David Roden wrote:
On 2 Jul 2008 at 17:25, Darryl McMahon wrote:In a ferro-resonant charger it matters. If you get a 115-volt unit and your input voltage is 120 or higher, the Lester will overchargebatteries.Odd that you would observe that behaviour. It's >not< characteristic of ferro chargers at all. Perhaps the one you used was broken.
Always possible I suppose. In my case, it was a 48-volt Lester that had a faceplate rating of 115 volts AC, and my garage outlet happily delivers 120-122 volts AC at night. This charger routinely gassed the batteries to the unpleasant rotten eggs smell point (8 golf-cart batteries). IIRC, the end voltage was slightly above 2.5 volts per cell, and the finishing current was 4 amps or higher. It was a long time ago, and I have stopped using it. IMO, the Lesters I used were generally aggressive on the finishing charge and relied completely on the timer to prevent excessive damage.
The output voltage of a ferroresonant transformer remains stable over a very wide range of input voltages. That's the whole point of the ferroresonant design. (The GE charger is a ferro design, btw.)
Never managed to get above 2.4 volts per cell or produce unpleasant smells with the GE charger in my ET.
Furthermore, with all due respect -- even without the stabilizing effect of the ferro design (that is, with a simple transformer charger), in a 36v charger, a 5-volt difference at 120 volts is the difference between 2.4vpc and 2.5vpc. For a flooded battery, that's not especially critical unless you're close to overcharge in the first place. And, as I say, the ferro design makes this a moot point. Or should, if it's working properly.The primary protection on the Lester is the mechanical timer.I wouldn't recommend any charger with a mechanical timer. I'm recommending only the Lestronic and Lestronic II range of chargers. They don't have mechanical timers, unless some user has added one.
Mostly, for 36 or 48 volt systems I have seen pretty basic chargers, Lester, Exide or whatever. Never a used Lestronic. The one Lestronic I have used was a 96 volt output with a 12 volt second output. It was specifically for EV charging, traction pack and accessory battery. The one I had did not have a manual timer, but IIRC, it was an option when ordering.
The tractor was stored at my cottage, and in that application I could not wait for the tractor to charge when I arrived. It needed to be ready to go when I arrived.I'd be hesitant to leave any battery on any charger unattended, when I couldn't check it at least a couple times per week.
Under better conditions, I agree. I did try out the Soneil originally with close observation for a full day, then daily for a couple of weeks, before committing to it in an unattended mode. It behaved precisely as expected and I have used it unattended for several summers now without incident.
I have not seen any Lester chargers for 36-volt output that will take a 230-240 volt, 60 Hz input.I don't know what they sell now, but I'm fairly sure I've seen older ones that did. I'll admit the possibility that I'm remembering them wrong, though.David Roden - Akron, Ohio, USA
-- Darryl McMahon Save water and your money. The Water Saver toilet fill diverter. http://www.econogics.com/WaterSaver/