailer kids etc. thats the reason im not to bothered about the weight if i leave them behind i loose about 40k's from my set up.

finicky charging sounds like a problem on an extented trip,i truly think strong,dependable and easy to replace beats high teck light stuff on any trip

still getting my trike set up how i whant it after changing frames to full suspension last week-when i get that sorted ill get the panel on and let you know how it goes

 

[LegendLength]

This is the link: http://www.solarbike.com.au/solar_module.php , although I thought there was a bit more research on their site. I may have been looking at some other research sites at the same time and got them confused. The site seems more of just a hardware sales site although there is a little bit of info on solar there.

Good luck with the build whichever way you go.

 

[ddk]

Do you have rough numbers for pricing, like per square meter and per watt? Just to save me looking it up I also thought the weight was much less than half for the thin panels but i've never actually checked.

living stateside I dunno
the usa was blessed (or cursed depending on one's point of view) by having the chinese solar manufacturers dumping tons of solar panels here.
The immediate effect was depressed pricing on solar panels.
Here I can purchase a (single) 240 watt noncrystalline panel for $360... that's less than half the price of a couple of years ago.
The flex panels I've priced have been around 1600-$1800 for 200 watts ... ouch.

I thought flex panels should be cheaper since manufacturing costs are so minimal, but whatever...

of course one thing is quantity.
Solar panels ARE cheaper by the (more then) dozen.

If op was aI little more electronically-inclined and was comfortable soldering I would also suggest a "build it yourself" approach as (in the states anyway) a number of solar panel manufacturers have gone out of business and there seems to a flood of individual panels available at around 200-$300 per kilowatt (on ebay, for instance)

note- although I have many (many many) years of soldering experience I would be hesitant to assemble a large panel because of the shear boredom of endless soldering tabs up.

kinda like building a 72V 20 A/H battery pack... wouldn't do it- my time ain't worth much but it's worth more than drudge work will ever be.

@ op:>LiPo batteries are great compared to SLA batteries as in:

higher energy density
+you can safely use up to 80% of the battery's capacity without destroying the battery

strangely enough, from Hobby King (and other sources) LiPos are cheaper than SLA batteries
( for op's edification a 5000mA/h battery LiPo battery is 5 A/h and is about equivalent to a 10A/h SLA battery for range)

the battery chargers can be purchased for 30-$80 and conveniently are powered by 12V DC- well, convenient for me as my solar system is based upon 12V batteries allowing me to say (for bragging purposes mainly) my trike batteries are solar- charged. :lol:
-The real reason I use the solar system is because the 12V power outlet closest to my charging station is fed from one of the solar-charged battery banks :lol:

..and the worst part about LiPo batteries is they WILL catch fire if overcharges or drained to a voltage.
SLAs are far more tolerant of charge/discharge mistreatment inasmuch they won't set any forest fires under most conditions.

 

[ddk]

today I hooked the HK charger directly to my solar panels and successfully charged LiPos



I have these chargers

just a side note

 

[dmould66]

so 5000m a/h would be the equivalent of what ive got now- if the charger is 12v does this mean i would hook this up direct to the panel?
i dont know this gets more complicated the more i look at it-what ive got now works and i sort of understand it/ it dosnt present a serious fire risk- the distances i get are respectable and the loads i carry are verging on huge (read bales of straw,timber,animal feed and steel,) i figure if i stick with sla-double the a/h and add a panel it would go for longer than me-only time will tell-just whent up the state forest and measured a practice route,28ks mix of gravel sealed roads- im confident my current rig will make this fully loaded trailer the lot,if it does -ok ill continue