The Meanwell supplies are output voltage regulated over a 90-250VAC input range, so the variac will not work, but Jims other technique was what Peter did on his first grid charger. The resistor will need to have some power dissipation 10-25W, and that will all be lost as heat, so the charge efficiency will be poor.
The advantage of the LPC-20-350 is that it is efficient, and does not need adjustments after the initial setup.
My battery testing is showing me that in an unbalanced subpack, the best cell may reach the delta V full charged point several AH before the weakest cell will get there, so having the charge rate decrease as the fully charged point approaches could really stretch out that balancing time, thus the 350MA CC.
I have had to put as much as 9AH into a subpack to get it charged fully for the first time. At 350ma, that could take several days.
My test are done with 4-6A charge rate, and I still see as much as 20 minutes for the last cell to reach delta V after the first has done so, and this is only 6 cells.
Running the battery fans during the topping stage is a good idea, as when all the cells are full, all of the input energy is going to heat.
I buy my power supplies from Powergate, and even if they have no stock, it usually only takes a week.
Last edited by Mike Dabrowski 2000; 03-16-2010 at 08:02 PM.
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