[puddleglum]

Originally Posted by Stubby79

You can get buck converters from ebay for cheap... for example,
https://www.ebay.ca/itm/200W-15A-DC-...0AAOSwr~lYrBBB for $10. There are plenty to choose from, and these ones can adjust the output voltage. You just need to wait for it to arrive from wherever it's coming from. Might be similar to your 24v one.

I doubt you need a diode, but it wont hurt to put one in. It will drop your output voltage a bit, and you may need to compensate.

Oh, and if all you are doing is EOC...unless you're coasting for 15 minutes at a time, I wouldn't worry about your existing starting battery to be able to keep up...unless you've gone and put a tiny lithium pack in or something. You should have plenty of reserve time in it to coast for a minute or two without a bother.

Yes my small converter is similar to that one, but a little different. I might pick one of those up though. Looks interesting and has a wider voltage range than mine.
I was concerned the reverse power output from the Alt. might damage the converter without a diode. You don't think it would?
I've never had problems yet with the battery only, but I have really short trips, mostly in the dark now with lights and it's pretty cold here. All that together is really hard on the battery and it never runs long enough to get fully charged by the alt.. That's why I think It needs some help. I've been charging at night but I'd like to ease the load on it.