12s1p (~45v30ah) leaf LiMnO4 battery charger suggestions?
- Thread starter dcb
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999zip999
100 TW
What's final charge voltage 12x4.2 50.4 volts ? What were you thinking ? I always add a set of sense wire even with bms.
was hoping to use 4v/cell (ok, 4.02) as an approximation of 80% ish charge (good for cycle life), so 48v was the desired termination resting voltage, 4.1v would still be conservative enough for me though, so 49.2 at most if you got it. 115v source. 4.2 is asking for cell degradation IMHO. 1200w max for obvious reasons (assuming reasonable power factor), 200w automatic/adjustable would be fine for the right price.
dogman dan
1 PW
For the ultimate adjustability, and a bit more than 6 amps, go to Grin Technologies for the Satiator.
For a good 5 or 6 amps charger EM3ev has a nice feature. A switch for half charge, 90% charge, or 100% charge. All three voltages can be adjusted, so tell Paul exactly what voltages you want for the two higher charge settings. You could get 80% and 90% for example, or 80% and 100%.
No harm in once in a while going to 100% to balance it best, then discharge immediately.
For a good 5 or 6 amps charger EM3ev has a nice feature. A switch for half charge, 90% charge, or 100% charge. All three voltages can be adjusted, so tell Paul exactly what voltages you want for the two higher charge settings. You could get 80% and 90% for example, or 80% and 100%.
No harm in once in a while going to 100% to balance it best, then discharge immediately.
Thanks for the replies!
fwiw, I dug up some "freddy charger" bits out of the garage for now (manual bottom balanced first).
I'm gonna take a stab at shutting one of these off with a microcontroller or something:
48v, 10a power supply, $50, comically large case for a bike:
http://www.ebay.com/itm/400963671920?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
fwiw, I dug up some "freddy charger" bits out of the garage for now (manual bottom balanced first).
I'm gonna take a stab at shutting one of these off with a microcontroller or something:
48v, 10a power supply, $50, comically large case for a bike:
http://www.ebay.com/itm/400963671920?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
999zip999
100 TW
If you are doing this inside or a garage you have to sit and watch and monitor. Do you have a set of sense wires ? Because of the size you can use an old barbeque if you're going to walk away. Be careful.
I hear ya, the limn2o4 is pretty safe chemistry, mostly don't want to overcharge it because it shortens the lifespan. And I don't leave freddy alone for long.
The 48v supply doesn't have sense wires so it will err on the side of less power to the battery by default. Whatever I sort out to control it can use sense wires.
I'm thinking about using something like this to shut it down at 48v, just to keep it simple, no coding. It has high and low threshold, I think, kind of amusing verbiage:
http://www.ebay.com/itm/12V-Multifunction-Self-lock-Relay-PLC-Cycle-Timer-Module-Delay-Time-Switch-CLOCK-/331650681404?hash=item4d37ebca3c
from there it is either:
add a 12v adapter (always on when plugged in) and bigger relay to shut the whole thing down.
or
open it up, see if it has standby power I can tap, see if I can shut output down with a 10a relay (i.e. pull trim to lowest voltage or something).
It may not like acting like a charger though and I might have to pwm the trim or something to keep the current in limits.
The 48v supply doesn't have sense wires so it will err on the side of less power to the battery by default. Whatever I sort out to control it can use sense wires.
I'm thinking about using something like this to shut it down at 48v, just to keep it simple, no coding. It has high and low threshold, I think, kind of amusing verbiage:
http://www.ebay.com/itm/12V-Multifunction-Self-lock-Relay-PLC-Cycle-Timer-Module-Delay-Time-Switch-CLOCK-/331650681404?hash=item4d37ebca3c
from there it is either:
add a 12v adapter (always on when plugged in) and bigger relay to shut the whole thing down.
or
open it up, see if it has standby power I can tap, see if I can shut output down with a 10a relay (i.e. pull trim to lowest voltage or something).
It may not like acting like a charger though and I might have to pwm the trim or something to keep the current in limits.
dcb said:
did some initial tests with this, have not got the built in current limiting working, so that is a problem, also it cannot stay connected to the pack as-is as it puts a bit of drain on it when not powered by AC, so needs a diode or relay on the output anyway.
Also the build quality was a little scary, but not surprised.
One major caveat, with 10A output, on 120v input the input choke gets really hot, as in starting to smoke, followed by the input rectifier. Everything else stayed pretty cool. I expect it would work better on 240v, but I intend to use 120v for charging, so that kind-of puts the kibosh on using this for ~48v/10A charging on 120v (without a choke/rectifier that can handle the amps @ 120v)
