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Thread ID: 82578 2007-09-01 05:03:00 Solar battery charging tedheath (537) PC World Chat
Post ID Timestamp Content User
586833 2007-09-01 05:03:00 Are there any experts out there in this field. I dont want any clowns guessing.
I am getting sick of jump starting truck when flattened by swager and saw during a big job. I have used a 230 vac to 12vdc small charger which gives 2 amps (on ampere meter) by plugging into customers power and its been sweet. But a lot of !@#$%^& around and some asian customers have whinged, and reckon I should deduct moulah from my invoice for their power!
I presume with ohms law a 25watt solar panel for 12vdc would do.
Would you really get 25 watts when its real sunny? how many watterunis would I get on a cloudy day?
Do you need to buy an extra charging regulator?
Will starting engine cause a back feed and smoke the panel?

thanks

tedheath
tedheath (537)
586834 2007-09-01 05:15:00 going by dicksmith prices about $300-400 for the panel and then a regulator. you need a regulator ($50-150) otherwise you will overcharge the battery. cool setup to have it built into the roof of the vechile ;)

don't forget you will need bigger panel than you think to allow for weather and the drop in power as the panel gets older. also may not be very good if you work till dark.

cheap way, carry one of those jump starting packs or use a cheap genny to run the gear off. most of the guys that use power tools out on sites just use cheap generators.
tweak'e (69)
586835 2007-09-01 05:23:00 We have a 125 watt panel which produces 8 to 10 amps tops ie middle of summer. Cloudy day mid winter 2 to 4 amps. A 25 watt panel would be insufficient OK good sunny days, next to useless otherwise.
Need separate deep cycle battery and solar panel to run tools leaving truck battery separate. Solar panel size depends on $$$$ :)

Contact AA Solar in Silverdale for all required info.

Dictated by DH while we are sitting in our MotorHome on 4.6 ltr truck with 2 x 125 Watt Solar panels plus Separate alternator for charging 6 x 6Volt Deep cycle batteries, approx 700 amp hours.

Also carry a Generator for watching TV in the winter :)
Sue (33)
586836 2007-09-01 10:45:00 I should deduct moulah from my invoice for their power!

Get yourself a 10 cent piece, cut it into quarters and offer one to the tight-ar*es !
decibel (11645)
586837 2007-09-01 11:03:00 LOL about cutting up coin I will try it,
Thanks for replies think I will go for 75 watt panel so should be ok when cloudy.

tedheath
tedheath (537)
586838 2007-09-01 11:11:00 There is a reason why I asked about starting the truck engine and smoking the regulator and panel. I have smoked two battery chargers when I have started engine with battery charger on.
Auto sparky said it is caused some sort of reverse polarity thingy.
More batteries out of question because of weight, I am right on GVM.


TEDHEATH
tedheath (537)
586839 2007-09-01 23:51:00 i don't know about the newer type of chargers but some of the old (cheap) ones don't like big current draw. ie starting a motor is like shorting the terminals. the transformer dosn't last long.
howeve the new ones are all current regulated etc so that shouldn't happen. its still best to take the bat charger off before starting.

i don't think you will have a problem with the solar regulator.

75w? not going to have much change out of $1k.

btw what vechile do you use ?
tweak'e (69)
586840 2007-09-02 03:21:00 The wattage rating on a solar module is a lie . :D

It is a wattage rating under "standard" illumination, but you can't actually get that amount when charging a battery . If you look at the specifications, that is the maximum power, given at about 17V (for a 36 cell panel) . Your lead acid battery won't get to that level (if it's in usable condition ;) ) .

You'll never get the standard illumination, either, because of clouds and pollution . You are unlikely to use a sun-tracker mount on a vehicle, so you lose input that way too .

In a "topping-up" application, 32 cell panels are better than 36 cell ones, because they are pretty well self regulating .

A regulator will have a reverse-blocking diode in it; standalone modules should have an isolating diode in the circuit .
Graham L (2)
586841 2007-09-02 03:24:00 i thought the regulators wher PWM ?? it wouldn't matter what voltage goes into them. tho i fully agree, manafactures specs always lie ;) tweak'e (69)
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