Alternate power source question

[BlackwaterPark]

Is it possible to limit the charge rate to a maximum charge rate of10 amps and enable or disable this value through the aux inputs?

Wondering how viable this alternate charging set up is: rectifying the 120 vac from generator, filtered with a big capacitor, and then limit the charge to 10 amps so as to not overload a Yamaha 2000w inverter generator. Can this happen on the classic 150?

[Vic]

Hi BP,

In general,  using any external power supply into most MPPT CCs,  like the Classic is said to be a poor idea.   This  could damage the Classic,  under certain conditions.

Furthermore,  at 120 VAC RMS into the rectifier/capacitor will normally yield about 163 VDC peak output.   At the very least,  the Classic would probably not ever begin operation,  as this is in Hyper Voc range of a Classic 150.

It is possible to limit the Output current of the Classic to,  say,  10 Amps.  And this could accomplish the genset load-limiting,  but,  your source of charge power seems to be a bad idea for several reasons,  IMO.

Vic

[wk057]

I actually had a similar question.

I'm looking for a way to move power from one battery bank to another.  The first is my primary battery bank, 48V.  The other is a higher voltage battery bank at ~150V nominal.

Could I put the 150V battery bank on the input side of a Classic 200 and set the input current limit to something sane and presto?  Or no...

[zoneblue]

People keep asking this, and bob keeps patiently explaining that, (paraphrasing) IF you must do this, you need to make the IV curve more closely reseemble PV. The easiest way to do that is to add a suitable power resister in series with the input. That way the input source will then have, and the classic will be able to locate, a MPP.

[ebenbayer]

I have been using a 150 to do this between a 48 v and my old 12 v bank for about a year now (had an extra classic around so decided to try... the 12 V bank basically just runs a bunch of car amps for out door speakers). I did not add a power resister; I also tried the rectifier to genset thing before I got a proper inverter/charger set up. It worked... for a while... bad things happened to the cheapo generator before the classic! ( I manually chose the MPPT point).

Your mileage may vary.

E

[Vic]

The external Power Supply power source for any MPPT CC is risky.

In addition to the resistor often needing to be added,  it has been noted by MN Engineering,  that the closer the PS voltage into the Classis,  the better.

It appears that the Classic can protect itself from excessive output current by moving the MPPT operating point to limit current.  This may also be a way that the Classic may try to protect itself from heavy thermal loads  --  by moving the PV input voltage away from the Max Power Point,  thus reducing the output current and limiting the heating in the Classic.   With a stiff supply,  this strategy does not work well.

It as also been mentioned that if one simply must use an external PS as an input to the Classic (or KID),  that Legacy P & O should be used on the Classic,  and  (Legacy?) O & P on the KID.

Used to use an external Transformer/Rectifier/Capacitor Bank as an input to the venerable OB MX-60,  but this PS had a loaded output  voltage,  only a few volts above the battery V,  so it was more difficult for the MX to experience a large current overload.

Proceed very cautiously,  to protect your MPPT CCs,  including Classics.
Good Luck,  Vic