MPPT vs. Tycon Charge Controller for 70W system

[georgemiller]

Dear Forum,

In my setup only have space for a 70W flexible panel and am attempting to maximize output from this small thing (I don't mind spending lots to do so). I have two possible options for charge controller:

1) Tycon Solar Charge Controller (Full specs attached as PDF)

2) Gensun MPPT

How much efficiency am I losing by going with the Tycon, as opposed to the Gensun? The Tycon is useful as it includes power over ethernet output. If we went with the Gensun, I'd also need to buy a dual POE output injector, which isn't that big of a deal. The most most important thing is efficiency. Any thoughts?

Thank you very much!
George

[Mike90250]

Not knowing anythign about the 2 models you offer for compairson, I'll add my own idea to the mix, Morningstar Solar Sunsaver MPPT
https://www.morningstarcorp.com/products/sunsaver-mppt/ it's a solid performer.

The PoE controller you mention has this on page 5
6. When charge from DC, as the battery full, the CHA light will off, if the CHA is always
light, that means the input wattage lower than the required minimum wattage.
The minimum input is 3 Amps at input voltage is 18V.

Since the controller has a 10A max input, you have a small window of usefulness. I worry that the efficiency of the electronics is not good, and the device can use a lot more power than you expect. And it's a PWM controller. Without the specs for your panel, I don't know what the power mismatch is.

[georgemiller]

Cheers Mike. The morningstar products are great. I'll take your advice and swap the Sunsaver for the Gensun.

Specs for the current panel I have in place (only 50W now, upgrading to a 70W panel once I find a good quality one):
*Optimal power [Pmax]: 50W
*Working voltage [Vmp]: 18V
*Working current [Imp]: 2.7A
*Short-circuit current [Isc]: 2.9A
*Open-circuit voltage [Voc]: 20V

Amazon link: https://www.amazon.com/ALLPOWERS-Cha...ct_top?ie=UTF8

Does this help give you an idea what I'm losing from the Tycon vs. the Sunsaver? Fwiw, the Tycon has a fairly low self-consumption.

George

[Mike90250]

with 18V panels and 12V battery, MPPT will yield little gain. UNLESS the panels are going to be mounted remotely and with long cable runs to the controller & battery.

but FIRST you need to get the Tycon, measure it's power consumption while powering all your ethernet gear and see what size battery you need to power your loads for 3 days of no good sun.

a big battery and a small 70w panel is a recipe for failure. I don't see many cases where a 70w panel is useful for much .

[georgemiller]

Cheers for the response Mike. I should have specified a bit more, it's a Lithium Iron Phospate (LiFePO4) and the nominal is 12.8. But I don't think that is enough to change your calculations. So PWM it is!

I wish I could use a larger panel, but I'm mounting this on top of a construction crane and there's really not much space. I may push it to 100W but that's about all I can do. The draw is about 18W/hr (Axis IP camera and a Ubnt radio) and the unit is on about 10 hrs day. I expect it will deliver insufficient power around 10-20% of the time. Alas

[Mike90250]

if you are using a LFP battery, you need to have a charge controller that can be aware of it's state of charge, or a BMS that can handle the entire charge current in its shunts