Thread: Problems powering notepad with UPS in cabin

Thank you once again Fraser. Your assistance and shared knowledge is much appreciated.
Well the DC adaptor finally shut down power from the little Honda battery after 8 hours and 20 minutes of continuous operation. That seems quite acceptible considering the small size of the battery, which still gave a voltage reading upon shutdown of 12.13 volts. More than enough to restart the car. The highest state of charge I have acheived today with the afore mentioned single 12 volt 100AH battery is 12.20 volts after 3 hours on the alternator. Perhaps it has developed a memory due to never being fully charged for the past couple of years? When this battery was connected to the Ritmo DC adaptor previously, it shut down after 2 hours at a much lower voltage reading (10 volts), so could it be that amps rather than voltage is the factor that determins when shutdown occurrs? Bill.

The alternator will charge your batteries quite happily if its set up correctly

using engine rev drop/raise to measure if you've charged your batteries is a bad idea as you're basically dropping the batteries off charge when they've just finished taking in a bulk charge (which is usually said and done by about 70%soc) after that point the amps that a battery will pull out of an alternator drops off but they still are accepting a charge from the alternator.

my field method for checking the batterys charge rate is with a bank of lights ranging from 21w up to about 60w if the alternators charge cable is cool enough for me to grab by hand I just drop the lights in series with the alternator and the batteries if the lights dont glow I go to the next one down.

a better way of doing it is with an induction amp meter or a clamp meter similar to 400A AC/DC Clampmeter - Jaycar Electronics

with the size of the bank you're running you could happily run 200A alternator or run a series of alternators in parrallel.

Originally Posted by Blknight.aus

The alternator will charge your batteries quite happily if its set up correctly

using engine rev drop/raise to measure if you've charged your batteries is a bad idea.

Thanks Dave. To be honest it's not something I have done more than on a couple of occasions, and only since using the smaller engine, when I noticed , due to noise and engine revs that the engine was no longer working hard.
Bill.

Bill, lead-acid batteries don't have a "memory" as such, but they really, really don't cope with being stored in any condition other than fully charged.
If only you were closer I'd be happy for you to drop them off here a pair at a time, and give them a proper full charge, then check the voltage on them after letting them sit for a day....I suspect you may have a dead cell or two in each pair, or they are just not getting enough time on the charger to get there, or the alternator's regulator voltage is too low.
Is there any chance you can take them somewhere with mains and use a good charger to give them an "equalising" charge, then let them sit for a day,m then check their voltages? You might be just flogging a dead horse at this stage.
Is the meter you are using to measure them fairly accurate?
As Dave said, the charging current drops off well before the battery is full, and unfortunately, it just takes time to get there.
On another note, you can get this sort of thing to use with your alternator, and it will give you feedback as to where your batteries are, and protect your alternator.
Hmmmmmmm

Fraser

Fraser, I'll take a pair to a mates place down on the highway a bit. He's on the grid and we can give them a charge and test them after 24 hours.I think the regulator on the alternator is allowing full charge because when i plug a flattish deep cycle battery on to it the engine loads up significantly and will stall if i don't have it on at least 3/4 throttle for a while.

Meanwhile, The Ritmo adaptor has turned out to be a hunk of Chinese junk.It has flattened another but slightly larger 13 volt automotive battery in 2 hours, and the adaptor itself has got quite warm compared to the Power Tech version.
Bill.

See you have that keyboard sorted out Bill

Originally Posted by wagoo

Fraser, I'll take a pair to a mates place down on the highway a bit. He's on the grid and we can give them a charge and test them after 24 hours.I think the regulator on the alternator is allowing full charge because when i plug a flattish deep cycle battery on to it the engine loads up significantly and will stall if i don't have it on at least 3/4 throttle for a while.

Meanwhile, The Ritmo adaptor has turned out to be a hunk of Chinese junk.It has flattened another but slightly larger 13 volt automotive battery in 2 hours, and the adaptor itself has got quite warm compared to the Power Tech version.
Bill.

Good to know, I'll not buy one of those if I ever need another...My older Powertech gets slightly (only just noticeable) warm when running my laptop and charging it's battery.

Originally Posted by Bearman

See you have that keyboard sorted out Bill

Yes, a 30 dollar keyboard from officeworks fixed the problem.If only my power supply issues were so cheap and easy to sort out.
Bill.