Grid-Tied Discharger

[magudaman]

Not sure if anyone has talked about this yet or tried it but my searches came back negative.

I am tired of resistive type dischargers and was interest in trying a grid tied one. Those cheap, illegal, Chinese grid tied inverters have all over ebay for quite some time now and could make a really cool loading device for testing batteries. They have MPPT would could pose a problem and control of course in general would be a challenge. You can acquire a 1000w unit for around $200 bucks. 24v to 60v, 65 amps. Island protection.

 

[wb9k]

Cheap inverters are just not worth messing with, IMO. We've used Outback units here for grid-tied discharge/cycling with success, and most of the big battery cyclers we use (Aerovirionment) have grid ties built in. None of those are cheap though.

Another option is just to use an inverter to power stuff around your shop until the battery is depleted. This assumes you don't really care about controlling the discharge rate, as long as it's safe--better for scrapping and that sort of thing. I use this method quite a bit. Decent inverters have come way down in price in recent years. I'm presently using a GoPower! 300W pure sine unit I bought for $171 on Amazon. Impressive build quality and performance. I've blown up more cheap inverters than I can shake a stick at. No more, unless they come to me for virtually no money. That goes double for anything with an intertie feature.

 

[heathyoung]

Interesting idea - you can get a cheap 2.5kw inverter (transformer type - eg boat anchor) from eBay new - actually approved for connection, but no one uses them because they are a pain to mount on the wall - and the company importing them went bust (inspire solar) so no warantee - as low as $150 - brand new.

Mppt would just keep loading the battery to keep a constant power output. Hmmmm....