Battery Charger, plug in 1st, or plug in last?

[imorton]

Good day Everyone, I have ordered a 48v LifePo4 pouch battery (similar to Ping) and it comes with a 5amp battery charger. I haven't rec'd the battery/charger yet, but it appears identical to this one (photo's of the insides) http://endless-sphere.com/forums/viewtopic.php?f=14&t=59549

When it comes to using the charger, do I plug it in to the AC Outlet first, or plug it into the Battery first?





I have had other chargers (ex: 24v SLA) that recommended plugging it to the battery first, than plug it into the 120v AC outlet. My current 48v SLA charger recommends to plug it first into the wall outlet, than into the battery. I am totally confused, and don't want to fry the battery charger needlessly.

So, what manufacturer instructions have you read, or what method do you use to maximize or not fry these cheap but necessary chargers?

#1) Do I plug the battery charger to the 120v AC wall outlet FIRST, than connect the charger to the LifePo4 battery?

#2) Or do I connect the battery charger to the LifePo4 battery FIRST, than connect the charger to the 120v AC wall outlet?

I really appreciate your feedback, and am curious how you do it… (in order to not fry one)

IAN.

 

[whereswally606]

personally I do #1 first ie wall then battery. simply because in my case I get a spark from the connector if I do it battery then wall as the caps in the charger are empty and thus the charger is leaping from 0 to 52v whereas if the charger is on then no leap. 52 to 52v

 

[izeman]

wall outlet first, then battery. always.

 

[DAND214]

wall outlet first, then battery. always.

Like he said.

Dan

 

[imorton]

It looks (so far) that #1 is the way to do it…

I am sure others will also reply, and if someone has proof from a manufacturer or fried chargers from doing it via #2

IAN…

 

[r3volved]

I connect wall first, battery second and disconnect battery first, wall second.

I get a small spark from connecting to the wall, but chargers are cheap (comparatively) and I'd rather blow a charger than my battery

 

[imorton]

I connect wall first, battery second and disconnect battery first, wall second.

I get a small spark from connecting to the wall, but chargers are cheap (comparatively) and I'd rather blow a charger than my battery

I don't think you would blow the battery, I think you're mostly likely to fry the charger.

It's something about by plugging into the wall first it charges the capacitors, by charging the capacitors it reduces the spark.

Ian

 

[imorton]

Does any know what causes these "cheap chargers" to blow/fry from improper plugging sequence?

IAN.

 

[izeman]

as already mentioned, imho plugging it into the wall outlet charges the charger's caps first and adds voltage to the charger's output.
if you connect the battery first, the battery will instantly charge the charger's caps and this will cause a spark (depending on cap's size and voltage of course).
there may a spark even if you do it the other way round, but this is because of the voltage difference between the charger's output and an empty battery. if you connect a (almost) fully charged battery to a charger there will be no spark.

 

[imorton]

So the plugging sequence can affect the "spark".

But what generally causes the many complaints of these charger failing. Is it related to plugging to the wall first, or to plugging it to the battery first?

IAN.

 

[izeman]

But what generally causes the many complaints of these charger failing. Is it related to plugging to the wall first, or to plugging it to the battery first?

IAN.

i don't have any experience with this special type of charger (the are way too slow for me), but i suspect it's cheap components installed by poorly trained staff and no QC afterwards.

 

[cal3thousand]

I always plug to the wall first and fill the caps that way.

I've heard it said another way by LFP: You want to always power up the CV stage before plugging in the battery.

 

[melodious]

: I had the wall plug charger battery when an oncoming storm blew power for a few minutes. Power came back on in the home, but my charger was showing a green LED. Curious, I unplugged the charger from the battery and reconnect to battery (FYI, I power the charger before connecting to battery), in which it started going into charge mode.