16 volt system with alternator.

[countrypuppy4865]

You shouldn’t have any issues mine charges at 18 with the powermaster adjustable alternators and really don’t need to charge it. I would suggest checking your alternator rpm you may want a larger pulley to prevent it from spinning too fast. Since it is adjustable if you would prefer to lower the setting to around 17.2-17.5. However, under a load it won’t be that high.