FarHorizon

Against my better judgment, I bought one of these:

Robot Check

The thing came with no documentation at all.

They don't give the suggested voltage (I'm assuming 12v DC?)
They didn't give the plug polarity (I'm assuming tip hot?)
They don't say where to find a battery

So I'm sure that some of you have experience with these - Any help available with the previous issues would be greatly appreciated.

Thanks - FH

10 Wheels

https://www.fasttech.com/products/0/...0-battery-pack

prathmann

The spec. for the light indicates that the battery pack is a 6x18650, and these are normally arranged as three sets in parallel of pairs of serial 18650 lithium ion cells. Each cell is nominally a bit over 4V, so the voltage of the pack is 8.4V and with three times the Amp-hr rating of an individual cell. The battery pack listed above, with 8 cells, will also work fine and gives a higher Amp-hr rating for a longer tun time.

18650 cells are very common (the number indicates a diameter of 18mm and length of 65mm) and can either be bought individually or in a variety of bundled battery packs.

FarHorizon

Which is the best of the higher amp models?

10 Wheels

The 8 Cell will give you a Longer run time...I have one.

davidad

You will need a charger.
You could get this and use high quality batteries. PANNOVO B-C04 Water Resistant 4 x 18650 Battery Pack Case for Bike Lamp - Black - Free Shipping - DealExtreme
Four of these. PRE-ORDER Panasonic NCR18650B Protected 3400mAh

FarHorizon

Most 8-cell models are beyond my price range, but the FastTech one recommended by @10 Wheels looks good. What charger would it need?

And nobody's addressed the polarity question yet - the tip IS hot (positive), yes?

FarHorizon

I've ordered the 8.4V 8000mAh Rechargeable 8*18650 battery pack recommended by @10 Wheels. I've also ordered a TangsFire® High Capacity 8 x 18650 8.4V 8800mAh as a spare. To recharge, I've ordered a 8.4V Charger For Cree XML T6 18650, which looks like (?) it will work with both packs.

Is there anything else i'll need?

noglider 

It's a lot of work and expense to get these things going, isn't it? I tried. I'm happy now that I have lights specifically made for bikes. It removes a lot of work from the process. My advice is to cut your losses and don't invest any further.

10 Wheels

You did good...Now for warm weather.

FarHorizon

Warm weather? 68 here today (with 100% humidity) and I spent the day sweating...

noglider 

I guess I should move over so I, too, can be directly over the center of the earth.

FarHorizon

I use it to infuriate children on drives ("Where are we now?").

mrbubbles

Very bad advice due to your personal prejudice. Battery lights work fine for A LOT OF PEOPLE.

noglider 

Bad is in the eye of the beholder, and consider the price Farhorizon paid for my advice. For that matter, it's worth twice what he paid for it.

I've used battery powered bike lights. Lots of them are very good. This generic one from amazon is not what I consider a bike light, with its power cord and flimsy mount. I've tried high power flashlights. I came back to bike lights, because they're built for the purpose.

mrbubbles

He/she didn't pay anything for your advice and for the price he/she paid for the light (and the battery), he/she's got a very bright light (bike light or not). All that was missing was instructions.

If he/she were to start over again, I recommend this:

Yinding 900LM CREE XM L2 2 LEDs 4 Modes Cool White Headlight Lamp Set ( 4 x 18650 Battery US Plug )-46.05 and Free Shipping| GearBest.com

noglider 

Good powers of observation there! Usually, I'm the one who can't detect when people are joking.

KraneXL

Not very bad advice at all. In fact, OP gave 4 reasons just to his point. One also has to be suspicious when the price drops dramatically. In any event, advice is just that. He can take it or leave it.

CliffordK

I've got a little different style of Chinese CREE light which I like a lot.
It does chew up batteries though.

I have bought some 6000mah 18650 Lithium batteries on E-Bay that I just need to wire up, and hopefully get a little longer lasting battery pack.

One of the problems is that they go quickly from 100% to 0%. Mine has a red LED to indicate low battery, but I rarely see it before it blinks out. So, it always is good to carry one or two spare battery packs.

Also, DO NOT GET THE BATTERY PACKS WET. I have mine wrapped in plastic bags. The velcro on the cases could be better. Too long and narrow of a strap. Time to rebuild mine.

andychrist

Yes, a fire extinguisher.

Not trying to be snarky but really, stay away from cheapo battery packs and chargers. For one thing, the capacity of those packs will be a fraction of what's advertised, and often assembled using recycled cells or even slugs. Chargers might sometimes apparently work but won't have the best safeguards. Anyway if you must go budget at least buy a cell pack that comes in a waterproof boot rather than just shrink wrapped. The TrustFire I bought on Amazon was surprisingly well constructed, doubt though that it is really 6600mAh, probably 4400 at best. Fortunately the cable is relatively thick and sturdy, uses exact same connectors as MagicShine, the industry standard. Still, better to buy either MagicShine battery and charger or assemble your own pack and get a loose cell charger. Up front expense will be greater but performance and longevity will be many times better.

Sorry if this advice comes a bit late, just think everyone should be informed.

FarHorizon

Hi @andychrist -

Yes, there ARE better units available. If quality was my prime concern, I'd buy a Lupine system and be done with it. But for my use, I needed a combo of low price and occasional use. This rig won't be used in the rain, so I'm less worried about shorting. I knew from the start that the light wouldn't meet its spec, so somewhat less light is OK. The battery packs should be adequate for occasional use.

That said, I'm hoping that your fire extinguisher comment was hyperbole?

andychrist

Well there is risk while charging any battery; low grade or mismatched cells without proper protection are of course more potentially dangerous in this regard than trusted brands with built-in overcharge/discharge circuitry, especially if the charger is not particularly up to snuff either. Think TrustFire was once a well respected original brand, but because it caught on so well others copied it with names like SingFire, LingsFire, LusteFire, TangsFire, FandyFire,WindFire, BurstintoFire, etc. From what I've read there are even fake TrustFires on the market now (impossible to verify.) Big part of the problem is that at present there is no commercially viable way to recycle lithium batteries, so the tons and tons of those headed to landfill are scooped up by the desperate and repackaged by the unscrupulous. Thus 50% or more of what seems a working battery pack might be dead weight, and the rest barely functional. Doesn't mean that every pack you buy for cheap will be complete garbage, just that there is little consistancy and what you get is pretty much the luck of the draw. Fairly decent cells are oft discarded alongside the duds, and manufacturers are still producing new cheap cells. Just have to be aware that the plant assembling your bicycle lamp generally has no relationship at all with that churning out the batteries, they are entirely different fields of endeavor. As mentioned TrustFire was at one time more reliable and perhaps they do actually produce both their own (mediocre) Li-ion cells as well as all those (fairly top-notch) LED lamps, they're a big company. But because of all the copycats, only sure way to guarantee you're getting genuine quality cells is to buy name brands from reputable vendors. Even the cheaper Chinese companies like MagicShine and I think also maybe NiteFighter and O-light include top of the line battery packs and fairly decent chargers along with their lamps. Yes you have to pay considerably more for them than for a Fire!Fire! but they're still a fraction of the price of a Lupine, and for those who intend to use their bicycle lights for any amount of time the cost is easily justifiable. OTOH if you're only going out on short jaunts and your lighting isn't all that critical, than sure, FlamingFire brand cells might be fine for your needs and you'll save like $40 to $60, nothing wrong with that. As long as you you've got good insurance on your house.

Hope I haven't scared you too much or discouraged you from enjoying your new light. Because even the lowest end LED/Li-ion setup nowadays will knock your socks off.

Enjoy the ride!

noglider 

Funny stuff, @andychrist! But fair warnings, too.

As a very alternative approach, it is also possible to build a cheap dynamo system. I've bought a few old sidewall dynamos off ebay, and they work fine. There are some inexpensive headlights that are built to run on dynamo power. I bought a B&M old model whose main emitter is halogen, and it has a standlight LED. The light is not amazing, but it was cheap, and it's more than adequate for occasional use. The light bolts onto the bike, of course, and so does the dynamo.

This is far from perfect, but if cheap is what you need, it works, and it is immensely reliable. Obviously, one downside is that when you engage the dynamo, there are noticeable drag and noise.