Gottahavit! Gottahavit!

[BernieQ2]

Thanks Terry. Now I know.
Bernie

[Wilbor]

Whirlpool make cars

[T1 Terry]

Whirlpool make cars

Do any of the brand names actually make their MPPT controllers?

[John M]

I can only agree with T1 we played around with MPPT for over 4 years trying three different brands and at the end of the day settled on a $30 eBay special, which charges the batteries with no problems I have 4 x 120w panels on the roof feeding 4 x 105ah fullriver batteries, the main problems that were encountered with the MPPT regs was that they would drop into absorption mode early in the day (probably due to the fridge cycling) and even though the normal fridge cycles, and daytime usage, the level of charge didn't drop enough to bring the charger back to boost charge, consequently the batteries were never fully charged. I almost never saw much more than 10a input, since changing to the PWM regulator set to 14.2v, I can see the full 30a input, though rarely unless I deliberately bring the batteries back to 50% soc by using the inverter to run a 240v electric heater (1200 w) for a couple of hours, and then the batteries are fully charged by the end of a couple of days.

[T1 Terry]

An interesting result today when trialling the CTek D250S dual and smart pass to see if they operated and just how well they operated. First trial was a 12v AGM battery with a resting voltage of 12.75v. The Solar side of the D250S got up to 11amps but rapidly faded away to 3 to 4 amps. I attached a 40 amp charger to simulate an alternator charging, back to the 11 amps, but that was it. Duplicated the test on the alternator connection, identical results, but, when I disconnected the mains charger, the D250S started charging the AGM battery from the Li house batteries. 17v at the CTek terminals and 14.4v at the AGM. In fairness, these units are designed for lead acid batteries so anything that remains above 12.8v when the charging transfer starts must have an external charging source attached and as it's above 12.8v it must be fully charged. In this case, 12.8v would represent an almost fully discharged Li battery, so the alternator connection will not be suitable for that purpose.
Next was a 100w folding solar panel, on the solar connection, after 5 mins of fart arsing around running the amps up and down, it settled on between 4.23 amps and 3.89 amps, the MPPT could not hold a steady output. Next tried it on the alternator input, 4.56 amps to 4.23 amps better than the solar, rechecked it on the solar thinking it was possible a better sun angle as around 10 mins had passed, same reading as before and again, started at 0 amps and stuffed around climbing 0.5 amps and back to nothing and so on till it got back to the 4 amps, give or take .25 amps.
Next I tried it on the smart pass, this is basically an 80 amp relay that simply switches straight through to the battery, instant 4.78 amps and climbed to 5.28 amps. Battery voltage remained at 13.4v through all the tests, the reading were from the Victron 600s BMV.5.28 amp x 13.4v = 70.75w, 70% output from a 100w panel. The CTEK 250S got quite warm while trying to extract less than a direct connection could achieve, no doubt that is why there was a lower current flow to the battery, it was using part of the generated energy to power the MPPT circuit. The solar panel remained connected to the Smart Pass for the rest of the day but I tried using the link to the alternator feed on the D250S, an immediate drop in current going to the battery and floating up and down, the same with a link to the solar connection, so I left it connected to the smart pass with the load feed on the smart pass linked to the solar side of the of the D250S for the next hr. The Smart pass remained cool to the touch, the D250S was quite warm to the touch. Disconnected the solar link so only the Smart pass had the solar, the current immediately went back up.
I'll use the MPPT boost feature of the D250S solar side for the alternator charging, the solar will feed via the Smart Pass. The results are similar to previous tests with other brand MPPT controllers, they are a step backwards when it comes to charging Li batteries.

T1 Terry

[Greynomad]

When I had some electrical work done on Girt last year, the company was Springers Solar in Brisbane.
They moved my Solar controller from an under-floor bin (useless location - remember the saga?) to inside, and upgraded me to a Dingo controller. (Also upgraded my deceased 1500W inverter to a 2000W unit.)
I asked about the advantages/disadvantages of an MPPT device, and was told, "Nah, ya don't want one o' them... useless in this installation."

Good that they were so honest. And fair with their pricing, too.