12v battery replacement (total loss ignition) AAs?

[Korea]

Hey all, been tooling around with the bucket and reckon there's weight savings to be had!

For example, the 12 volt, 7.2Ah, 2.5 KG battery that runs the total loss ignition on the RG/RX125...

The current battery (fully charged) is about good for a full days' riding. But I was thinking of running 8x1.5v AAs in serial (=12v).
Will this work?

Only problem I foresee is that at about 2200mAh, they'll probably last about 20 minutes on a charge...

So got thinking about the old Tamiya RC car battery packs and how we used to quick charge them off the car battery (15 minutes to full). If I used rechargeables, anything stopping me charging on the car battery between races?

Any reason this won't work, did I miss something? What do YOU think?
1. current battery
2. tamiya pack
3. Dick Smith battery holder

[quallman1234]

I know Glen Skachill's old RS125 runs a total loss, with a 3AH 12V battery. Seemed to last ages! When i rode it we never had a problem even when we forgot to recharge it one day.
You could use recharageable AA's.
Hook it up to a 15 minute quick charger between races and it should be sweet.
You can get 1200mah ones (each). (Only 1.2V one's tho!)
So a 4 pack should be alright i think?

Also watch out as alkaine batteries will fail due to vibration. So your need to use NiMh ones. (Learn't this by killing heaps in my helmet cam).

[johan]

http://shop.durbahn.de/shop/en/produ...ePower-Durbahn

Check out the LiFePower Pack 2.3 Ah

[Korea]

http://shop.durbahn.de/shop/en/produ...ePower-Durbahn

Check out the LiFePower Pack 2.3 Ah

Looks good, but at € 94.16 a bit pricey for buckets. Is the amount of current / drain through batteries going to be a limiting factor?

[saxet]

The life span of the battery is gonna depend on the load 7.2Ah means it'll supply 7.2A for an hour or 0.72A for 10 hours. I've seen people swappin batts between races but with rechargable batts in the AA styles I'd wanna be sure they're not gonna blow up if you do a fast charge off a car batt.

[speedpro]

Dave Diprose runs cordless drill batteries. quick change and fast charge. I'd go for 14.4V ones myself. Go and buy a drill, most come with 2 batteries then you only need the connector.

[SHELRACING]

Ask yourself what will you gain. you may drop 1.5kg and will get in return what ?

Your current battery is good for a days racing. Hassle free. leaving you to chat, fix other bikes, or whatever. or you have a system needing constant maintenance through the day.... What if you were to run the Taupo GP

If you want to drop weight, look at how much gas you're carrying in your tank. Diet you 3 days before a race meeting......

Hmmm... I'd stick with wot you've got

[Korea]

Ask yourself what will you gain. you may drop 1.5kg and will get in return what ?

Your current battery is good for a days racing. Hassle free. leaving you to chat, fix other bikes, or whatever. or you have a system needing constant maintenance through the day.... What if you were to run the Taupo GP

If you want to drop weight, look at how much gas you're carrying in your tank. Diet you 3 days before a race meeting......

Hmmm... I'd stick with wot you've got

Yes, yes ~ you're right (of course) just exploring options to make a nice bucket even nicer!

[k14]

The NiMH batteries are supposedly the best for total loss. You can't use a LIon as it doesn't like the big current spikes that occur on a bike. I am unsure about the new LiFe batteries. Their current density is unmatched and they may come in very handy in the future. Their price is a bit high at the moment but that will come down.

One thing you must be very careful with when charging the new type of battery is to get the proper charger for them. A lead acid can take a fast charge and have a reasonable long life. However with the LiFe and NiMH they are very succeptable to overcharging and this severly limits the life of them. Try www.all-battery.com for a very wide range. I've purchased a few times from them and their service has usually been very good.

[SHELRACING]

Yes, yes ~ you're right (of course) just exploring options to make a nice bucket even nicer!

Fair enough, and if you find a good soloution let me know............. Cos I'm building another

you could experiment a lot by removing the flywheel... I'd suggest you find another one (don't use your existing) . Remove the centre, throw away the heavy bit and refit the centre piece.

[Sideways Sam]

If you're looking to save weight the battery has to be the place to start.

I've got the same issue from another angle on the FXR, having run magneto only (no battery) that won't be sufficient for the EFI system which requires some voltage for a few seconds before starting and also need something to buffer the peaks and lows of the existing system.

Because of this I've been toying with the idea of doing exactly the same thing as you, a small rechargeable battery. It doesn't need to drive a starter motor just run the electronics but I'd still like to have it charge off the bike in real time for reliability. I've seen too many people not finish races because of total loss problems.

[b1kerb0b]

Also watch out as alkaine batteries will fail due to vibration. So your need to use NiMh ones. (Learn't this by killing heaps in my helmet cam).

Ahhhhhh, now i understand why they kept dying!

[SHELRACING]

If you're looking to save weight the battery has to be the place to start.

I've got the same issue from another angle on the FXR, having run magneto only (no battery) that won't be sufficient for the EFI system which requires some voltage for a few seconds before starting and also need something to buffer the peaks and lows of the existing system.

Because of this I've been toying with the idea of doing exactly the same thing as you, a small rechargeable battery. It doesn't need to drive a starter motor just run the electronics but I'd still like to have it charge off the bike in real time for reliability. I've seen too many people not finish races because of total loss problems.

Total loss systems have many advantages, failure in a lot of instances is lack of care and maintenance. If you dont charge your batteries and do it properly, and you don't have at least one spare battery.. then the inevitable will happen.

My latest project is running a so so simple points system, on total loss. It's reliable if maintained. Easy to diagnose, and I can ultimately ditch the magneto my crank works so hard to spin around at 10,000RPM.
Compare the weight of the magneto on the end of your crank to a battery.
I'll take the battery.