Using batteries for a dynamo light

[NEvans]

Looking at mounting a dynamo light, something like a Busch & Miller, but will then attach it to a battery set either standard or rechargables. The light has two power cables, is it 1. Ok to use batteries as the power supply and 2. Can someone suggest a good battery pack.

Thanks

[freeflow]

You might be most of the way there with something like

http://www.spacycles.co.uk/products.php ... b0s38p2946

I've just acquired one and gave it its first trial last night and found it quite impressive compared to my Exposure Light Enduro and cheapo Chinese '1000 Lumens' cree light. The power cable is of course not compatible with Magishine type battery packs but I think a trip to Maplins this afternoon should sort me something out.

[SA_SA_SA]

Perhaps you would be better with E-bike lamps (designed to run at full brightness from, eg, 6V up to double-figures Volts DC).

http://www.bumm.de/produkte/e-bike-beleuchtung.html
http://www.bumm.de/produkte/lumotec-iq-cyo.html

I am not sure that all dynamo lamps will work at full power from DC (and the battery voltage must be less than the overvoltage protection diodes: 7V5 for B&M I think). The Herrmans H S one doesn't even like DC at all it seems!

[stewartpratt]

FYI: http://mccraw.co.uk/battery-powered-dynamo-lighting/

[beardy]

B&M do make a battery version of those lights.

http://www.rosebikes.co.uk/article/b--m ... aid:703598

This is a little dimmer than the Cyo equivalent but that is because it is battery driven rather than dynamo driven. When connected to a dynamo the Ixon gets as bright as the Cyo, so I guess the Cyo will be the same as an Ixon when battery powered.

That only applies when you are going fast enough for the dynamo to produce its full output at other times the battery version can be the brighter one.

[NEvans]

B&M do make a battery version of those lights.

http://www.rosebikes.co.uk/article/b--m ... aid:703598

I am looking at options because I will be mounting it at the top of the forks (due to a bar bag on the handlebars), which is why I've considered using a B&M light, this would work as they do an adaptor for this style mount.

[beardy]

I think that you are talking about this adaptor

http://www.rosebikes.co.uk/article/b--m ... aid:409690

but I have linked it incase you were not which will allow you to mount the Ixon as you would a Cyo unless you have canti straddle wires in the way, in which case you may need to swap the stainless steel bracket for one of these.

http://www.rosebikes.co.uk/article/b--m ... /aid:50127

[freeflow]

For the Dosun 400 I cut the cable between the switch and connector and soldered in a 5x2.1 mm power connector (as used by Magishine et al). The light now works with either a Magishine type battery pack or the original battery pack.

[MikeF]

Looking at mounting a dynamo light, something like a Busch & Miller, but will then attach it to a battery set either standard or rechargables. The light has two power cables, is it 1. Ok to use batteries as the power supply and 2. Can someone suggest a good battery pack.

Thanks

What's the reason to use a dynamo light with batteries?

If you do connect the light to a battery it might specify which way the polarity should be, although I don't know the reason for this.

If you have a rim braked bike it's not that difficult to either build a hub into a new front wheel or into the existing one. Put the wheel into the front forks and you can true it up using that way. No more faffing with rechargeables and a light whenever you need it.