what amp hour size battery for dynamo

Hi George

What are you using for a voltage regulator? The battery should be protected by one and a sealed battery should be OK. I use a gell battery on my bikes, I'll dig the details out later and let you know what they actually are.

Andy

I have used a similar Yuasa battery with success, hidden inside a hollowed-out Lucas rubber battery case. I don't remember the actual model, but it was for a moped. That was with a standard Lucas voltage control, E3L and old-style light bulbs.

All being well, I will soon have the bike reassembled after a long hibernation, so I will have to decide whether to remain standard, or fit something more modern.

Paul

Previously George Phillips wrote:

Hi Skip - I've fitted a Yuasa 6N6-1B (6v) to my ES2 which is 6Ah. Mind you, it is a lead/acid unit that fits inside the old Lucas box. I also changed the bulbs to LED. So far no probs. The dynamo is a Lucas E3LM. When I tried a sealed battery I cooked it! Hope this helps. G

I am using a 6v x 4amp AGM battery (which are fully sealed) coupled to a DVR2 electronic voltage regulator (UK made). I find that the amp meter only shows a charge when the battery is not fully charged, and once fully charged the meter needle is central, indicating the charging system has apparentlyturned itself off,unlike the original Lucas mechanical regulators which seem to keep pumping the power in, even ever so slightly. Also, the AGM battery sits inside a soft foam pouch inside the original gutted outlead/acid battery box,to avoid vibration damage.

Paul

If your dynamo is properly regulated, it really shouldn't matter what amp hours your battery is. That said, I would go for the biggest that will fit comfortably on thebike, purely as a backup in casethe charging fails and I'm out after dark.

I have been running my Velo on the poxy little sealed battery it was fitted with (1 amp hr?) when I bought it 3 years ago without any problems. I will replace it with a 6 amp hr one soon...

The cheap Yuasa batteries have served me well and seem to cope with charge systems that are not well controlled,as long as not overfilled and fitted with a breather pipe. Some modern constructions need dedicated charge controll systems .

Some facts-ALL Classic British motorcycles dynamos and alternators and earlier have VOLTAGE regulators that only control the Maximum voltage at the battery. None of them concern themselves with the charge rate. The latter is a function of the state of charge of the battery and the load on the system. If you have your lights on all the time then the battery will survive as it will not be overcharged. But if you can manage long distance with your lights off then a small battery will get overcharged. But of course if you only nip down to the club and then come back with your lights on you will be ok.

To keep safe I have always suggested a 5 AHR as a minimum.

Sealed batteries-Another area of potential problem. A lot of sealed, 'square' batteries with Lucar terminals are intended for the alarm world. If you search out the specification of said battery (quite easy with the internet) you will often find the charge rate is a lot less than what you are giving it-it will fail. Don't assume or buy from the auto-jumble unless you can get the full spec. of the battery or get a receipt marked-'for automotive use'. You have been warned.

AL OZ

A Cyclon 5AH battery (Also available as a "Burlen" battery but you pay more!)

Very low self discharge, sealed and robust....prefer to use them with the Electronic DVR2 charge control unit

Les