found new cheap site for BMS, LiFePO4 & charger up to 18000W

Doctorbass

Doctorbass

100 GW
Joined
Apr 8, 2007
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Location
Quebec, Canada East
Yes, the prices seem too good to be true. :) I agree, that charger is pretty cool, for only $78. You still have to get it over to our side of the pond, however.

The BMS page shows a board that looks identical to the ones BatterySpace is selling here, but when you go to the next level down for any of them, they have two totally different looking models. The cheaper ones, with the "bleeding resistor" balancing mode, look a lot like BatterySpace's 20A models. The other BMSBattery model, apparently uses an "energy transfer" type of balancing system, maybe like the switched capacitor concept. I think the 15A limit is a typo. These have to be capable of higher discharge rates.

BatterySpace seems to have three different sources for their 20A, 40A and 60A BMS boards. They all look completely different, but all are priced the same. All of these use resistive shunts for balancing, but they shunt current is pretty wimpy, at 35mA, 75mA and 170mA, respectively.

-- Gary
 
My guess for that "energy transfer" balancing is that they're using Texas Instrument's bq78PL114 "PowerPump" BMS chip. Micro-Power also uses it (and TI's gas gauges) and it's appearing in more and more products.
 
Found another site saling the exact same products.. BUT WITH LARGER PICTURES..

and please note that the BMS that BMSBATTERY website have are not limitated to 15A like they show.. they did a simple copy paste error.. this new supplyer proove that..but this one have no price.. so with both site we have all hgood info :wink:

http://www.ecitypower.com/index.php?page=70

Doc
 
Some corrections.. these BMS are finally not all limited to 15A.. they have up to 100-150A

here is the list price of eCityPower the second compagny i received:
 

Attachments

  • eCityPower List Price 2009.xls
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Cool... I'm building 10s, 12s and 14s konion packs and have been looking for a single charger solution for all 3 packs. Maybe I'll play guinea pig and order one of those. I can't imagine shipping will be cheap to US though. :?

Forgive my ignorance, but if I got the very cheap 200w 10-75v how long would that take to charge a 58.8v15ah pack? Like around 4-5hrs? Also.. how would you adjust the charger do you think? Can it be done on the fly or would you have to go in and adjust pots internally? I can't tell, but assume it's an internal thing.
 
I love their slogan.

Edited to say: Seems like everybody's getting good stuff for great prices, so I'll take back what I said earlier.
 
pwbset said:
Cool... I'm building 10s, 12s and 14s konion packs and have been looking for a single charger solution for all 3 packs. Maybe I'll play guinea pig and order one of those. I can't imagine shipping will be cheap to US though. :?

Forgive my ignorance, but if I got the very cheap 200w 10-75v how long would that take to charge a 58.8v15ah pack? Like around 4-5hrs? Also.. how would you adjust the charger do you think? Can it be done on the fly or would you have to go in and adjust pots internally? I can't tell, but assume it's an internal thing.
Click to expand...


yu have 58.8V 15Ah to charge and 200W chager.

some maths: 58.8 x 15 =882Wh

Time = energy/power = 882/200=4.5h


I know that some charger have potentiometer adjustement..

Doc
 
just started liking their 48 V LiFePo when I realized they weigh in at 9500 lb. It's probably ligther to install an elevated lake in your trailer and feed a water turbine generating electricity as you go ...
 
europa81 said:
just started liking their 48 V LiFePo when I realized they weigh in at 9500 lb. It's probably ligther to install an elevated lake in your trailer and feed a water turbine generating electricity as you go ...
Click to expand...


:lol:

this is typical from chinese website... they made an error ... factor 1000 !!!

it should probably weight 9.5lbs.. that make more sens!

Doc
 
I have emailed about shipping, but have not heard back from them. Sure wish there was a CA/UK/US dealer for these chargers.
 
When I inquired about these products, I got a pricelist in reply from a guy by the name of Jack, but then I got another email from Mandy Li who seems to be pretty technically literate about the products - she included some more detailed tech info. So I straight up asked where the cells are coming from- whether they're making them themselves, or what manufacturer they're buying them from. Having read a little about some of the fly-by-night Chinese batt companies, I'm interested to see what kind of response I get back - I'll keep you guys posted.
 
Yeah I got quoted $25 to ship the 200W charger to the US. Responsive email and polite and good English. I'm likely going to order a couple of their cheaper chargers next Friday when I get paid. I'll report.
 
So I asked about the voltage adjustability on the chargers and got this back...

The charger EP-J is not adjustable.
Only one model EP-B can be adjustable.Outside dial.
Click to expand...

Can someone educate me how a 10-75v charger is not adjustable? Does it just know if I have a 16s LiMn string for example? Figured I'd have to set that to 67.2v by hand somehow.
 
pwbset said:
So I asked about the voltage adjustability on the chargers and got this back...

The charger EP-J is not adjustable.
Only one model EP-B can be adjustable.Outside dial.
Click to expand...

Can someone educate me how a 10-75v charger is not adjustable? Does it just know if I have a 16s LiMn string for example? Figured I'd have to set that to 67.2v by hand somehow.
Click to expand...

I think they mean that their charger are adjustable inside (probably a pot or resistor network to set) and thay they have some model with outside adj... like they responded :wink:

Doc
 
OK so I got some more data on this company. Attached you'll find 2 spec docs that were sent to me, which inspire some confidence. Mandy Li also stated that they are a manufacturer w/a factory, and not a reseller. However, the address listed on the PDFs attached is that of an office building (there are numerous other firms listed w/thier addresses there, and most addresses include a "Tower" number - obviously not a manufacturing plant). I understand that the factory and the sales office may not be in the same location, but that seemed a little fishy to me.

Thoughts?
 

Attachments

  • EP8081230.pdf
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  • EP7570260.pdf
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9.5 pounds for 20aH@48V? 9.5kg perhaps? Weight becomes pretty unreliable when you have moved the decimal point and changed the units of measure. If it is really 9.5 pounds, I'm buying five of them. Ahhhh, 50 pounds and 100aH, I can dream, can't I?
 
I looked at the spec sheet. 280g per cell at 10aH. That makes it 9.8 pounds for a 48V 10aH system without packaging, bms, interconnects, wire, etc....
 
mrgarci1 said:
OK so I got some more data on this company. Attached you'll find 2 spec docs that were sent to me, which inspire some confidence. Mandy Li also stated that they are a manufacturer w/a factory, and not a reseller. However, the address listed on the PDFs attached is that of an office building (there are numerous other firms listed w/thier addresses there, and most addresses include a "Tower" number - obviously not a manufacturing plant). I understand that the factory and the sales office may not be in the same location, but that seemed a little fishy to me.

Thoughts?
Click to expand...

Google Earth is your friend. you can look up almost any address on earth and see the building from space. if they have recent pic'ies you might even be able to zoom in real close. sometimes you can use this to see if their plant is actually a building or just a dining room table pressed into service.

rick
 
mrgarci1 said:
OK so I got some more data on this company. Attached you'll find 2 spec docs that were sent to me, which inspire some confidence. Mandy Li also stated that they are a manufacturer w/a factory, and not a reseller. However, the address listed on the PDFs attached is that of an office building (there are numerous other firms listed w/thier addresses there, and most addresses include a "Tower" number - obviously not a manufacturing plant). I understand that the factory and the sales office may not be in the same location, but that seemed a little fishy to me.

Thoughts?
Click to expand...

I'm not going to get into badmouthing a company much, but I met these people when I was in China, and I can say that I have lost money to them. Their claims to have a factory are questionable (a former employee of theirs gave me some information that called this into question).

Their current products may be fine... but watch out if you need warranty support.
 
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