battery now only showing 11v, wont take a charge,
need to get a new one, any recommendations for the t160.
After my last original Lucas T160 battery finally expired in the mid-1980's, I used the same Varta batteries that Les Williams fitted in his Rita-ignited Legends (as you might know, anything mechanical/electrical Les changed on those bikes was for reliability); they were 11Ah (Amp-hours) and the last ccA (cold-cranking Amps, for electric-starting) I found on the Varta website was 90 ccA.
Closest modern 'maintenance-free' battery to the Varta in both Amp-hours and physical size is the Motobatt MB9U
; however, that produces up to 140 ccA. If you'd like even more ccA while still not filling the space allowed for the original Lucas battery, Motobatt MBTX12U
can produce up to 200 ccA.
Both of those will allow you to fit the battery with the +ve terminals closest to the sidepanel and drive-side frame seat tube while attaching the cables at either the front or the rear; attaching at the rear (ideally having a ~3" longer battery-negative-to-starter-solenoid cable) allows much easier refitting of the sidepanel.
If the Motobatt Vile Yellow colour offends, Yuasa YTX14-BS
is a similar physical size to the MBTX12U, if slightly lower Ah and ccA (though still higher than the aforementioned Varta). It only has two terminals and, if fitted with the +ve terminal beside the sidepanel and under the frame tube, the terminals will be towards the rear of the carrier.
I've never known any electrical unreliability with a MB9U until it gets very old (10+ years old); given the MBTX12U and the Yuasa produce more Ah and ccA, can't see why they'd be any less reliable. Given standard engine cc. and compression, never known any need for a battery a similar physical size to the original Lucas.