Need help setting up aux. lighting

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Expat E-biker
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Joined: 02/16/2009
Points: 10

I have a Chinese bike in China. The headlight is really crappy. I picked up a couple of driving lights in the US a few weeks ago and installed them. I couldn't find any way to tie into any 12V wiring coming out of the 48V to 12V converter. I found that when I tested one of the four batteries it was showing 12V even though it was still wired up to the other three. Testing the others showed 24V, 36V and 48V respectively. I wired up my lights to the first battery which showed 12V as a last resort. Is this ok? It seems to be fine, but will it hurt anything? I will only use it with the lights for about 7 minutes/day maybe 5 days/week. I usually ride only a few miles/day and charge it each night. I never do long rides at night. The existing controller is only about a 15A or so so I don't think adding the new lights to it (which work quite well) would be a good idea. What would you all suggest? Thanks!

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Formerly the proud owner of a Wanbaoulu (Marlboro) "Exquisite Article" model 500W scooter, currently the owner of a Lima 1200W 48V scooter

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marylandbob
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Joined: 06/22/2009
Points: 520
Re: Need help setting up aux. lighting

Doing as you are, you will unbalance your battery string! By using the first battery to both power the vehicle, AND your extra 12 volt load, you will discharge lt more than the others, causing it to improperly react during charging, and possibly become reverse charged if discharge were to be taken too far. Get a good D.C. to D.C. converter, having an input in the 36 to 72 volt range, with 13.8 volts D.C. output for your lights and accessories. (The so-called "12 volt" automotive lights, radios, etc are designed to operate best around 13.8 volts D.C.) there are some 36 to 72 volt input, 15.0 volt output units available, and the good ones have an internal "Trimming Adjustment" that allows you to set them to 13.8 volts D.C. output. If space permits, you could actually install another battery, such as a "Thunder Sky" 20 or 40 AH Lithium Iron Phosphate 4 cell unit, as your accessory and ligting battery, and remove this load from your motor battery completely!(You would have to charge the accessory battery by alternate means)--I use an auxillary 20 AH LiFePo4 battery to power accessories (Radio, extra lights, heated gloves) on my VX-1 Vectrix, and am happy with it, as it provides higher service voltage than a similar Lead-Acid battery would. I charge it up to 14.5 volts, and it operates at above 12.8 volts for a large portion of its discharge.-Newark Electronics and Digi-Key have D.C.-D.C. converters in their catalogs-pick one that has a current rating about 30% or better higher than your estimated load, in a suitable package for where you will install it. (Use proper circuit protection devices and wiring technique when installing) Bob Curry

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Robert M. Curry

Expat E-biker
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Joined: 02/16/2009
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Re: Need help setting up aux. lighting

Thanks for the info! I thought there would likely be some sort of issue so I have used the light very little. I tried the websites you mentioned. All I found was stuff that is not very "plug and play" as in the link below. Do you know of a good online source of scooter converters? I can probably get one here too, and probably cheaper, but they are probably not rated for many amps since they all have crappy lights. I thought ones for the US market might be rated for more amps. I have seen guys riding through the E-bike market in town with car stereos blasting on an E-bike. Maybe I can find out how they do it and do the same with my lights.

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=454-1123-ND

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Formerly the proud owner of a Wanbaoulu (Marlboro) "Exquisite Article" model 500W scooter, currently the owner of a Lima 1200W 48V scooter

marylandbob
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Joined: 06/22/2009
Points: 520
Re: Need help setting up aux. lighting

Try this battery and charger, (Listed below) from "Batteryspace.com" use it as an independent power source for your stereo and lighting. This battery will give the current (Up to 40 Amperes) and voltage needed for good lights and a stereo. Best to keep stereo to 200 watts or less, or battery will not last long, before recharge is needed! This battery includes the equalizing circuit. you could add a relay, to make it turn on when you turn the bike on.--Bob Curry

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Custom LiFePO4 26650 Battery: 12.8V 20.4 Ah (261Wh 40A Rate) in Aluminum-Box w/ PCB (CU-MM129 PID# 5189) CU-MM129
LiFePO4 26650 Battery: 12.8V 20.4 Ah (261.12 Wh 40A Rate) in Aluminum-Box w/ PCB

In Stock Sale Price Qty
N $299.95

Personalization
For safety consideration, please allow 1-2 weeks to build and fully test this battery pack before ship out.

Detailed Description
Custom LFP 12.8v 20.4Ah Battery w/ PCB in Aluminum Case

LFP 26650 3400mAh Cylindrical Cells (4S6P)
3 PCB PCB-LFP12.8V20A
6" 12Awg Charge Open Wires
6" 12Awg Discharge Open Wires

Size: ???

Weight: ???

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Smart Charger (3.0 A) for 12.8V (4 cells) LiFePO4 Battery Pack, 110-240VAC

Sale Price $21.95

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Robert M. Curry

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