60V charger for 40AH LiFeP04 pack.... please help

Go to this company and check out the chargers. I have TS in 48v pack. I use the 48-15Amp charger that was $165. It ends the voltage at 58.2 volts. Or look at the other models for your needs. I have needed no BMS as the charger slightly undercharges the TS cells--perfect: http://elitepowersolutions.com/products/product_info.php?cPath=9&products_id=63

Hmmm, I just saw you have 18 cells--that's kind of an odd number...

Jeff K.

I have been using lead acid batterys because of cost of LI, and the charge discharge/cycle life problems. The batterys have to be well balanced as to their capacity in their pack, as the other poster stated it is best to slightly under charge for longer cycle life- On another forum a LI user killed his batterys in a short time by drawing more than their rated current rating in not many cycles- wrong use causes the growth of crystals that lead to a internal short.

The best chargers that I have read about use a by pass system when the single cell reaches the maxium allowable voltage, as to not over charge that cell in the string. In order to accomplish this the chargeing system has a voltage monitor connected across each individual cell that will, in this case connect a device across the cell when it has reached it's fully charged voltage, to shunt around the current until the correct chargeing voltage in string is reached, before turning off.

As to each cell, over charge fatal, cycle to below recommended voltage fatal, or at least the cycle life will be reduced to a few hundred cycles, as to the optmum charge/discharge cycle up to around 3000 cycles. The recomended storage and shipping voltage is around one half charge.

With the cost of your 40AH pack I would invest in the charger that will give the maxum life of your batteries even if it costs in the hundreds of $. Make shure that your controller (to motor) will do a low voltage cut off, or have a digital volt meter to look at to allow you to not discharge below the 3V~? X (number of cells) or what the total recommended voltage is for the pack.

My 2 Cents worth, jeb

Gday Wheelie,

good to see a fellow aussie on the forums :D
which part of Australia you from? Perth myself.

i have a 15cell 40AH TS pack on my emax.
i charge it with this charger:
http://cgi.ebay.com.au/Lead-Acid-Battery-Charger-10Amp-48Vdc-230Vac-New_W0QQitemZ400017065841QQihZ027QQcategoryZ50603QQtcZphotoQ...

and this BMS:
http://www.evpower.com.au/-Thundersky-Battery-Balancing-System-.html

a few things to note,
for true 60v, you need 20cells.
18cells will only give you 54v at 40A, whereas 5xagm 12v batteries would give you a fulll 60v under load.
i found this out the hard way, and had to add a second set of cells of get ym top sped back above 60kmh.

as far as charge voltage goes, it just has to be between 3.4v and 4.2v until curent falls below 0.1A.
testing on my dumy load puts the difference in discharge capacity between 4.2v and 3.4v at 0.5AH.

on my scooter i charge to 3.89vpc until current falls below 2A.

Matt

PS. do you have an evablum page?
mine is here: http://www.evalbum.com/1499