Best Of
Re: Victron disconnect quirk causing temperature sensor failure?
Saipro
Re: Retired, Want to Go Off Grid Because of High Cost of Electricity
NANOcontrol
Grounding
sandebagger2u
Fridge is surge overloading 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
Dave Angelini
Re: Solar Generator batteries losing battery charge
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