Search found 22 matches

by pratikdas87
Oct 01 2018 8:18am
Forum: E-Bike General Discussion
Topic: I-charger 308 duo
Replies: 1
Views: 191

I-charger 308 duo

Hey group members, My i-charger 308 duo stopped functioning. while discharging it is saying discharging is done with in a minute not reaching the desired current value.during charging it is showing error 1301( connection error), while all my connections seems OK. I have checked the PCB by opening th...
by pratikdas87
Aug 03 2018 11:29pm
Forum: Battery Technology
Topic: Homemade Battery Packs
Replies: 1627
Views: 435158

Re: Homemade Battery Packs

3.6V vs 3.7V rated cells are rated as the average discharge voltage over the entire discharge cycle at a specified discharge rate. Factored are Internal Resistance (IR) and rated DOD Not as the discharged "empty" voltage, more a coincidence than a "rule", with older LiCo cells. Previously, not so i...
by pratikdas87
Jul 31 2018 10:21am
Forum: Battery Technology
Topic: Homemade Battery Packs
Replies: 1627
Views: 435158

Re: 2015 - Cell Testing Methodology

Stage 3 Comparative IR Test cell pairs for a comparative internal resistance. While monitoring cell voltage, apply modest drain (2A?) and note voltage sag. Remove any with notably greater voltage sag. These are likely very poor capacity cells or one of pair is bad. Separate and test for alternate u...
by pratikdas87
Jul 31 2018 8:18am
Forum: Battery Technology
Topic: Homemade Battery Packs
Replies: 1627
Views: 435158

Re: Homemade Battery Packs

I've got some new salvaged 18650 batteries from laptop packs the read 3.7v, 24 of them, the packs say they were 14.4 volts but that doesn't add up. 8X3.7=29.6. Huh? Also I have 18 from a 3M projector that rated the battery pack at 10.85 or 11.1v. They read 3.6v. That math pans out. Please explain. ...
by pratikdas87
Jul 31 2018 7:48am
Forum: Battery Technology
Topic: Homemade Battery Packs
Replies: 1627
Views: 435158

Re: Homemade Battery Packs

stealthhack, buddy be careful with what you are doing. I see you have 3.6V mixed with 3.7V cells. So the max voltage should not go higher than 4.05V and lowest 3.75V otherwise you will be looking for trouble with old cells! Did you do a sag test on each bank while putting a 1C load on the whole pac...
by pratikdas87
Nov 08 2017 1:01am
Forum: E-Vehicles General Discussion
Topic: E-bike safety
Replies: 6
Views: 1092

Re: E-bike safety

Drunkskunk wrote:There have been several members of this forum who have lost their bikes, sheds, garages, and even homes to battery fires. we have collectively learned our lessons the hard way. What Alan B posted should be taken as an absolute set of ebike battery rules.
Thank you
by pratikdas87
Nov 07 2017 1:04am
Forum: Battery Technology
Topic: LIfe time prediction of pack made with second life cells
Replies: 0
Views: 206

LIfe time prediction of pack made with second life cells

Dear Fellow forum members, I am making battery packs with second life lithium ion cells. As, many people in the forum has already made packs from laptop cells and tested the lifetime, I would like to get some advice on how to predict it. If there are any important parameters to consider, please let ...
by pratikdas87
Jun 15 2017 1:50am
Forum: Battery Technology
Topic: help needed_ Specific safety aspects in battery pack
Replies: 3
Views: 390

help needed_ Specific safety aspects in battery pack

hey guys, i recently joined the group. I am making my own battery pack. i have some specific questions regarding safety aspects. 1. are there any precautions/guidelines with respect to designing 18650 packs such as certain materials to avoid etc. particularly from safety point of view. 2. If there a...
by pratikdas87
May 21 2017 11:20pm
Forum: Battery Technology
Topic: BMS_Testing
Replies: 0
Views: 209

BMS_Testing

Dear All, I am making my own BMS using chip and microcontroller from TI. DO you have any suggestion what kind of test i should do after i make my BMS to ensure that, it will work in the final battery pack? Is there any specific tests i need to do or any important things i need to check once the BMS ...
by pratikdas87
May 17 2017 6:16am
Forum: Battery Technology
Topic: Battery pack_high temperature safety issue
Replies: 7
Views: 602

Re: Battery pack_high temperature safety issue

http://i68.tinypic.com/2gsn7dx.jpg well 48v 100ah isn't a small cheap pack that you could afford to replace every couple of years. perhaps you should think about active cooling the cells would certainly "work" at elevated temperatures but the calendar life might not be satisfactory i'm not too sure...
by pratikdas87
May 17 2017 6:14am
Forum: Battery Technology
Topic: Battery pack_high temperature safety issue
Replies: 7
Views: 602

Re: Battery pack_high temperature safety issue

Like AW,, I live in the western desert, where a 110F/43c day is common. Worst I ever saw here, where its a bit cooler than Phoenix, was 118f. We still have EV's and don't cook our batteries in one season. As long as the vehicle is moving, temps like these should not be a problem at all for your cel...
by pratikdas87
May 17 2017 6:10am
Forum: Battery Technology
Topic: Battery pack_high temperature safety issue
Replies: 7
Views: 602

Re: Battery pack_high temperature safety issue

What are the manufacturer's temperature ratings for the cells? What does the manufacturer say will happen if they are exceeded? You'll need to know things like that to determine pack limitations. If the cell specs are greater than the temperatures they'll actually experience, I don't see what the p...
by pratikdas87
May 16 2017 2:26am
Forum: Battery Technology
Topic: Battery pack_high temperature safety issue
Replies: 7
Views: 602

Battery pack_high temperature safety issue

Dear All, I am designing a 48V 100Ah lithium ion battery pack (NMC chemistry) for mobility application. The battery pack will be used in a hot weather conditions. Average temperature in summer greater than 43 °C. I need some advice regarding the safety issues. My BMS has a high temperature protectio...
by pratikdas87
May 16 2017 1:57am
Forum: General Discussion
Topic: Battery pack making_Help needed
Replies: 4
Views: 543

Re: Battery pack making_Help needed

spinningmagnets wrote:Go to the battery section, and look for the stickie thread index

edit....click here:
https://endless-sphere.com/forums/viewt ... 3#p1051327
Thank you :D
by pratikdas87
May 12 2017 7:56am
Forum: General Discussion
Topic: Battery pack making_Help needed
Replies: 4
Views: 543

Re: Battery pack making_Help needed

Actually most of the time people suggest paralleling first, then seriesing, because of the way BMS's are designed (they monitor a series of parallel groups). So the way you describe doing it is the normal way it is done. As long as there is sufficient current path from one group to the next, it wor...
by pratikdas87
May 08 2017 11:34pm
Forum: General Discussion
Topic: Battery pack making_Help needed
Replies: 4
Views: 543

Battery pack making_Help needed

Dear All, I am making a battery pack for myself using 18650 cells. I want to make a 3S5P system. my question is can i make 3 blocks of cells each having 5 cells in parallel, and then connect them in series? normally, people advice to put sells in series first then to connect parallel cells. in my ca...
by pratikdas87
May 08 2017 11:27pm
Forum: General Discussion
Topic: IMax B6_ balancing during operation
Replies: 14
Views: 1174

Re: IMax B6_ balancing during operation

A quicker way to balance with the b6 or similar chargers, is to do a quicker non balancing charge, then select any cell that is particularly low, and charge it as a single cell. To do that, you need to make an adapter, so you can charge one cell through the balance plug. one end of the adapter fits...
by pratikdas87
May 05 2017 4:59am
Forum: General Discussion
Topic: IMax B6_ balancing during operation
Replies: 14
Views: 1174

Re: IMax B6_ balancing during operation

A quicker way to balance with the b6 or similar chargers, is to do a quicker non balancing charge, then select any cell that is particularly low, and charge it as a single cell. To do that, you need to make an adapter, so you can charge one cell through the balance plug. one end of the adapter fits...
by pratikdas87
May 04 2017 12:57am
Forum: General Discussion
Topic: IMax B6_ balancing during operation
Replies: 14
Views: 1174

Re: IMax B6_ balancing during operation

markz wrote:I have the iMax b8+ and I have watched what Dan just described.
It takes a long time to finish.

It would have been best to step up to a 10S iCharger, but then why not just buy a Satiator.

Live & Learn
Hey Markz,
you are right about Dan. I also observed the same.
Thank you.
by pratikdas87
May 04 2017 12:55am
Forum: General Discussion
Topic: IMax B6_ balancing during operation
Replies: 14
Views: 1174

Re: IMax B6_ balancing during operation

Top balancing. You can watch it happen on your display. One cell gets high, charging stops. you will see that cell discharging, then charging re starts. The resistor will connect, and the high cell gets discharged. At a certain point, the circuit opens, and the resistor is not connected anymore. Wh...
by pratikdas87
May 04 2017 12:54am
Forum: General Discussion
Topic: IMax B6_ balancing during operation
Replies: 14
Views: 1174

Re: IMax B6_ balancing during operation

kingjamez wrote:It's resistor based balancing, it discharges cells to balance them.

-Jim
Thank you JIm. really appriciated.
by pratikdas87
Apr 27 2017 6:19am
Forum: General Discussion
Topic: IMax B6_ balancing during operation
Replies: 14
Views: 1174

IMax B6_ balancing during operation

Dear all, I am trying to charge lithium ion batteries (NMC-graphite) with 3S1P configuration. I am using a ImaxB6 for the charging and discharging process. I would like to know if someone can tell me what kind of balancing is done by the IMaxB6. Is it a top balancing (like passive balancing) or an a...