Battery recomendation for Triumphs

MRB said:

I need a new battery for my 71 Triumph. The bike only runs a head and tail light.
I want to use a sealed maintenance free AGM unit but not sure what size. I found two that should work YTZ-7S and YTX7L-BS. Both will fit but are only 6 amps. Is that enough or too small, will the bike over charge them?
Thank
Mike

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Mike,

As long as they fit without shorting out the posts on the seat pan and they are 12V, they should work fine. The size of the battery and the amperage rating has nothing to do with your bike 'overcharging' it. You don't need much current from the battery on your bike if it only runs the ignition, headlight and tail light. If your charging system is in order, it should supply current to the battery as long as the voltage is under a given threshold. Once the batter reaches it's design voltage, the charging system should stop providing current to it. Your bike should have an Ammeter in the headlight shell. Upon startup it should show a positive rate of current then taper off after running for a few minutes. If it constantly charges, you either have something drawing too much power or your regulator is faulty. If you haven't changed out the stock regulator, the modern solid-state replacements are a very good improvement.

6 AH is just right. Having pretty good luck with those Scorpion batteries these days, check em out. batterystuff.com..........website seems to be hosed right at the moment.

I've used the YTX7L-BS on a couple person builds and all my recent buddies builds, some points ignition and some electronic. Couldn't be more happy with the results. Highly recommend the yuasa brand, spend the extra money. Crap batteries fry electric systems.

I've run the same YTZ-7S in my '68 Bonneville since 2008 I think. Given the non-stock mounting location it's seen way more than it's fair share of vibration, shock and grime. Some of the best money I ever spent.

Thanks all for the great information. Found a site that sells them for $45.00 a pop and free shipping. I'm stocking up.
MRB

Watch out for sites that list "Yuasa compatable" model numbers but that aren't actually Yuasas. The lowest price I've regularly seen for a YTZ-7S is about $100. $$$ but worth the money if it's a bike you ride a lot IMO.