Search found 110 matches

by DrInnovation
Oct 27 2014 3:17pm
Forum: Battery Technology
Topic: BMS sizing? SmartBMS quality? Group Buy?
Replies: 19
Views: 2170

Re: BMS sizing? SmartBMS quality? Group Buy?

Would you like the 13s with broken fets then? You can practice upon it. I think I can have it there next week for $5 I could send the 'should be' working 12s board, but it puts me in a position. Crossbreak didn't really do anything to repair it. Just tweeked the software first, then it tested ok. I...
by DrInnovation
Oct 27 2014 1:51pm
Forum: Battery Technology
Topic: Battery assembly kit for 18650 cells - first prototype
Replies: 165
Views: 39451

Re: Battery assembly kit for 18650 cells - first prototype

I did some prototypes and there does not seem to be any real need for such product. Or maybe price is too high? If this is the case, please let me know. Each new 'shape' requires new tooling and costs too much for my hobby pocket, so I am not going to do any new stuff soon. For now, I have tabs for...
by DrInnovation
Oct 27 2014 8:53am
Forum: Battery Technology
Topic: RC Lipo pack inspection, series/parallel charging, and lifespan/safety tips
Replies: 172
Views: 98293

Re: RC Lipo series charging tutorial

How can you figure out how long it will take to charge your batteries completely? Lipo batteries. Best way I know how is to measure it.. Balance charging takes a variable amount of time depending on how unbalanced the cells get and the chargers output. Even for bulk charging without rebalance, the ...
by DrInnovation
Oct 26 2014 10:58pm
Forum: Battery Technology
Topic: BMS sizing? SmartBMS quality? Group Buy?
Replies: 19
Views: 2170

Re: BMS sizing? SmartBMS quality? Group Buy?

I do like the core design of the Oz890-based systems.. With OZ890 smartBMS, I can actually watch the voltage easily (I'll build a bluetooth interface ala http://www.pedelecforum.de/forum/index.php?threads/diy-smartbms-reader-mit-atmega.22585/ and then can check it while charging every day). Plus if ...
by DrInnovation
Oct 26 2014 9:17am
Forum: E-Vehicles General Discussion
Topic: Anyone here have a Volt?
Replies: 94
Views: 13428

Re: Anyone here have a Volt?

Also my sidewall blowout on them was a issue that many have had.. they blowout pretty easy. agreed the tires are not the best in terms of wear... I've 30K miles (rated 60K I think) and well past half tread on one pair.. You might want to pump them up a bit.. the 2011's were saying 35psi but I run at...
by DrInnovation
Oct 26 2014 9:13am
Forum: Battery Technology
Topic: Battery assembly kit for 18650 cells - first prototype
Replies: 165
Views: 39451

Re: Battery assembly kit for 18650 cells - first prototype

Nice idea/kit but I'd need a different size than on the "sale" thread.. So I figured I'd post 2 questions/suggestions. here Have you considered (or would you consider) designing the fused elements as basically a long strip.. for welding 18650 many people already buy nickle strips.. if they could buy...
by DrInnovation
Oct 25 2014 7:27pm
Forum: E-Vehicles General Discussion
Topic: Anyone here have a Volt?
Replies: 94
Views: 13428

Re: Anyone here have a Volt?

Any issues with faulty brakes ?? A couple (of the few) Volt owners in Australia have reported total, permanent, brake failure ! GM (Holden dealers here) have apparently been unable to find a cause or rectify the problem and replacement cars have been supplied instead. Anything similar reported inth...
by DrInnovation
Oct 25 2014 7:20pm
Forum: E-Vehicles General Discussion
Topic: Anyone here have a Volt?
Replies: 94
Views: 13428

Re: Anyone here have a Volt?

@ DrInnovation & Doctorbass, Just curious how the Volt drives in the snow? I have noticed the front end clearance is very low and am wondering how well it drives in anything over a few inches. Do either of you install winter tires on your car? Ed Drives well in the snow.. its so heavy it sticks wel...
by DrInnovation
Oct 25 2014 7:15pm
Forum: Battery Technology
Topic: BMS sizing? SmartBMS quality? Group Buy?
Replies: 19
Views: 2170

Re: BMS sizing? SmartBMS quality? Group Buy?

Oh yes, crossfire was an 80s tabletop game. I still have it in fact :) I like the smart bms. I must of had half dozen of them. Programmed by suppliers. I have heard the concerns of others, but they just seemed like user error. Setting the charger and hvc to the same voltage being quite a common one...
by DrInnovation
Oct 25 2014 8:59am
Forum: Battery Technology
Topic: BMS sizing? SmartBMS quality? Group Buy?
Replies: 19
Views: 2170

Re: BMS sizing?

Well looked at the smart BMS from bmsbattery.. interesting but the quality of ecitypower seems questionable (many problems). (http://endless-sphere.com/forums/viewtopic.php?f=14&t=54156&hilit=smartBMS and http://endless-sphere.com/forums/viewtopic.php?f=14&t=20971) (And frendly1uk.. did you mean cro...
by DrInnovation
Oct 22 2014 11:49am
Forum: Battery Technology
Topic: BMS sizing? SmartBMS quality? Group Buy?
Replies: 19
Views: 2170

Re: BMS sizing?

I see a bit of a problem from using two different charge voltages. A 7s bms is going to be expecting 4.2v per cell, but your talking about 4.05v per cell charge levels. There is a chance that the bms won't initiate balancing at such a low voltage. The actual board in question would need it's specif...
by DrInnovation
Oct 22 2014 9:15am
Forum: Battery Technology
Topic: BMS sizing? SmartBMS quality? Group Buy?
Replies: 19
Views: 2170

BMS sizing? SmartBMS quality? Group Buy?

I've built a pack to replace my SLAs with some of my UAV Lipos.. (at least untill I get around to building an 18650 pack). Looking at adding a BMS for piece of mind and reducing my work to checking it every now and then instead of every charge to and ensure per-cell low-voltage protection incase som...
by DrInnovation
Oct 20 2014 10:17am
Forum: Battery Technology
Topic: RC Lipo pack inspection, series/parallel charging, and lifespan/safety tips
Replies: 172
Views: 98293

Re: RC Lipo series charging tutorial

I of course made sure they were balanced before I made the rig. Regarding the chargeing: so the AH of the battery Dosent have to do with the Watts. Correct? It's just voltage and amps You are correct AH does not effect the Watts needed. AH of the battery is a question of capacity.. it effects how l...
by DrInnovation
Oct 19 2014 10:18pm
Forum: Battery Technology
Topic: RC Lipo pack inspection, series/parallel charging, and lifespan/safety tips
Replies: 172
Views: 98293

Re: RC Lipo series charging tutorial

DrInnovation thanks so much for the help! I think I will keep my set as P-S and will charge them in series as 6s 10ah battery. Do I have to balance the batteries? If the batteries are in balance and they stay like that do I have to balance charge them every time? I know people who have barely ever ...
by DrInnovation
Oct 19 2014 4:58pm
Forum: Battery Technology
Topic: RC Lipo pack inspection, series/parallel charging, and lifespan/safety tips
Replies: 172
Views: 98293

Re: RC Lipo series charging tutorial

..... As of now that is what I do. I run them first in parallel than in series and charge all 4 batteries in parallel. Question is can I just charge them in series instead of taking it apart and charging It in Parallel? If so I will put the balance leads the same way as the batteries themselves, fi...
by DrInnovation
Oct 19 2014 8:30am
Forum: Battery Technology
Topic: RC Lipo pack inspection, series/parallel charging, and lifespan/safety tips
Replies: 172
Views: 98293

Re: RC Lipo series charging tutorial

Hmm hopefully you have 4 3s 5000mah batteries.. neither order works with just 3 batteries.. With 4 then you can really connect in either order, you get 6 in one, half a dozen in the other -- only real issue is how you will charge them and how you balance them. You can 2 in parallel to get a 3s2p 100...
by DrInnovation
Oct 18 2014 5:25pm
Forum: Battery Technology
Topic: RC Lipo pack inspection, series/parallel charging, and lifespan/safety tips
Replies: 172
Views: 98293

Re: RC Lipo series charging tutorial

you will have to post up a picture of your battery pack. i have never seen lipo packs assembled with the cells wired in parallel. Cannot tell you about his pack.. but all my higher power lipos are parallel then serial. My thunersky 6000mah 11.1v are 3 parallel 2000mah cell pack, then put in series ...
by DrInnovation
Oct 14 2014 10:21pm
Forum: Battery Technology
Topic: Lithiums - mAh/100th V - Discharge Tests
Replies: 76
Views: 20059

Re: Lithiums - mAh/100th V - Discharge Tests

Find the discharge test data/graph for those headways at 30amps and see what the volt drop is. Compare to similar situation for your 18650s at whatever load you calculate they will see (~2.5A ?) Volt drop/sag under load can be a real spoiler in use. Did that already, question is if I should believe...
by DrInnovation
Oct 14 2014 7:32pm
Forum: Battery Technology
Topic: Lithiums - mAh/100th V - Discharge Tests
Replies: 76
Views: 20059

Re: Lithiums - mAh/100th V - Discharge Tests

I do have a lot of 18650 cells around, but getting to large numbers will mean a build will a mixed set of brands and a good bit more time than just buying some 8 headways.. Buying a lot of new cells for 18650 seems like asking for more work with little gain.. that won't save me much over the headwa...
by DrInnovation
Oct 14 2014 4:34pm
Forum: Battery Technology
Topic: SLA->Li upgrade options? Celllog 8S on SLA?
Replies: 8
Views: 1103

Re: SLA->Li upgrade options? Celllog 8S on SLA?

Just to follow on my own post/comments.. I tested the bike over the weekend. 30.5v worked but at 32v the controller would not respond at all on my lashout. Did do a road test just spinning the wheels on the stand.. but at least I think I can go with 29 or even 29.6v as the max volt on my new batteri...
by DrInnovation
Oct 14 2014 9:53am
Forum: Battery Technology
Topic: Lithiums - mAh/100th V - Discharge Tests
Replies: 76
Views: 20059

Re: Lithiums - mAh/100th V - Discharge Tests

.. Are there 18650 cells, other than A123, that could provide 30A of power in a 100mmx100mmx300mm space? yes ..many. That volume could hold over 100, 18650 cells. As you are requiring 24-29 volts, that would imply a 8s string of lico cells.( 3.7v each) So you could have 8s and 12 parallel, which wo...
by DrInnovation
Oct 13 2014 9:10pm
Forum: Battery Technology
Topic: Lithiums - mAh/100th V - Discharge Tests
Replies: 76
Views: 20059

Re: Lithiums - mAh/100th V - Discharge Tests

asking advice here would make you even more confused. you already seem misinformed about charging lithium so you now will be deliberately misinformed. I'm curious what I've said that suggest I'm misinformed about charging lithium.. Are there 18650 cells, other than A123, that could provide 30A of p...
by DrInnovation
Oct 13 2014 10:56am
Forum: Battery Technology
Topic: Lithiums - mAh/100th V - Discharge Tests
Replies: 76
Views: 20059

Re: Lithiums - mAh/100th V - Discharge Tests

Thanks for these plots.. While I see value in the standard discharge curves, they don't answer some important questions for me, at least not easily. I'm looking at building my first pack and one of the questions I face is the charge level. Interesting to know how much I loose by charging to a lower ...
by DrInnovation
Oct 05 2014 7:57pm
Forum: E-Vehicles General Discussion
Topic: Anyone here have a Volt?
Replies: 94
Views: 13428

Re: Anyone here have a Volt?

Thanks for the clarification Doctorbass. After writing this last night I decided to go to a local Chevy dealer today and take one for a test drive. I think the car drives amazingly well. The steering is the smoothest I have ever felt in any car. When I punched it, it pulled hard and steady. The int...
by DrInnovation
Oct 05 2014 9:58am
Forum: E-Bike General Discussion
Topic: Planning first ever build, am i on the right track?
Replies: 44
Views: 3772

Re: Planning first ever build, am i on the right track?

I realize this is an old thread.. but I'm curious if after a year you still recommend the bestgo Lifepo. Not seeing exactly the model you bought but http://www.electriccarpartscompany.com/10Ah-32V-3-5C-br-32L-05W-53H-in-br-82-12-135-mm-br-9-oz-255-g-br-Bestgo-Power-Pouch-Cell-br-EV-LiFePO4-Lithium-P...