BMSBATTERY Customer Experience LiFeP04

Shouldn't a 16s pack charge to 58.4? 55 sounds a bit low, like by 3.4V, don't have a dead cell in there do you?

Gow.
 
Uhm, to the guy here who was asking about pulling parralel out of a 48v pack. That would entail shorting the pack, I believe [it's bad]. you can't put the same thing in parallel that you set up in series.
 
auraslip said:
You're thinking of lipo maybe?

Almost fully charged at 3.4v

16 X 3.65 = 58.4 The charger should be set to charge a string of 16 LiFePO4 cells to 3.65V per cell for 58.4V total. his charger is only charging to 55V which is 3.4V short of a fully charged 16s pack. At 55V his 16 cells are only being charged to 3.43V
 
I know. He should fix it if he can. OTOH, I've been charging a 16s lifepo4 pack with an SLA charger for the past month that only puts out 55v. Charging to 3.4v isn't a big deal. You hardly lose capacity/range, and it's very beneficial for cycle life.
 
My charger is outputting 58.6V at no load. I can read this voltage at the battery discharge lead once the BMS cuts out. As soon as the battery turns on again, the voltage drops to 54-55V which seems to be the actual charging voltage.
 
I had this happen on a 72V headway pack, the charging voltage dropped from 87.6V to 87.1V. There were two cells that just won't hold beyond 3.3V even charging them individually with an RC charger they reach 3.6V, then within minutes they drop to 3.31 ish.

I'm replacing the cells.
 
Regrarding pulling 12 volts parallel out of a 48v pack to run a 12v to 110 inverter. Ok, thanks to the guy for the comment about shorting the pack, I thought about it some more. In order to do it I think I need to make 4 separate 12 volt packs out of it and parallel the outputs to get the 12 volts out that would balance the pack and give 4 times the 48v AH rating. When I want to use or charge it as a 48volt pack for the bike I need to plug in a connector that will series the 4 packs together.

I just talked to our in house power expert and he had a better idea! Just take the 48v DC to a 48V DC to 100V ac inverter. The telecom market does this all the time since they work off 48VDC inputs. That will save a lot of effort and V loss by eliminating the extra wires/connectors. :) Going to google 48vdc to 100vac now.
 
BMSBattery Order (3-24-11):
48V 1KW Q12 Rear e-bike kit
48V 20AH 38120 LiFePO4 with BMS upgrade - Discharge 200A (or so they say)
1200W Alloy Shell LiFePO4 charger
Misc parts
Total: ~$1,200

I received some of the shipment about a month later (4-20-11): The 48V 1KW Q12 Rear e-bike motor/kit was not included in the shipment. Lots of wires that seem to go nowhere and no instructions – hey – I’m a real man, I don’t need no stinking specifications or instructions – right? I don’t even need a motor: I’ll just connect the battery leads to my important parts and push.

I immediately informed my BMSBattery customer service representative, Judy Liu, regarding the missing items. For some cryptic reason, she wanted me to send an additional $30 for this order. I sent the extra money several weeks ago, I still have not received anything, except her responses; there is only ever one part of her responses that is on point and/or intelligible: she says, "so sorry".

This makes absolutely no sense to me; this isn't a language translation problem or a cultural misunderstanding, I'm not being unreasonable, impatient, or disrespectful in any way. I guess that I'm just one of those silly Americans who think that invoices represent a legal contract. I guess customers in China pay their invoices with no expectation for delivery of the product they ordered. I guess that customers in China are happy to be held hostage for additional charges with no expectation of a result. Just pay - that's all --- "so sorry" is good enough for them.

Here in The United States of America, the invoice details the product to be delivered and the payment required.
I paid the invoice; I even paid the requested additional charges.... and now (silly me) I expect to receive the product; the invoice is a legally binding contract between the vendor and the customer (how do you say that in Cantonese)
Today is (5-11-11) It’s going on two months, e-mail communication has done absolutely nothing for my situation; I still don’t have the product I ordered. This can't possibly be a 'not-in-stock' issue. The more you complain, the less likely they are to understand or even respond.
:cry: :cry: If anyone wants to hear the details of this failed transaction, ask and you shall receive my so,so sad “American”response. :cry: :cry:
 
Acmesportman,

Oh man.... Your sarcasim makes a tragic comedy. If you don't want to cry then its better to just laugh. Sorry.... The only way to light a fire under thier arse is to submit a paypal dispute. That gets thier attention and I got my stuff within a few days after that. Another gentlemen got his money back after filing a dispute. I feel your pain dude. Nothing worse than a grown man waiting on a great toy that is going to be a lot of fun and they don't deliver on what they promise. Sucks big time. Hang in there and hopefully they will make it right. I know what you mean about emailing Judy and Jack. They just ask dumb questions over and over and its very frustrating to say the least.

Good luck,

Dal
 
Dal,
I paid the BMSBattery invoice with my AMEX Card via PayPal, but I wasn't logged into PayPal as a member, I was a guest. I had to file my complaint with AMEX; they apparently worked with PayPal to file a PayPal dispute. The PayPal dispute apparently motivated BMS Battery to fulfill their order responsibilities. After more than three months, and more than 60 email communciations; BMS Battery has finally shipped all the product that was listed on my original invoice.

It took more than 20 emails and five months to get PayPal to "allow" me to close my PayPal account and I'm not going back. After more than six years as a PayPal member, they required that I 'verify' my account. They required me to give them my on-line banking account log-on credentials; I refused. I pointed out that this would give them the authority to withdraw funds without my knowledge or permission and that this was a security risk. Apparently, the average Joe these days is willing to give PayPal whatever information they might want.

BMS Battery said:
Hi,

Thank you very much! We will improve our service in the future. We will promise to deliver during one week when we finished updating production facility. Thank you for your good advice.

Best regards,
Jack Xie

If I had a better vendor for LiFEPO4 batteries, I'd use it, but I don't at this time.
 
they've been very quick making my custom chagers lately, my orders usually arrive within 1-2, max. 3 weeks from payment day. the shipping rate is not so bad for a 2-6 workday service, is it. combine more items for much more reasonable cost per item. if you buy a bpm motor, insist on the correct CODE before you place an order even if you know the correct voltage / RPM combo. rear motors are usually sensored, unlike the fronts.
 
http://endless-sphere.com/forums/viewtopic.php?f=14&t=38284

various. most flawless, some fishy.
i recommend you buy a spare 240W or 400W unit along with a big one.
 
Gow864 said:
I had this happen on a 72V headway pack, the charging voltage dropped from 87.6V to 87.1V. There were two cells that just won't hold beyond 3.3V even charging them individually with an RC charger they reach 3.6V, then within minutes they drop to 3.31 ish.

I'm replacing the cells.


i just read this. for the headway to drop from 3.65 to 3.3V is pretty normal. it usually is about 3.42V it seems but just the initial drain off of the top of the charge doesn't mean the cell is dead, imo.

that's the way the headways seem to rest. some rest fast others just a little slower but they all drop to about 3.42V and stay at that point for a long time after that.
 
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