Heat generation from Victron DC to DC Charger

[dLj]

This confuses me. Your description is how all regulators work. They do so because the battery accepts less current as it becomes full, so all regulators automatically ramp down the output accordingly. For all external regulators, including the Balmar, once float is reached, the alternator output is effectively shut down (or operates at the set float voltage if one has programmed that to be higher).

You must be confused between lead acid, and lithium. Lithium takes as much power as you can throw at it until it's full and then it shuts down - like a door slamming shut - not at all good for alternators.

dj

 

[dLj]

The Wakespeed has the ability to adjust output based on RPM, as does the Zeus. The Zeus just has an easier interface (from the old Wakespeed anyway). The nice feature the Zeus has that WS doesn’t is ”Generator mode” that ignores any RPM pullback. This is useful when charging at anchor.

Good to know - thanks!

dj

 

[colemj]

You must be confused between lead acid, and lithium. Lithium takes as much power as you can throw at it until it's full and then it shuts down - like a door slamming shut - not at all good for alternators.

dj

No, this is not at all how lithium works.

There is no difference in this between lead and lithium, except that lithium gets to a higher state of charge before it starts limiting its current acceptance. On ours, this occurs at ~90% SOC, or when the cells reach ~3.4V or so. Above this point, the current ramps down gracefully to a few amps as the SOC approaches 100%.

A flooded battery might start doing this at 50-60% SOC, while an AGM might not start until 80% SOC.

All batteries, regardless of specific chemistry work this way. It is a fundamental aspect of general electrochemistry.

It does not take full charge until it is full, then slams shut. The slamming shut would be the BMS, not the battery charge acceptance. But even the BMS should not slam shut once the battery is full, and the charge rate should make no difference to this. If your batteries are behaving like this, then there is something wrong with them.

If you have made ad hoc adjustments to your alternator based on this misunderstanding, you are slowing down the time it takes to charge them for no reason. If these adjustments are somehow necessary to keep your batteries from slamming shut to a charge source, then there is something wrong with your batteries.

Mark

 

[dLj]

No, this is not at all how lithium works.

There is no difference in this between lead and lithium, except that lithium gets to a higher state of charge before it starts limiting its current acceptance. On ours, this occurs at ~90% SOC, or when the cells reach ~3.4V or so. Above this point, the current ramps down gracefully to a few amps as the SOC approaches 100%.

A flooded battery might start doing this at 50-60% SOC, while an AGM might not start until 80% SOC.

All batteries, regardless of specific chemistry work this way. It is a fundamental aspect of general electrochemistry.

It does not take full charge until it is full, then slams shut. The slamming shut would be the BMS, not the battery charge acceptance. But even the BMS should not slam shut once the battery is full, and the charge rate should make no difference to this. If your batteries are behaving like this, then there is something wrong with them.

If you have made ad hoc adjustments to your alternator based on this misunderstanding, you are slowing down the time it takes to charge them for no reason. If these adjustments are somehow necessary to keep your batteries from slamming shut to a charge source, then there is something wrong with your batteries.

Mark

I'll keep this in mind - my system works perfectly and has for years now.

dj