Mex's Flash?
Does "Flash charging" mean we (some of us anyway) are wrong to hate it when the PowerMax or Iota converters drop their voltages so soon for the absorption stage? In another thread Mex says, "A flas...
Forum Discussion
My observations with a 150 AH Trojan T-1275 that was beat up when I got it free, and I got another 2 years out of it, all on Honda Eu2000i generator time and solar panels, with an Adjustable Voltage MegaWatt 30 amp power supply unit, and an RC watt meter.
I'd pull 35-50 amps a day out of the battery... 60-70 SOC most mornings. RC watt meter told me voltage, and amps the battery was taking and cumulative amps charging.
Usually an hour at 14.8 to an hour and 15 to an hour and 20 was enough to get my amp charge rate to drop to 9 or 10 amps, off from the 29 to 30 amps it would take at first charging for 3 or 4 minutes.
Tiny bubbles after the first 15 or 20 minutes, very, very very tiny bubbles. At an hour to hour 15, when the amps charging rate was 9-10 amps, I shut the generator down. That was it, the end of bulk charging.
150w Solar panel was then employed, usually set at 14.0V. 8.8 Amps was possible from the panel, but more normal was 6 to 6.5 since the panel was portable and aimed almost always at the sun. 2 or 3 hours would drop the amperage down to about 4.5 Amp being taken. At this time, a peek inside would reveal slightly bigger champagne bubbles, a little bit more vigorous. Time to reset the charge controller to 13.6V for the rest of the day on solar.
I always knew that no matter what, my trailer was always drawing 1 AH in parasitic draw, all day long, with nothing on or running.
A week of this, and time to mix things up, charge on the generator first thing in the cold morning at 15.0V, for 2 hours on the generator, a "top" charge and 16.0V with the solar panel for 90 to 150 minutes, for desulphation or equalization charging.
This almost always tuned up the battery, Specific gravity would be 1.275 to 1.280, with the weakest cell, doing 1.250 to 1.260. The T-1275 was an anomaly with this.
This battery saw 500 -600 recharge cycles in a golf cart before I got it. I'd say in 2 years since I got it, at the end, I added 100-120 recharge cycles to it.
With generators, I don't worry about tiny champagne bubbles when recharging at 14.8V. I begin to get concerned when they get soda pop sized like soda water in a clear glass, that's when I try to time it to drop the voltage. That or when the battery won't take something like a c/15 charge rate, or 10 amps on the RC watt meter. Time to go to the solar panel, drop the voltage then and slow the take rate down, letting the battery pass a 90% state of charge without bubbling and a c/15 charge rate for a few hours.
My observation with an RC watt meter is that the take rate in amps will tell you a lot about when to drop the voltage, further dropping the amp take rate. About 9 to 10 amps at 14.8V on a 150 Amp Hour battery with my 30 amp Megawatt was that cut off point, regardless of time on the generator. When it got that low, it was time to cut the generator and go solar. This was with a high 6% antimony sweeper /golf cart battery, that was very beat up. They will bubble, a lot, and they will use water, but a lot less water if you only use voltage and amps as stated, the RC wattmeter, for me, worked almost as well as the acid dip and an SG reading. Taking some regular notes and responses tells one a lot. So does the stench of rotten eggs when a battery is dying, or surprise corrosion that starts growing on the battery terminals all of a sudden, from sulfuric acid off gassing. Of to the recycler it goes, then.
Now I have a Telecom AGM "acid rich" 1.300 SG battery. And a 10 turn pot on the MegaWatt. Voltage sits at 14.4V... and I watch the amps drops that the MegaWatt puts out, while at home, on the grid. When the RC watt meter says .13 Amps for take rate, she's topped off and ready for storage. Usually takes 3 to 4 hours to do this after a 2 week long trip in the travel trailer.
AGM batteries are a whole other world, compared to flooded lead acid batteries, which seem to have huge losses while recharging, due to resistance to charging in the battery.
I'd pull 35-50 amps a day out of the battery... 60-70 SOC most mornings. RC watt meter told me voltage, and amps the battery was taking and cumulative amps charging.
Usually an hour at 14.8 to an hour and 15 to an hour and 20 was enough to get my amp charge rate to drop to 9 or 10 amps, off from the 29 to 30 amps it would take at first charging for 3 or 4 minutes.
Tiny bubbles after the first 15 or 20 minutes, very, very very tiny bubbles. At an hour to hour 15, when the amps charging rate was 9-10 amps, I shut the generator down. That was it, the end of bulk charging.
150w Solar panel was then employed, usually set at 14.0V. 8.8 Amps was possible from the panel, but more normal was 6 to 6.5 since the panel was portable and aimed almost always at the sun. 2 or 3 hours would drop the amperage down to about 4.5 Amp being taken. At this time, a peek inside would reveal slightly bigger champagne bubbles, a little bit more vigorous. Time to reset the charge controller to 13.6V for the rest of the day on solar.
I always knew that no matter what, my trailer was always drawing 1 AH in parasitic draw, all day long, with nothing on or running.
A week of this, and time to mix things up, charge on the generator first thing in the cold morning at 15.0V, for 2 hours on the generator, a "top" charge and 16.0V with the solar panel for 90 to 150 minutes, for desulphation or equalization charging.
This almost always tuned up the battery, Specific gravity would be 1.275 to 1.280, with the weakest cell, doing 1.250 to 1.260. The T-1275 was an anomaly with this.
This battery saw 500 -600 recharge cycles in a golf cart before I got it. I'd say in 2 years since I got it, at the end, I added 100-120 recharge cycles to it.
With generators, I don't worry about tiny champagne bubbles when recharging at 14.8V. I begin to get concerned when they get soda pop sized like soda water in a clear glass, that's when I try to time it to drop the voltage. That or when the battery won't take something like a c/15 charge rate, or 10 amps on the RC watt meter. Time to go to the solar panel, drop the voltage then and slow the take rate down, letting the battery pass a 90% state of charge without bubbling and a c/15 charge rate for a few hours.
My observation with an RC watt meter is that the take rate in amps will tell you a lot about when to drop the voltage, further dropping the amp take rate. About 9 to 10 amps at 14.8V on a 150 Amp Hour battery with my 30 amp Megawatt was that cut off point, regardless of time on the generator. When it got that low, it was time to cut the generator and go solar. This was with a high 6% antimony sweeper /golf cart battery, that was very beat up. They will bubble, a lot, and they will use water, but a lot less water if you only use voltage and amps as stated, the RC wattmeter, for me, worked almost as well as the acid dip and an SG reading. Taking some regular notes and responses tells one a lot. So does the stench of rotten eggs when a battery is dying, or surprise corrosion that starts growing on the battery terminals all of a sudden, from sulfuric acid off gassing. Of to the recycler it goes, then.
Now I have a Telecom AGM "acid rich" 1.300 SG battery. And a 10 turn pot on the MegaWatt. Voltage sits at 14.4V... and I watch the amps drops that the MegaWatt puts out, while at home, on the grid. When the RC watt meter says .13 Amps for take rate, she's topped off and ready for storage. Usually takes 3 to 4 hours to do this after a 2 week long trip in the travel trailer.
AGM batteries are a whole other world, compared to flooded lead acid batteries, which seem to have huge losses while recharging, due to resistance to charging in the battery.
