Battery Blues...need advice

[Leebolectric]

[youtube]V0KO0TDiQz8[/youtube]
My battery dilemma...
I have two of these batteries...both 52v20ah Samsung 29e.
I also have two matching chargers for them.

Both batteries in question were purchased about 30-45 days ago...and were first charged 2 weeks ago.
One acts fine and charges as planned....but the other is being trouble, I think.
Both have been charged around 10 times at 3 amp rate, but when charged to "full", one charges to 58.6v and one of them only receives 54v.
The charger SAYS the bad one receives full 58v charge, but when unplugged the bad one drops back down to 54v...odd...
The good battery, purchased and charged at the same times as the bad one, and used on a bigger motor works perfect...AND it still charges to 58v.
Both chargers do the same thing and still work proper on the good battery, so I doubt it's the charger...

Why is this happening to my "new" battery? What am I missing?

Many Thankies
(and HappyNewYear!)

 

[Leebolectric]

Both batteries haul ass and make me smile...so power is definitely flowing good.
I just worry about those voltages...

 

[Jon NCal]

Best to work it out with your vendor ASAP so repair can be under warranty.

 

[Leebolectric]

so, you think this is a repair issue? or warranty?
I wanted to make sure here before expensive shipping costs and stuff.
I also wanted to make sure I wasn't missing something myself...cuz I'm new to this.

 

[Jon NCal]

so, you think this is a repair issue? or warranty?
I wanted to make sure here before expensive shipping costs and stuff.
I also wanted to make sure I wasn't missing something myself...cuz I'm new to this.

yes, 4V low is a big deal. Your vendor can best advise you what to do next, and help you troubleshoot.

 

[Leebolectric]

excellent, will do.
they have been very helpful in the past with issues, so should be easy.
I would just hate to hassle them if it was my fault, ya know ...thanks for the tip.

 

[nutnspecial]

Maybe a single cell, cell connection, or the bms is causing it. Well written op, ruling out the charger in operation and readout.

Be cautious with the pack until full diagnose- likely a seller issue unless you opt to dissect the thing.

Maybe seller will just refund and you can fix via forum help. (not mine tho , don't kno a thing about this issue or this type of pack and bms)

 

[2old]

Your build reflects 25r cells; did you change? Considering Dave's unit and interested in which battery to use.

 

[dogman dan]

Drops exactly 4v when removed from the charger sounds exactly like one group of cells is not holding any charge at all.

You need to contact that vendor, and start a warranty process on that pack.

 

[Leebolectric]

2old...I have another pack, 52v20ah 25R for the Tangent kit...and I also bought these two 29e packs for our commuters, and have tried them with the Tangent.
Either battery feels fine...but the weather hasn't let me take it out for real yet. From what I've seen the 25r is the best for his kit, 30q is interesting too, needs more info.

Thanks all, warranty talks beginning, really appreciate the advice.