Search found 317 matches

by redilast
May 06 2019 11:50pm
Forum: Battery Technology
Topic: Rebuilding a Segway I2 Battery
Replies: 5
Views: 400

Re: Rebuilding a Segway I2 Battery

I'm pretty sure they are 18650 LiFePo4's.
by redilast
May 06 2019 11:16pm
Forum: Battery Technology
Topic: Actual Test of Pure Nickel Heat?
Replies: 24
Views: 1174

Re: Actual Test of Pure Nickel Heat?

Thats super useful thanks alot btw, for how long did you "stay" on each current for the test? I did the test a couple years ago. It was either 5 or 10 minutes. Certainly long enough to heat soak the material. Keep in mind that real world results will vary a little. This testing was done with the ni...
by redilast
May 06 2019 4:21am
Forum: Battery Technology
Topic: Actual Test of Pure Nickel Heat?
Replies: 24
Views: 1174

Re: Actual Test of Pure Nickel Heat?

rg12 wrote:
May 04 2019 9:01am
I will be using a 6.75mm wide 0.2mm thick nickel for constant current of about 6.5A
Will it not go hot enough while it's sitting on the cell holder plastic?
You will be just fine. Likely your nickel will be <10C above ambient temperatures at that current.
by redilast
May 06 2019 4:18am
Forum: Battery Technology
Topic: Actual Test of Pure Nickel Heat?
Replies: 24
Views: 1174

Re: Actual Test of Pure Nickel Heat?

Yes, I've done testing:

Image
by redilast
May 06 2019 4:15am
Forum: Battery Technology
Topic: Anyone dealt with Tech Direct Inc. LG Chem Modules
Replies: 25
Views: 3177

Re: Anyone dealt with Tech Direct Inc. LG Chem Modules

Is this the same company that was selling Leaf modules that only had ~50% of original capacity? In general the industry deems anything in the 70-80% of original capacity range to be end of life (EOL). So you shouldn't buy anything like that. What capacity were the cells originally and what is their ...
by redilast
Mar 27 2019 4:47am
Forum: Battery Technology
Topic: Which glue to join cells ?
Replies: 31
Views: 1355

Re: Which glue to join cells ?

When I have to glue cells together I use Quick Grip. It works great, highly recommended! Been using it for years. Part number 873388
by redilast
Mar 12 2019 1:19am
Forum: Battery Technology
Topic: The proper (fastest) way solder 18650 cells
Replies: 4
Views: 575

Re: The proper (fastest) way solder 18650 cells

The best way to soldier 18650's is not to solder them at all. Spot weld.
by redilast
Dec 29 2018 1:12am
Forum: Battery Technology
Topic: Power tool batteries...interchangeability ?
Replies: 29
Views: 1806

Re: Power tool batteries...interchangeability ?

Black and Decker 36v/40v and Die Hard 40v packs are the same thing. At least the versions that look the same are the same.

Ryobi and craftsman 4v packs (the 1x18650 ones) are the same.
by redilast
Jul 22 2018 4:27pm
Forum: Battery Technology
Topic: bought 3 batteres. Shows 3,58V on every 4p. Scam?
Replies: 8
Views: 646

Re: bought 3 batteres. Shows 3,58V on every 4p. Scam?

~3.6v is very typical for new cells. They made SOC for shipping even more strict in the past couple of years I think its <30% SOC now.
by redilast
Jun 13 2018 10:35pm
Forum: Large EV General Discussion
Topic: A simple but practical and cheap EV range extender?
Replies: 21
Views: 4267

Re: A simple but practical and cheap EV range extender?

Completely incorrect just as I originally guessed. Just took a clamp meter and tested the car under various load conditions. It draws 25A upon startup (when some pump is running, presumably some hydraulic pump for breaks/power steering). Then settles down to around 20A with headlights on. This is c...
by redilast
May 18 2018 4:49am
Forum: Large EV General Discussion
Topic: A simple but practical and cheap EV range extender?
Replies: 21
Views: 4267

Re: A simple but practical and cheap EV range extender?

Sorry, you are not making sense, and I believe you are incorrect. DC/DC converter literally dumps power to the 12V + and - terminals of the battery. These same 12v battery + and - connections have cables to the cars chassis which then powers accessories. Right. So if you measure power to/from the b...
by redilast
May 11 2018 3:48am
Forum: Large EV General Discussion
Topic: A simple but practical and cheap EV range extender?
Replies: 21
Views: 4267

Re: A simple but practical and cheap EV range extender?

That doesn't make sense to me, unless there is a bypass that allows power to flow from the DC/DC directly to the accessories and not through the battery. The battery is not an energy source, and no power flows "through" it. In a hybrid it only provides power to start the car (and power for lights e...
by redilast
May 09 2018 10:24pm
Forum: Large EV General Discussion
Topic: A simple but practical and cheap EV range extender?
Replies: 21
Views: 4267

Re: A simple but practical and cheap EV range extender?

I might try connecting my DC clamp meter to the 12V battery cable so I can see what kind of power that puppy is supplying with the AC and heat on etc. You have to put the clamp on the output of the DC/DC not the battery. Why? The fans, lights, radio are all drawing power through the battery which i...
by redilast
May 09 2018 10:20pm
Forum: Battery Technology
Topic: Tool battery for extra range
Replies: 22
Views: 2591

Re: Tool battery for extra range

Regarding low voltage protection, that would only work on batteries where the power flows through mofets. What I'm seeing in many newer batteries is they don't send the power through mosfets (this increases resistance and voltage loss) but instead rely on the tool to sense when the battery is low an...
by redilast
May 09 2018 10:12pm
Forum: Large EV General Discussion
Topic: Finally, Your Next Car Could Be A 3D-Printed Electric Car
Replies: 1
Views: 1144

Re: Finally, Your Next Car Could Be A 3D-Printed Electric Car

70Kmph max speed. Couldn't take it on the highway. If it was highway legal and was $7500 it would be a free car for those in the US, because there is a $7500 federal rebate on Electric cars lol
by redilast
May 09 2018 9:56pm
Forum: Large EV General Discussion
Topic: A simple but practical and cheap EV range extender?
Replies: 21
Views: 4267

Re: A simple but practical and cheap EV range extender?

The 12V is used to power 12V items. Not major power loads. So it powers fans and electronics. The biggest load is probably headlights. For example on the A/C the compressor motor runs on the mail traction battery at 400V or whatever, but the controls and air-moving fans will power on 12V. The best ...
by redilast
May 09 2018 9:53pm
Forum: Large EV General Discussion
Topic: A simple but practical and cheap EV range extender?
Replies: 21
Views: 4267

Re: A simple but practical and cheap EV range extender?

I might try connecting my DC clamp meter to the 12V battery cable so I can see what kind of power that puppy is supplying with the AC and heat on etc. You have to put the clamp on the output of the DC/DC not the battery. Why? The fans, lights, radio are all drawing power through the battery which i...
by redilast
May 09 2018 2:35am
Forum: Large EV General Discussion
Topic: A simple but practical and cheap EV range extender?
Replies: 21
Views: 4267

Re: A simple but practical and cheap EV range extender?

5Kw could be ~500x 18650's which would be sub 25KG just for the cells or around 55lbs. I might try connecting my DC clamp meter to the 12V battery cable so I can see what kind of power that puppy is supplying with the AC and heat on etc. I believe the real killer of the battery is the liquid chilled...
by redilast
May 08 2018 5:47pm
Forum: Large EV General Discussion
Topic: A simple but practical and cheap EV range extender?
Replies: 21
Views: 4267

A simple but practical and cheap EV range extender?

So all production EV's I'm aware of use a 12V flooded lead acid battery which is charged by a DC to DC converter off the main Li-ion pack. This 12v battery powers lights, fans, accessories, and other car electronics. Some articles I read suggested that it may even be powering the heating and cooling...
by redilast
May 08 2018 5:34pm
Forum: Battery Technology
Topic: 17Ah GA pack shuts down after 2.5Ah
Replies: 3
Views: 375

Re: 17Ah GA pack shuts down after 2.5Ah

Need more information. What is the BMS cutoff voltage? What temperature? What is your average current consumption?
by redilast
May 08 2018 5:33pm
Forum: Battery Technology
Topic: New battery pack build.....25R, 30Q or VTC6?
Replies: 24
Views: 6574

Re: New battery pack build.....25R, 30Q or VTC6?

I'd say make sure the cell continuous amp rating is at least double your actual continuous amp draw, or your pack will have a very short cycle life of maybe only 100-150 cycles if pushed to their limit. Also consider the Sanyo NSX. I prefer it over the 25R, its a bit more expensive, but has lower re...
by redilast
Apr 30 2018 5:05am
Forum: Battery Technology
Topic: Highest capacity 18650 cells
Replies: 68
Views: 8677

Re: Highest capacity 18650 cells

LG M36 is the highest capacity readily available 18650 on the market. 3600mAh, 10A rated.

Sanyo GA, Samsung 35W, LG MJ1 are all 3500mAh and are close.
by redilast
Mar 14 2018 5:33am
Forum: Battery Technology
Topic: battery life @ supercharging dependent of heat - Discussion
Replies: 2
Views: 388

Re: battery life @ supercharging dependent of heat - Discussion

Any battery will prefer to spend its life at 25'C. Charging at 2C is no different to discharging at 2C - the heat is mainly coming from I^2R losses in the current collectors. The degradation is quicker at high states of charge too - more reactive species present. I agree, the heat dissipated will b...
by redilast
Jan 10 2018 5:44pm
Forum: Battery Technology
Topic: Given 80 90 100 % what is the sweet spot?
Replies: 13
Views: 1383

Re: Given 80 90 100 % what is the sweet spot?

I agree, it depends on your needs. The military often charges their long life Li-ion batteries to 3.92v per cell, which is around a 70% SOC providing much longer cycle life, and basically eliminating the CV stage of charging. NASA in some applications in space has used 20-30% DOD and achieved 10's o...