Barbie electric jeep

[halfcrazy]

Ok my daughter has a barbie jeep that has a 9.5 AH battery that is a SLA type. what i want to do is either mount a solar panel on the hood of it or put one on the playhouse with a plug so she can park it in the daytime when she isnt here and it will get some charge. 2 questions what size panel would anyone recomend and wouldnt i be smart to put a small charge controller in and what does everyone recomend? would the solar panel and charge controller live better not on her mobile jeep? and if so i may go a bigger panel and put a battery in the playhouse for a few lights and charging the jeep batteries.

[richhagen]

I had thought about something similar for an electric go cart, but never built it.  Ok, first, what voltage is the battery pack at?  If it is 12 volts, a small 10 watt panel would be plenty for a 9.5 amp hour pack to keep it charged when used occasionally.  You will need a charge controller suitable for sealed batteries, many have adjustments.  Sealed batteries are not tolerant to long term over charging.  They will be damaged.  I like the old Trace C-12's but that is probably overkill for your purposes.  Mounting them on the vehicle is convenient, however you have to weigh this against the possibility of damage to the panel during operation of the vehicle, not to mention the asthetics.  Best of Luck.  Rich

[juiced]

i love the idea. lets market it.

  Its a great way for kids to get a "homebrew" off-grid attitude. They grow up expecting free power, and also know how to produced it... excellant!

[wooferhound]

I've always wondered if one of those motors from those kids carts could be used to generate any decent power. they cog very noticably.. I see them out in the garbage all the time beside the road.

[halfcrazy]

Alright the battery is 12 volt and part of the reason i wanted the panel on the jeep was for astetics we are completely off grid and my 4 year old daughter is awsume with it turns stuff off behind people and what not i will post pics when i get it done.

[drdongle]

IPC has a 5 watt panel that is sold for charging car batteries, it runs about $30 at Northern supply. It would probably do what you need.

Carpe Vigor

Dr.D

[Norm]

  Yes they do cog pretty good but they have too few windings and too heavy of a guage wire ...3 pole armature etc. designed closer to being a starter motor than a generator....just my opinion

from past experience but I may not know what I'm talking about...like Rodney...I get no respect...LOL

              ( :>) Norm.

[John II]

Please remember the size of the pannel is totally dependent on how much she drives it. The more often she drives it, the larger a pannel you will need.

John II

[drdongle]

Very true, look at it as an opertunity to teach energy ecenomics.

Carpe Vigor

Dr.D

[halfcrazy]

Ok upon further diiging looks like the pv panel would be a little large for the hood of the jeep. So here is what we are planning now we are building a 12ft by 8ft 2 story play house for the 2 girls. We will put a few lights inside and a porch light on it and also our 12 volt flojet rain water pump for watering lawn and garden. We will put a small maybe 500 watt inverter in and maybe 2 golf cart batterys with a 80 watt panel. this way she can park her jeep in front of the playhouse and plug it in and also have lights to plus we can use it for pumping our rain water? what does everyone think to far out for the girls?

[juiced]

.. build a two-panel "roof" that she can take on and off. one panel vertical, one horizontal. maybe leave a "window" in the vert one?

[Ungrounded Lightning Rod]

Ok upon further diiging looks like the pv panel would be a little large for the hood of the jeep.

This is entirely reasonable.

The power required by an automotive application dwarfs the power consumed by a home - even an ordinary one, let alone an energy-efficient home trying to get along off-grid.

A horsepower is about 3/4 KW.  A car cruising on a level freeway at speed is using maybe 18-20 HP, and an off-road vehicle in less paved and/or more rugged terrain or a car on a shopping trip doing stop-and-go will be using significantly more.

So assuming three hours of use per day you need at least 100 HP HR, for the car, or 75 KW HR OUT of the car's batteries per day.  Assuming 5 solar hours for the insolation and a desert location with no cloud cover (where an ordiary house's needs would be covered by 5 KW of panels and an eco-freak's efficient house could run on a lot less), the car needs an additional 25 KW of panels times a storage inefficiency multiplier for TWO trips to storage:  The car will probably be in use during the day so you first have to store the power in the house batteries, then charge the car while the sun is mostly gone.  That's JUST for the car and nominal use, like commute or shopping in a nearby town.  If Barbie is doing a lot of cruising with her friends she'll need a bunch more, or she'll be prone to running out of juice while out on the town in the evening.  And for a rural setting - likely if you're doing a home-power system and a jeep - the local town is a long way away and probably over some serious hills.  (Hills are BAD - now you need over a hundred horse for long periods as you climb them rather than the 20ish for level cruising.  What would run you for an hour on the level is gone in 10 minutes of hill-climbing.  City  or rush-hour commute stop-and-go traffic is similar.)

So having an ENORMOUS solar instalation at the playhouse to power the car, because the car needs a LOT more than the house (like a factor of between 6 {mundane house, tiny car usage} and 60 {eco-house, moderate car usage}), is the right lesson to be teaching.

[Ungrounded Lightning Rod]

... 75 KW HR OUT of the car's batteries per day.  Assuming 5 solar hours for the insolation and a desert location with no cloud cover (where an ordiary house's needs would be covered by 5 KW of panels and an eco-freak's efficient house the car needs an additional 25 KW of panels times a storage inefficiency multiplier for TWO trips to storage:

Oops.  The 25 KW of panels would give you your 75 KW HR on three solar hours.  So some of your inefficiencies (or a little cloud cover, or a bit of stop-and-go in the vehicle use cycle) are already cranked in.

But you get the idea.  Cars need a LOT more solar panels than houses.  That's why electric cars don't just have panels on the car and be done with it - there just isn't enough sun hitting the car, even if the panels were perfectly efficient rather than 18% or so.  (The solar-powered vehicle contests involve ultralight, ultrastreamlined bicycle-like construction runing on nearly level deserts.  Not a good model for a car full of kids, groceries, and sports gear tooling up a wooded mountain or stop-and-going between the buildings of a city in a high-latitude cloudy climate on a rainy fall or snowy winter day.)

It's also why electric cars aren't a big hit.  Even with much improved efficiency and costs, better driving habits, (and cranking in the fact that cars would mostly be chargee at night when the other loads are minimum), you'd have to multiply the size of the power grid by a factor of 10 or more to switch the country over to electric cars.

[halfcrazy]

Ok another idea a friend gave me a 5 watt panel and a morningstar charge controller we are going to mount on the jeep this should supply like 45 minutes of riding on a full days sun i think. she goes 2-3 hours now on 9 amps so we will see. as soon as i get it done i will post pics for everyone