Kid Charge controller on AC input

Started by karlsolar, April 03, 2018, 08:53:53 AM

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karlsolar

Hi all,
So I just bought an electric boat.  it has a 48V elctric motor, and 4x12volt batteries.  I discovered quickly that the included charger is wonky and probably wasn't appropriate anyway.  Of course you can't have an electric boat without adding some PV to it, so I was going to add a couple 190 watt modules (or something, I'll see what's laying around the shop and what will fit well) using a KID CC to handle the batteries. 

most of the time I'll be happy to let the PV on the boat charge the batteries, as the boat will only get used every other weekend or so.   but there will be times when I want to use it saturday, and then again sunday.  Adding a new $400 AC charge controller when I'm already spending the $$ to put the PV on seems redundant, and so I want to use the KID to wall charge. 

does anyone see an issue with using a 120 V wall plug with a full wave bridge rectifier to send 120V DC into the input of the KID?  I could put a fan control on the 120V input if it needs to be ramped up slowly. 
the wall current is solar anyway with 17KW gridtied we aren't lacking. 

I just want to make sure I don't fry anything and don't have to buy redundant chargers. 

Also looking for good solar/electrical puns for name of an electric pontoon boat.     ready: set: GO!
working name is "Queen Ohm's Revenge"

cheers,
karl

Vic

#1
Hi Karl,

There are several problems with your proposed AC charger

The peak DC voltage from the line-connected FWB rectifier is 1.41 X the crest of the sine wave AC input voltage  --  about 170 VDC for 120 VAC input.
EDIT:  An input voltage this high is above the maximum permissible for the KID (162 V MAX,  and the KID will stop operating with voltages above 150 V)<.

Second,  without a transformer to isolate the AC input,  from the input terminals of the KID (or other CC),   there will be NO isolation from the AC line input.   The lack of isolation is a significant safety hazard.

In addition,   it would be good to use a resistor to increase the input impedance of the input current source (the AC line,   and the important input capacitance used as a filter).

And,  so on,   FWIW,   IMO,   etc.  Vic
Off Grid - Sys 1: 2ea SW+ 5548, Surrette 4KS25 1280 AH, 5.25 KW PV, Classic 150,WB, Beta Barcelona, Beta KID
Sys 2: SW+ 5548s, 4KS25s, 5.88 KW PV, 2 ea. Classic 150, WB, HB CC-needs remote Monitoring/Control, site=remote.
 MN Bkrs/Bxs/Combiners. Thanks MN for Great Products/Svc/Support&This Forum!!