Best Of

Re: Retired, Want to Go Off Grid Because of High Cost of Electricity

Try looking into Home Nuclear.

Grounding

No solar. 15 amp shore or generator to run Genius2 which charges battery(s). Should shore connection be grounded to frame? Should inverter be grounded to frame? Should leisure battery be grounded to frame? When shore available, separate outlets available to run TV etc. If grounded to frame it would be only connection to DC system.

sandebagger2u

Fridge is surge overloading inverter

Yeah, just like it says, when the fridge kicks on, my inverter sometimes goes into an errored state and needs to be turned off in order to recover. The inverter is rated at a constant 1000w and can surge to 2000w. The load on it when the fridge is running is only at 200w, so I'm guessing it's surging over 1800w to cause the tripped inverter.

I need to come up with a plan around this error. What I have in mind is getting a UPS for a computer which has a battery backup in it good for 30 mins. When the fridge first kicks on, I want it to utilize the juice inside the UPS for its surge instead of the inverter. Anyone have any suggestions on which ones do this? I know not all UPS's allow you take a pull off the batteries if it has power coming in. Or maybe there's a better idea someone has to work around this issue?

flighthouse

Dipping my toe into solar energy.

Hi all.Been lurking for awhile.This site is a wealth of info.I have a small system that's been running about a year and a half.So far so good.I have 4 100watt panels wired in parallel feeding Tristar 45 charging 2 12 volt 50 AH agm batteries wired in parallel. A suresine 300 watt inverter gets some use.I now know these batteries should be 6 volt wired in series.I use max 500WH in the summer and almost nothing in winter--3 led lights and occasionally a trickle charger for lawn mower battery.Looks like I have enough charging capacity to upgrade to 6 volt 225 AH batteries.A couple days last summer my batteries got down to 12.2 volts--the reason for battery upgrade.Will my system work year round?.Do I have to exercise the batteries during winter or will they be happy just sitting with almost no DOD other than self discharge? I'm at 42 degrees latitude and the panels are angled at 22 degrees--roof pitch.I know the angle isn't good for winter but it is ok for summer when most of the energy will be used.I'm running a 12 volt cooler that uses 464 WH per day--manufacturer's number, not measured and 3 10 watt led lights,sometimes a small radio and a phone charger.If all goes well we would like to build a larger system.Thanks in advance for all opinions.

cheers kent

Kenth

Re: PWM that can 24v(28+v) input with 12v(14+v) output

Generally, if your panels are "12 volt" rated (Vmp~17,5-18,5) volts, that is the "accepted" standard for connecting a PWM controller to a 12 volt Lead Acid battery bank.

Long wiring (too small of diameter), very hot weather with cool battery bank, etc. (Vmp falls as temperature rise, Lead Acid battery charging voltage rises as they get cold) and the voltage drop from hot panels / long wire run from array to cool battery bank (higher voltages needed)--You can run into reduced charging current in Hot weather.

In cold weather, Vmp-array rises--But for a PWM controller that "extra/free" energy (power=Voltage*Current, rising V = rising available power) is lost.

A MPPT based charge controller is like an automatic transmission between the solar array and battery bank. It can run the solar array at "optimum Vmp and Imp" and charge the battery bank at "optimum Vbatt and Ibatt".

If, for example, you put 2x "12 volt" panels in series with an MPPT charge controller, then in Hot Weather, Vmp-array-hot is still way higher voltage than you need to charge/equalize your battery bank. And in subfreezing weather, the increase in Vmp-array (~10-20% increase in voltage), the MPPT controller can supply that "extra free power" to the battery bank charging/running your loads).

In the old days when solar panels were over $10 a Watt and golf cart batteries--Optimizing a system to save on solar panel costs made sense.

Today, batteries are 2x or more expensive, and solar panels (large wattage) less than $1 per Watt... So optimizing the battery charging/loading conditions for longer battery life makes sense--And throwing cheap panels at your system to keep your expensive batteries "happy" makes sense today.

-Bill

BB.

Re: Wildfires are nice for Solar Business

Definitely, I forgot that... Ever have a Skycrane land near your house? One had an emergency a few years back and came down in a clearing near our place. By the way CDF is still there but called CAL FIRE now.

Dave Angelini

Re: Solar Generator batteries losing battery charge

Get some sun on the panels and see if they accept a charge, a DC clamp on ammeter would be helpful to diagnose if there is a potential problem, I wouldn't rely on a battery monitor.

mcgivor

Re: High Specific Gravity Unexplained

Ako, Thanks for providing the Float and early Bulk SGs.

There is more variation in the SGs than I would have guessed. AND, for those measurements, it seems that your high SG situation, is not as extreme, as you noted before -- perhaps some of your changes to the charge parameters are helping (?),

If this were my battery bank, would try to discharge it deeper than normal -- to about 65-ish percent SOC. Watch the voltage on the second battery in the table (the one with the lowest SG cell), or the SG of that battery/cell during the discharge. Deep-cycle batteries DO like to be cycled relatively deeply, on occasion.

After this discharge, fully charge the bank, and EQ it in the lower range of the recommended EQ voltage, if possible with the TS-60. Would recommend trying to recharge the battery immediately after this discharge, as letting a fairly deeply-discharged battery sit, off-charge is not the best thing to do.

If you could try charging only that battery with a 6 V charger, that might be even better. If doing this, the output of that charger must not have its output connected to the safety ground, or either AC input connection ... am not certain where you are located, and the standards used for safety grounding, and weather the battery has a connection to any safety ground in your system. If you have a 6 V charger, you could quite possibly charge this lagging battery while the system is running in Float. This might be an adventure that you might not want to try.

FWIW, just some opinions, Vic

Vic

Re: old battery safety/using a car battery temporarily

thanks Estragon. Will check with the compatibility with the auto sparky I will prob get a secondhand battery from too.

"Running the pump from a battery charger without a battery may damage the pump."

BB, I'm not talking about running the pump from the charger (not even sure how I would do that). I'm talking about charging a car battery and running the pump off that. I've done that before with lights and a car radio, just wasn't sure if it would work/be ok with a water pump.

leaf

Thanks to BB Bill !

This is not really in the weeds;

Just want to say a public Thank You to BB Bill for ALL that he does here -- much of those efforts are behind the scenes, but very much for the good of the community.

Of course Bill is very, very helpful in giving Engineering-based advice, that we all can see, and admire!

Thanks, too, to Northern Arizona Wind & Sun for hosting this great, and informative Forum, and also for being an honest, well informed Customer Friendly company to deal with.

Thanks ALL! Vic

Vic