Light Aircraft Association

The project is whipping along now, and one problem I've got is replacing the old steaming lead acid 12volt 'car' type battery with a more effective and lighter version. As this is a restoration, the battery holder is being replaced anyway so no worries about exact dimensions. It has a fairly standard low power electric system - radio, transponder, elec T/S, GPS, fuel pump. The starter is a lightweight B&C: BC320-H; lightweight B&C 200G Alternator. The power unit - an 0200.

I am trying to keep the battery weight and size as sensible (small) as possible, but don't want to go over board with a 50 ah 12kgs version. What would be the 'correct' type of unit to crank this engine and keep it charged? a 12v 25ah perhaps? or less? A good supplier as well, wouldn't go amiss!

Thanks in advance.

Varley's "Red Top" batteries from Demon tweeks are very good. Google will point you to either Demon Tweeks or another supplier. They are light, powerful and sealed, which means they can even be mounted on their side if it suits.

Ivan
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glass bubblers

Have a look here: www.batterymasters.co.uk

I recently bought a 12V 30 Ah sealed battery from them. Service and price was good.

Most of the RVs are going for the Odyssey PC680 recommended by Vans.
About 7 kg, 17AH, rated at 500A for 20 seconds.
You should be able to source one in the UK for about £90.

YUASA do sealed 35 Ah units that are about £65 ish. I know because I was going to get a direct replacement for the one in my Pitts when I thought I was having battery problems. I ended up forking out for a concorde sealed unit from LAS for about £120 ish in the belief that it would be better. In practice theres not that much difference as I can tell; both were just about adequate to turn the engine over from cold. (My engine has a lot of compression).

Recently I had a complete starter failiure which I traced to a high resistance contact in the battery master solenoid, and now I've replaced it, both batteries turn the engine over well - now I have a spare!

Yuasa 17Ah sealed battery - about £35, fitted one to our Christen Eagle. Would give at least 5 start attempts on an IO-360

Nice, light, cheap.

Thanks for your help chaps, I've got myself an nice 12v 21ah battery with 250 amps crank. The next issue I now have is the wiring. Most of the the old loom is passed it's sell by date and not really usable. I'm at odds as to replace with silicon rubber covered cabling or go for Tefzel, the latter appears to be v. expensive indeed and harder to route, but silicon is allegedly prone to chaffing - yet cheaper and more flexible. Any experience with either would be appreciated as at this stage I can choose either solution.

Andrew

No worries gents, I discussed the wiring offline with a couple of avionics engineers and they put me on to a company in the U.S who are markedly cheaper for Tefzel than the UK even with duty & vat (if I'm unlucky to be charged!). So I've ordered a big batch for now. I did find that the only company that dealt with silicon wiring was RS and had to buy it on 100 metre reels but they didn't have all the heavy duty 8 awg +sizes.

A