Charging 12S lipo

[RC_guy]

Hi guys,
Sorry for asking what has been asked probably many times but I'm all confused
My ebike has 12S 3P 5000mha pack. I paralleled all my balance leads from each 6S 3P into 1 and my 2x 6S 3P are connected in series. I use a 12S capable charger so I just need to plug my 2 main battery leads and 2 ballance leads et voilà!

The problem is that I have blown 2 chargers doing this after 1 year or less of use. It seems that these chargers are not meant to charge such big batteries even if their input voltage is above say 23-24V they really heat up.
-How the heck do you do it with a regular PSU?
-You probably absolutely need a BMS? Or could I just balance once in a while?
-Can you adjust final voltage easily? I like to charge at 4.16V but when going on long rides I will take them up to 4.2V

Thank,

 

[RC_guy]

Hi guys,
Sorry for asking what has been asked probably many times but I'm all confused
My ebike has 12S 3P 5000mha pack. I paralleled all my balance leads from each 6S 3P into 1 and my 2x 6S 3P are connected in series. I use a 12S capable charger so I just need to plug my 2 main battery leads and 2 ballance leads et voilà!

The problem is that I have blown 2 chargers doing this after 1 year or less of use. It seems that these chargers are not meant to charge such big batteries even if their input voltage is above say 23-24V they really heat up.
-How the heck do you do it with a regular PSU?
-You probably absolutely need a BMS? Or could I just balance once in a while?
-Can you adjust final voltage easily? I like to charge at 4.16V but when going on long rides I will take them up to 4.2V

Thank,

 

[docnjoj]

I use a Thunder 1220 and charge both and A123 12S pack and a Multisport 16000x 12S pack with no problems. I use 2x6S connectors on each battery set up in series. No problems. I do keep the charging amps to 5 and will only test D/c at 2 amps or less.
otherDoc

 

[dogman dan]

Yeah, you may be just wearing out a charger, simply by running it continuously a bit longer than the designers really built it for. Lowering the amps could help, but then it just takes forever.

To keep using that type charger, better cooling for it might work. But then it becomes a bit of a kludge, some big fan stuck on it.

After a few years of mostly just bulk charging my lipo, rarely needing to use the balancing function, I just went to the right voltage to work well with my existing lithium chargers. One is an old 48v ping battery charger, the kingpan type. Voltage can be adjusted enough to use it for 13s or 14s. Not sure if it can go to 12s voltage, but I think it likely can.

So I run 14s, and charge to around 58v. My favorite charger is one I got from EM3ev. It has a three way switch. One charges it half way for storage, the middle is set to 4.1v, and the third to 4.2v. Those can be adjusted some too, So my 14s full charge is still only 4.15v.

The gold standard charger now, is definitely the satiator.

Balancing I can do on my old 8s RC chargers. But I find it easier to just use a light bulb to bring down a high cell here and there, and then put it back on the bulk charger. Or you can discharge higher cells using one of those battery balancer things.

 

[MadRhino]

When you parallel balance leads, you can't monitor every single cell anymore. IMO, that is a basic safety procedure with RC lipo, to monitor every cell.

To make your 12s 3p, I prefer to parallel 3 series of 2 bricks, and leave the individual balance leads functional. Bulk charge in 15 minutes with big 48v PSU, monitoring every cell while charging. RC lipo doesn't need to be balanced every time, in fact you could use them for a whole season without any balancing if you never discharge below 3.7v

 

[dogman dan]

If one cell does get weak, I want it to die all by itself, not taking another pack with it. It can be a lot of jst's to check, one of the reasons my packs never exceed 10 ah each. For a long ride, I just carry multiple 48v 10 ah packs.

I can check every cell in a 10 ah pack, in about one minute. Bulk charging to less than 4.2v, gives me some wiggle room to avoid an overcharge.

 

[docnjoj]

For us slow guys 12S is series and each cell is monitored. It is true that once you parallel cells you do lose some accuracy. High quality 18650's in Sony or LG rarely fail, so I would and do parallel them. But as usual DMD and MR are right when you use hi-power batteries like they do. For the Thunder or Hyperion chargers I would keep the charge rate 5 amps or less. Mine are 2.5 year old with minimal problems. You just need to change the balance cables periodically. I always balance charge, so I always know the state of my cells. I better now that I have joined "the dark side" with LiPo.
otherDoc

 

[dnmun]

Hi guys,
Sorry for asking what has been asked probably many times but I'm all confused
My ebike has 12S 3P 5000mha pack. I paralleled all my balance leads from each 6S 3P into 1 and my 2x 6S 3P are connected in series. I use a 12S capable charger so I just need to plug my 2 main battery leads and 2 ballance leads et voilà!

The problem is that I have blown 2 chargers doing this after 1 year or less of use. It seems that these chargers are not meant to charge such big batteries even if their input voltage is above say 23-24V they really heat up.
-How the heck do you do it with a regular PSU?
-You probably absolutely need a BMS? Or could I just balance once in a while?
-Can you adjust final voltage easily? I like to charge at 4.16V but when going on long rides I will take them up to 4.2V

Thank,

did you start a thread about your balancing chargers? without knowledge about how it failed it is impossible to answer your question.

to use a bulk charger for 12S then you need a charger that has an output voltage of 50.4V and most of the lipo BMSs can be hacked down to 12S with no problem.

if you wanna fix the chargers then start a new thread on them and post up pictures so we can see how it is built to inform you of how to test it.

 

[rborger73]

I'll say the Thunder 1220 has done well for me. It gets carried in my backpack and has charged my 12s 20Ah, then 30Ah, then 40Ah, and now 50Ah pack wonderfully for the most part over the near 9,000 miles and a little over a year of service now. I push it at 420 watts and push around 6.3A into the pack on average. It will likely be getting a break since I'm about to order the Adaptto mini e and should be able to lighten up my back pack a bit on my commutes now. I'll have the Thunder as a backup bulk charger, just only for long trips for more than a day. I only have to balance, and just barely, once every few months since I don't run my pack down anywhere near the low side of a charge. And most variance I see is usually .05 or less. More like .03 after a month or so of bulk charging. I check cell balance once a week or so. But the Thunder does very well as a bulk charger.

 

[wesnewell]

What charger are you talking about? What PSU are you using to power it and at what voltage/amperage? I've been using a Hyperion 1420i and a 600w 24V psu for over 4 years without a problem. The last 3 years charging 20ah of 12s4p.

 

[rborger73]

Not sure if you meant me or the OP, but I run a Thunder T350 350watt 23Amp Power Supply. First one I got was doa, second one seems to be holding. Never did return the first one due to not hearing back from customer service for months and just forgot about it. Figured I'd have some spare parts if something burns up on this one. There are certainly better Psu's out there. This particular one has served me well thus far.

 

[motomech]

Any cheap 350 Watt server supply will power the Thunder 1220.
About $20 on Ebay or I think icecube57 has them in the Sale section.
The Thunder will get darn close to 300 Watt, not the fastest, but a very sturdy charger. Going on 3 years with mine.
I didn't think much of the supplied stiff balance cables and crappy adapto board. They could be upgraded, but I had some Battery Medics, so I just use those.
Highly recommended.

 

[RC_guy]

Well I had the Thunder 1220 and it blew after 1 year of charging at max 6 amps.
THen I got a Hyperion EOS1420i and that blew after less than 1 year. these chargers do not like max output for prolonged periods of time.
Now I have a Thunder Power 1430C and it really sucks that it is rated to 1000W or 30 amps. But to my surprise, when I could not charge above 10amps for a 12S pack, I noticed a chart on the last few pages of the manual that state the power output VS output voltage (# of cell in series). For an 8S, the charger is rated at 1000W, then a 10S 700W, and a 12S 500W

In both failures, my chargers were shutting down my computer PSUs. I thought it coule be the PSU that was faulty so I hooked them up to a car battery and nothing happened.
I still have both but there is no apparent damage.

Is there a chance they could be repaired relatively easily?

 

[ddk]

first-hand experience with the 1220:
if your PSU is underrated the thunder WILL let you know. It also stops the charge cycle.
It allows you... in fact you HAVE to set its' input power before the charger will start its' cycle. If the PSU can't provide the power, the 1220 sets off an alarm.
If your 'car battery' is low the 1220 gives notice warning.

Needless to say, mine has been trouble-free also.

 

[rborger73]

How many miles did you put on in the year you had the 1220 that died after a year? I'll be hitting 9,000 miles at the end of the month or so, which is a ton of charging cycles all done at 6a. On top of which I normally carry the 1220 in my backpack unless I'm just making a quick run. I can't complain about it at all. I won't miss it in my backpack once I get the adaptto though.

 

[dnmun]

Well I had the Thunder 1220 and it blew after 1 year of charging at max 6 amps.
THen I got a Hyperion EOS1420i and that blew after less than 1 year. these chargers do not like max output for prolonged periods of time.
Now I have a Thunder Power 1430C and it really sucks that it is rated to 1000W or 30 amps. But to my surprise, when I could not charge above 10amps for a 12S pack, I noticed a chart on the last few pages of the manual that state the power output VS output voltage (# of cell in series). For an 8S, the charger is rated at 1000W, then a 10S 700W, and a 12S 500W

In both failures, my chargers were shutting down my computer PSUs. I thought it coule be the PSU that was faulty so I hooked them up to a car battery and nothing happened.
I still have both but there is no apparent damage.

Is there a chance they could be repaired relatively easily?

how can we answer if we do not have any idea of what is broken? if you wanna repair the chargers then open them up and show pictures of the insides. we can direct you where to test. if you have no DVM or any experience repairing things as seems to be the case then it will seem more difficult than it usually is.