Matthew E's posts

I've got a Xantrex MPPT charge controller (60A) in my off-grid system, and recently in the mornings as the sun rises, the output readings are much lower than expected.  I've found that if I switch my PV array breaker off, and then on again, that the output readings jump to the Wattage I would expect, continuing to climb during the day as expected.  I've found that if I switch "off" all of my loads on the batteries overnight, this problem does not happen in the morning. Any ideas why?  I don't want to have to be switching the breaker every morning!

I have a 12V battery bank, with two 100Ah AGM batteries, and two 200Ah AGM batteries.  Is this advisable, or should they all be the same size? (I've been told the latter) Should the bigger batteries be on the outside ends of my parallel string?

Thanks Ken.  Actually I totally agree with you about the energy wastage.  I'd definitely prefer going with the diversion controller setup, in order to NOT waste all that extra energy (and also to have hot water in the jungle for those cool rainy days). That's one reason why I haven't bought the manufacturer's shunt-type charge controller for the hydro.  Using the diversion controller setup, I'm just nervous about whether the unregulated hydro power input will fry my batteries...or shorten their life--you know, the "bulls of Pamplona" .

Thanks, Ken.  That fits with what the distributor for the mini hydro says.  I'm curious, has anyone else tried a different setup, or found a different charge controller capable of handling this kind of load?  This system is for a jungle outpost which may be vacant for weeks or months at times, so I'm still interested in the possibilities for a charge controller and not just a diversion load controller. It seems like there are so many choices out there for PV controllers, but when it comes to wind & water turbines, each unit just has its own proprietary controller.  If you don't like it, what other choice do you have?

Oh well, looks like you really have to yank up on the little lever to release the wire (especially when you've put a slightly oversize wire in it)! ;o) Thankfully it didn't go to pieces though. 

I'm wondering if someone can explain to me how to connect my wires to the Xantrex MPPT 60 auxiliary output.  The manual is not helpful.  There's 2 small holes in a plastic housing, one for - and one for + of course.  Then there's a little plastic lever above each hole.  I inserted a piece of solid 12AWG wire just to check its function, and it seems to have a spring-loaded catch inside.  Now I can't get the wire back out!  And the little levers seem pretty flimsy.  Pulling up or down on them doesn't free the wire, and the housing threatens to go to pieces.  How does this thing release? Thanks, Matt

Thanks for the reply.  I was thinking of using the Xantrex C series as a diversion controller, but the manufacturer of the hydro warns that the voltage produced by the hydro is too high for unregulated direct connection to batteries and may cause battery damage.  (Also wondering if my inverter will shut down due to high voltage input, being also connected to that battery bank on the same terminals.)  Others have said they direct-connect these hydros without any problems.  What do you think?

Hi, I'm trying out a new Ampair UW100 submersible hydro (12V, up to 8.3A), and not impressed with the manufacturer's charge controller since the set points are not customizable and when batteries are full I'm just wasting power since it's just a shunt-type charge controller.  Does anyone have advice on a different charge controller I could use, preferably one which doesn't have the problems mentioned above (ideally one which can regulate charging AND divert power to a dump load such as a hot water heater element when the batteries are full)?  The controller must be able to handle up to 47VDC input, since that's the max no-load voltage produced by this hydro.  Normal voltage with load is 18-20VDC, up to 8.3A.  Thanks for input,
Matt

I'm setting up a system with Haze AGM batteries and an Ampair mini hydro (UW100).  Unfortunately the only charge controller produced and recommended by Ampair for their hydro is set to automatically periodically give an equalization charge of 14.4V to the batteries (this function can not be disabled).  My Haze documentation states that the max charge for their batteries is 14.4V.  Will this periodic equalization charge harm my batteries?  I know AGM batteries are not supposed to be equalized, but that's the only charge controller designed for my hydro, and the voltage IS within the max specs for the batteries.  What do you think?