Charging LiFePO4 - 2A vs. 5A
- Thread starter drasp
- Start date
dogman dan
1 PW
It's cheaper to give away a free charger when it's a 2 amp, maybe costs 15 bucks wholesale charger. The Pingbattery, v1 and v2 bms can handle 5 amps of charging current. I do half my charging with a 4 amp sla charger to speed things up when charging at work. For a 20 ah battery, 5 amps is .25 c , so it should be plenty safe for the battery. Go for the 5 amp if you have a choice.
Way cool. Same situation as you - I need to charge after a ride to work & its a drag to do half the battery at 2A. Will probably score a 5A charger from Cammy HERE & see if the BMS in my E-Bikekit.com LiFePO4 pack likes it. . . I was thinking the same thing re: .25C charge rate - it seems like it'd be plenty safe on the cells. 
BTW - anyone using the above 5A charger?
BTW - anyone using the above 5A charger?
dogman dan
1 PW
Don't know of any that are on the signalab bms. You could of course, do a partial charge bypassing the bms at a higher amp rate. Then use the smaller charger to finish off the balancing. It makes sense to me that up to 1c charging would do no more harm than 1 c discharging. The main reason not to do it is the price of a high amp charger. If you didn't turn it off in time, you'd roast the battery of course.
dnmun
1 PW
you can buy 500W power supplies from ecrazyman. i wanna get the 48V 12A version, i think it is 15A for 36V. also there are a lot of power supplies on sale on ebay. i bot two 48V power supplies for $30 total, 10A each. but they weigh 40 lbs. keywin's power supplies are switchers so they are lighter so you may be able to carry them with you. my next thing to buy.
Yes, I used it for a few cycles and it is still working. Much larger, heavier and put together better than the 2 amp charger that he was shipping with his batteries. I haven't opened it up for a peek but it seems to be well made. Fan works well as it doesn't get very warm.drasp said:
Although his webpage states an output of 45 volts it is closer to 46.5
dogman dan
1 PW
I miss read that, I was thinking is anybody charging at above 5 amps? 
BatteryMooch
10 kW
I regularly charge my LiFePO4 packs at 10A and know of several others (R/C fliers) who charge at MUCH higher levels, up to 100A. None have reported a reduction in cycle life but I'm sure at some of those really crazy high charging current levels that the cycle life is reduced.
miro13car
100 kW
I charge mine LifeBatt grey cell HPS BATTERY at 10A with Soneil charger.
Grey LB/BMI cells are rated 30A for charging.
Everthing depend what yours cells rating for charging.
MC
Grey LB/BMI cells are rated 30A for charging.
Everthing depend what yours cells rating for charging.
MC
recumbent
100 kW
miro13car said:
Hey Miroslaw, Do you know of a good supplier of Soneil chargers here in Canada?
Marty
Eric G
1 kW
There's Econogics in Napean Ontario...
http://www.econogics.com/
I've never ordered anything from them but Soneil International lists them as a qualified vendor.
Eric
http://www.econogics.com/
I've never ordered anything from them but Soneil International lists them as a qualified vendor.
Eric
dogman dan
1 PW
At risk of harping on it, Lifepo4 charges just fine with just about any sla charger that shuts itself off. If you are discharging at a reasonable rate, you should only need a real balancing charge occasionally. So you could find any charger you like and do most of the charging with it, and just finish off with the one that reaches the higher voltage as needed. My own practice is to use a 45v 4 amp charger to get a 5 hour charge at work, and then use a 47 v 2 amp charger at night. So I get a balance every other cycle. Last summer I did 100 or more cycles with nothing but 45 v chargers and never got out of balance. Once you ride to cut out, I find it may be time to be sure to get some balancing charges, but if you leave enough in, the pack may stay more balanced.
I think people obsess too much about balancing, and not enough about discharge rate and depth of discharge. Those are the two reasons the pack gets out of balance, and a well matched motor and battery leads to less needing to balance.
I think people obsess too much about balancing, and not enough about discharge rate and depth of discharge. Those are the two reasons the pack gets out of balance, and a well matched motor and battery leads to less needing to balance.
recumbent
100 kW
Eric G said:
Thanks Eric, I've contacted Darryl at Econogics and everything is moving forward.
Soneil says the charger is rated for 6amps but charges like a 12amp heavy transformer in charge time. I like that
sounds too good to be true, but I'm getting one just the same.Dogman is right about using quality sla chargers for LIFEPO4, the Soneil graphs show a correct charge pattern listed on thier site.
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