Charger blew, what is a noob to do?

Hey guys, noob here, just a simple problem and have many questions.

So I have a 90v 13ah battery, it is comprised of two12S 45v 13ah max 65amp discharge Li-NMC in series. Built in BMS, each pack has a charge cable; it came with two chargers, one for each 12S pack, charger label reads 50.4v 5amp.

http://www.hi-powercycles.com/90v-13ah-hpc-elite-90v-13ah-li-nmc-ultra-high-performance-battery/

So one of them blew, strong burnt smell inside it, I heard a loud pop and crackle and unplugged it, one charger was hot, the blown one. So now I only have one charger, can I continue to charge the 2 packs connected in series, one pack at a time? The battery is connected to a controller and to CA v2.3.

Any idea where I can buy a replacement, other than HPC. I was thinking bmsbattery, I understand I can specify the voltage and current, so which charger wattage do I go with, just enough for 50.4v x 5amp?
http://www.bmsbattery.com/37-ebike-charger

And speaking of charging, what is the optimal charge current for long battery life? And how does one optimally charge the battery to enable the BMS to balance the individual cells. Do I charge it till the charger turns off and leave it for a while longer, or is it ok to just charge to 4.1v. I asked HPC, they said the battery BMS will balance while charging, and didn't specify any necessary procedures.

Thanks all.

Shipping from bmsbattery is high, order 2 400W chargers set for 6A @50.4V. Keep the original for a spare.
i have no idea how the bms they use works, but most balance at top charge and may need to be left on charger longer if they get out of balance.
For as much as they charge for that battery pack, it should come with a 5 year warranty on the chargers. I hope you got the regular 2A chargers. They really rip you off to upgrade to 6A chargers. I think they sell on the P.T. Barnum principle. A 13ah 24s pack shouldn't cost $2K. That's ~$1.75 per wh. That's almost 6 times what I paid for my 24s pack. I've got over 8K miles on mine and expect at least 12K before replacing it. Hope you can get at least 30K miles out of that one, but to be honest I doubt you'll get any more than I do..

Did you connect both chargers while the batteries were still connected in series? You can't do that because the chargers have a common ground, but the batteries don't.

open the charger so we can see what blew up. the screws are usually under the rubber pads used for feet around the corners.

you were misinformed about how the BMS balances the pack. the BMS can only balance the pack when it reaches the balancing voltage which is 4.20V.

wesnewell, I bought it used for well under that, it came with the complete bike and motor/controller etc.. It came with a 5amp charger, which incidentally they don't sell anymore (they sell 2,4,6amp chargers now). When I got this relatively new used system, the charger would crackle at the end of charge only when I disconnected the batteries while the charger was connected to the wall.What is the reason to recommend buying a 6A vs 4A or 2A aside from faster charge?

I connected both chargers to the batteries (one charger on each battery) and charged them while in series and connected to the controller and CAv2.3, it's just plug and go. That's what the manual says to do, or at least, the manual didn't say not to do that and the 'system' came with 2 charges with the charge ends shrink wrapped together (4 Anderson pole plugs).

dnmun, I will open it up and take a picture later in the day and post it. As for the BMS balancing, how long do I leave it at max voltage (4.2v) for? I assume the charger should be cycling itself on and off if it were to be balancing?

Until I get a new charger(s), how do I go about charging with one charger, do I have the take the pack out of series? Or can I just plug it in to one battery and then the other?

once we see inside we can tell you if the outputs are isolated. usually these little SMPS chargers using the mosfets for switching blow the ICL inrush current limiter that slows the current surge when it is turned on. it will be obvious.

12S limno2 is 50.4V fully charged. you can charge each pack individually if you need to.

dnmun, with the one charger, do I charge each pack individually while still connected in series, or do I have to break the series?

looks bad. these are kingpan chargers, you need to replace the two npn switching transistors and the 2 ohm base power resistor that blew up. lemme know if you need the parts.

you also can use a 48V meanwell power supply in series with that charger to get up to the 100.8V and then rewire it with a 24Ss lipo BMS to cover both of those individual packs so they perform as one.

So on these Lithium Ni Manganese batteries a LiFePo or a LiIon charger can be used??? There's a 10amp LiFePo on ebay that I'd consider using on my Leaf batteries, which are LiMnO2 (or LiMn2O4--I flunked chemistry three times in college...). Would that charger work to good advantage on the Leafs????

the chargers have an optimal range the transformer is designed to cover so select a charger close in voltage to where you want to end up and then you can adjust the final endpoint by adjusting the trim pot or if you have to have them do it they will adjust the final voltage for you usually.

Exe I have two 12s as 24s I charge with 2 charges, but unplug the pos. connection. I have charged one pack then the other, with pos. Unpluged or one pack at a time. Now the pos. is unpluged from batt.- controller. I think just as long as not drawing current. Maybe an expert will chime in. The bms 400 watt charger sounds good on paper.

thanks dnmun. so it's all about voltage, and I gather final voltage, and the chemistry requirements of the many types of Li batteries are pretty much the same.