alternator charding Odyssey TPPL batteries

[ArgleBargle]

Hi

Anyone think the standard 60 A alternator on a yanmar 3YM will burn out charging two Odyssey PC2150ST-M TPPL batteries in parallel (ca. 200 Ah total @ 12V) given their apparent high rate of charge acceptance or otherwise have any experience with these?

cheers & thanks

[sailingdog]

A lot will depend on how far you draw down the batteries. The lower the batteries are, the greater the acceptance current rate will generally be, and this is generally far more drastic for AGM batteries than wet cells, which are generally limited to about 25% of the amp-hour capacity for their maximum acceptance rate.

[hellosailor]

Standard alternators aren't supposed to burn out, they are supposed to be set up with the ability to "throttle back" and lower their output as they heat up. If it has an internal automobile-type regulator, thermal regulation should be a part of it. With an external regulator, you might have a problem from not having that protection.

Wet lead cells are generally considered to take a charge at 20% of their rated capacity (i.e. 20% of their amp-hour rating) while AGMs are generally considered to accept at 25%, so it is not a great difference between the two.

Heat damaging an alternator is pretty easy though, even an extra coat of paint that gets onto the heat sink or diode frame can kill it. Adequate airflow can also be problematic in an engine compartment, so there's more to consider than just AGMs.