Bulk charging A123 with a Meanwell SP-320-48

[potatorage]

Hey guys! I just got my Meanwell SP-320-48 to work but I have a few concerns with it.
First, the meanwell supply trips all the GFCI circuits that I've tried to plug it into. While this isn't a huge problem, the outlet that is most convenient for me to charge from is GFCI, and of course a lot of outdoor outlets are GFCI as well, which would be a problem if I needed to charge in an emergency.

Another problem is that the cell with the positive lead hooked up to the charger shows an abnormally high voltage (3.7~3.85) occasionally when the pack is charging. As soon as the charger is unplugged, the cell quickly goes down to normal (around 3.3V). Is this a problem?

Finally, I get a nice little shock when I touch my power supply after I unplug it. It's not lethal, but quite uncomfortable.

 

[dnmun]

something is wrong. the case is grounded.

did you open the case and modify something inside? the BMS should balance the high cells if the pack is unbalanced like that. otherwise it will be ruined if it overcharges them.

 

[potatorage]

There is no BMS. I built the pack from 16S A123 20AH Prismatic cells, and I have broken in the pack with a few cycles, balance charging each time (which takes forever). The voltage on that cell usually will fall back down to below 3.65V after a while but it stays consistently higher than all the other cells.
I only felt a tingle once, which is strange since I do see that the case is grounded.

 

[dnmun]

check continuity on the wire you are using.it sounds like the high voltage side of the front end is leaking current onto the case which should blow the fuse but does not. check continuity between the case and the ground lug on your three prong plug.

if you never opened it, it should not be doing this and could be a health hazard. as in shortened lifespan.

why would you spend good money on the A123 and not use a BMS to protect them? otherwise they could last almost forever. even an expensive BMS like the headway BMS is cheap compared to the replacement cost of these cells.

but if you use a balancing charger occasionally, that helps. except when it is left connected to the load by accident.

 

[potatorage]

check continuity on the wire you are using.it sounds like the high voltage side of the front end is leaking current onto the case which should blow the fuse but does not. check continuity between the case and the ground lug on your three prong plug.

if you never opened it, it should not be doing this and could be a health hazard. as in shortened lifespan.

why would you spend good money on the A123 and not use a BMS to protect them? otherwise they could last almost forever. even an expensive BMS like the headway BMS is cheap compared to the replacement cost of these cells.

but if you use a balancing charger occasionally, that helps. except when it is left connected to the load by accident.

I have fixed the problem with the charge on the case (and hopefully the GFCI one too). The neutral and ground wires were switched, so obviously a lot of current was leaking to ground. The main problem now is that it seems like when I bulk charge the cells are not quite balanced. One solution would be a BMS, but I would prefer something cheaper and less failure prone to help balance cells while charging.

 

[cassschr1]

I charged with the same set-up you have. I ended up with a couple puffed cells. They were overcharged.

 

[dnmun]

he wants to go the cheap route. pointless to argue against these guys. if you have a balancing charger you only then have to worry about the LVC which you can cover with cell logs and other stuff. but it all costs a lot more than a BMS.

duane's pack was so overdischarged when he got here that some of the A123 cells were popped. pack was hot as a firecracker. even now i cannot talk him into using a BMS. people think A123s are somehow safe from overdischarge. stuff happens.

 

[mihai_atanasiu]

ask ping for a BMS; it is the simplest mode to protect your cells. and you can use the Meanwell for charge with the BMS. You have to adjust the voltage of the power supply to 16 x 3.65 = 58.4 V;
If you will monitor the charging process you will see that at the end of the charging the current will be about 100 mA.

 

[dogman dan]

Yeah, that would pop a gfci plug I bet.

I can't recomend strongly enough, if you are going to bare back it, get yourself at least cheapo 50w RC charger like a b6. You'll use it to single cell charge each low cell to balance it, through the balance taps you will be putting on the pack. Two 8s pigtails and you can use a cellog 8 or pair of them to monitor the pack.

It would also allow you to split the pack later, and charge with 8s RC chargers if you want to do it better.

FWIW it takes a few low dod cycles to break in most lifepo4 packs, if you hadn't heard that yet.

 

[potatorage]

Yeah, that would pop a gfci plug I bet.

I can't recomend strongly enough, if you are going to bare back it, get yourself at least cheapo 50w RC charger like a b6. You'll use it to single cell charge each low cell to balance it, through the balance taps you will be putting on the pack. Two 8s pigtails and you can use a cellog 8 or pair of them to monitor the pack.

It would also allow you to split the pack later, and charge with 8s RC chargers if you want to do it better.

FWIW it takes a few low dod cycles to break in most lifepo4 packs, if you hadn't heard that yet.

Yes I already have a 150W 8s RC charger, and voltage monitors to go on the JST balance taps. I have heard that a break in period is necessary, but what dod should I go to? 2.8V? or lower? I haven't had the need to discharge past ~3.1V ish.

 

[dnmun]

also if you were getting any current from the case with the ground wire being used as the common during this exercise, you have a bad service ground on the house. the ground and common should be identical and you should not see any difference when you use the ground for common.

so it is more than bad wiring, you have a bad service ground on the service entrance panel or poor ground on that cable run and that could end up being a real problem if the ground wire from the power company is interrupted. if you own this place, you should examine why you have such a bad ground at the outlet. if you rent you should inform the owner.