The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: BooG on July 15, 2014, 02:25:22 PM

Title: Battery thing
Post by: BooG on July 15, 2014, 02:25:22 PM
Hi all!
Can I stick a 22ah mobility scooter battery on my R65?
It only costs £39.99p, and seems to be of smaller dimensions than the Odessey PC680.
Cheers!
Title: Re: Battery thing
Post by: Bob_Roller on July 15, 2014, 02:30:53 PM
Yes, you can do it .

You can place foam, or other material in the space between the battery and box, so the battery doesn't move around .

I've been using generic AGM batteries, that were meant for computer back-up power sources .

But they are the same size as the battery that goes into the R65 .

Less costly than ' motorcycle ' batteries .
Title: Re: Battery thing
Post by: BooG on July 15, 2014, 02:33:12 PM
Cheers Rob!
That means I am a very happy bunny!!!
Top call!
Title: Re: Battery thing
Post by: nhmaf on July 15, 2014, 04:18:49 PM
You certainly can do so, but, in *theory* anyway, the better motorcycle batteries are designed internally to better cope with the vibration and shock of road usage that some of the electric wheelchair/scooter batteries do not experience.   So, you might find that you see shorter service life with those batteries -- or you might not!
Title: Re: Battery thing
Post by: Barry on July 16, 2014, 02:16:35 AM
There are many here using non motorcycle specific batteries including me now for the first time. The lower cost is certainly attractive and in the UK I could almost buy  3 low cost batteries for the price of a PC680. Vibration I would think is more of a problem with wet cell batteries than with an AGM or Gel which are inherently less susceptible.

This is the one I'm using which is being marketed as an automotive battery by the retailer although not by the manufacturer. There is also an AGM version at the same price and very detailed data sheets for both are available from the manufacturers web site. I really liked the vertical screw terminations which are much easier to access although they could ideally do with some covers for short circuit protection.

http://www.ebay.co.uk/itm/12V-20AH-MOTORSPORT-LIGHTWEIGHT-6KG-RALLY-COMPETITION-RACING-CAR-GEL-BATTERY-/121273253589?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item1c3c72fed5
Title: Re: Battery thing
Post by: wilcom on July 16, 2014, 09:09:44 AM
Quote
It only costs £39.99p,

The batteries at Gruber are of similar cost and are suggested for motorcycle use in the fine print
Title: Re: Battery thing
Post by: Lucky_Lou on July 16, 2014, 11:38:07 AM
Quote
You certainly can do so, but, in *theory* anyway, the better motorcycle batteries are designed internally to better cope with the vibration and shock of road usage that some of the electric wheelchair/scooter batteries do not experience.   So, you might find that you see shorter service life with those batteries -- or you might not!
Have you seen the speed some of the Muppets ride on these "mobility Scooters" I put a Gel battery on mine without any issues and its been on for years.
Lou
Title: Re: Battery thing
Post by: clonmore1 on July 16, 2014, 01:03:39 PM
And they are speed limited!

I think they can go at least twice as fast as they are allowed.
Title: Re: Battery thing
Post by: marcmax on July 16, 2014, 02:19:16 PM
We have a city near where I live in Florida that is all retirees. They actually have an age restriction in their zoning to keep anyone younger than 55 from living there. If you are going to visit a parent, they have to register you and you can only stay a few days.

They all drive around in golf carts, on the paths, on the roads, everywhere. Some of these "retirees" were engineers and they have modified their electric golf carts with bigger batteries, bigger motors and modified motor controllers. The local police have stopped these guys in excess of 60mph in an electric golf cart.

Maybe their mobility scooters are next!
Title: Re: Battery thing
Post by: Bob_Roller on July 16, 2014, 02:21:49 PM
I've wondered how long the generic AGM batteries that I have would last in a motorcycle application .

With the heat here in the low desert, very few batteries for motorcycles last beyond the 2-3 year range .

My first Odyssey PC680 lasted a little over 5 years, I got it in 1999.

My second one, only 28 months, got it in 2004 .

Since 2007, I've been using the generic batteries .

I'd like to know what service life this battery would have in a cooler climate .

http://www.gruberpower.com/12-volt-18-amp-hour-ah-battery

If you scroll down to the bottom of the page, it shows applications, from computer back up power, to motorsport applications .

Title: Re: Battery thing
Post by: Barry on July 16, 2014, 02:53:55 PM
Bob,

I'd bet in a more moderate climate those batteries could easily last twice as long.

Your experience of the PC680 confirms my reason for never buying one. It's too much of a lottery. At $32 for a generic AGM you really can't go wrong by comparison. If you are going to pay an outrageous price for a battery you have the right to expect guaranteed long life. An automotive battery of that quality should come with a minimum 5 year guarantee and even then it's too expensive. There's nothing magic about Odyssey batteries they are just very high quality AGM's.

As for the $32 generic AGM being suitable for automotive use the internal resistance of 10 milli ohms and the ability to deliver hundreds of amps suggest they should do the job just fine. The specs for my £33.99 battery are very similar. Before choosing a generic battery I did a bit of research on what current the starter draws. Our Bosch starters are rated at 320 A but I don't believe for one minute that they draw any where near that level of current in normal use. 320 A will be the maximum stall current and I suspect that would be at 12 Volts. I concluded that a starter typically draws 120 amps or less. It's not a simple linear thing though. If you were to plot the current draw there would be a high initial current which drops rapidly within a tenth of a second once the motor is spinning but even the initial current is well within the capability of these generic batteries.
Title: Re: Battery thing
Post by: steve hawkins on July 17, 2014, 02:06:17 AM
Can these AGM batteries be mounted in any orientation?  Or are they still 'wet'?

Cheers

Rev. Light
Title: Re: Battery thing
Post by: Barry on July 17, 2014, 02:13:59 AM
Every one I've seen says any position except upside down. Both AGM and Gel by definition have the electrolyte immobilized and they will not leak but they are all valve regulated Lead Acid (VRLA) so presumably upside down would compromise the safety pressure relief vent.

Venting is one of the things that will kill these batteries off early. The relief valve is set to a couple of PSI so that any gases recombine into the electrolyte. If the battery is overcharged and the safety vent does gas off that represents a loss of electrolyte that can't be replaced. To this extent they are more sensitive to overcharging than wet cells which can be topped up. In proper use though they should never vent.
Title: Re: Battery thing
Post by: Dizerens5 on July 17, 2014, 05:57:59 AM
Just a thought on batteries. Modern telescopes used by amateur astronomers are (of course!) all computerised now, with "go to" automatic search and motor driven movement. This demands a lot of electricity. I don't have any of this exotic equipment myself but I do know that quite impressive rechargeable batteries are available, they are lithium polymer type, vary from 8 to 22 Ah and look as though they might fit an R65 battery space. Expensive but probably robust as they are intended to be taken to remote dark-sky locations. But maybe the BMW's charge rate would be too high?
Title: Re: Battery thing
Post by: Barry on July 17, 2014, 06:25:54 AM
Is that where your handle "Constellation" comes from ?  I always assumed it was the Royal Enfield model.

I built a 6"reflector in my teens and used to do some photography at the focal plane.  Having seen how Hi tech and relatively cheap telescopes have become I've been tempted to get back into it or at least I would if I lived somewhere with darker skies.

From what I've seen one limitation on utilizing non automotive batteries is the type of terminals they have.  There are some batteries available that would crank an airhead if only they were fitted with something more substantial than spade terminals.
Title: Re: Battery thing
Post by: DerekM on July 17, 2014, 04:46:08 PM
http://youtu.be/i2D2fP6yBzU  :D