Search found 312 matches

by redilast
Mar 27 2019 4:47am
Forum: Battery Technology
Topic: Which glue to join cells ?
Replies: 31
Views: 736

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: 336

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: 1102

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: 386

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: 20
Views: 1933

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: 20
Views: 1933

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: 20
Views: 1933

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: 20
Views: 1933

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: 1674

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: 990

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: 20
Views: 1933

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: 20
Views: 1933

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: 20
Views: 1933

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: 20
Views: 1933

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: 227

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: 3506

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: 5315

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: 282

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: 1074

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...
by redilast
Oct 21 2017 1:18am
Forum: Battery Technology
Topic: Is it OK to replace 40ah scooter batteries with 35ah?
Replies: 27
Views: 1622

Re: Is it OK to replace 40ah scooter batteries with 35ah?

Internal resistance is more important, because that generally dictates if the cell or battery can handle the same load as the other one. Some lead acid batteries used at heavy loads actually can have 1/2 their Ah capacity, its insane. If there is a datasheet or something for the batteries try to com...
by redilast
Oct 11 2017 12:49am
Forum: Battery Technology
Topic: Boston-Power Swing 5300 Li-ion cell test
Replies: 35
Views: 7903

Re: Boston-Power Swing 5300 Li-ion cell test

I have some of these laying around in an old medical device pack. It's got like 12 of these inside. The cycle life claims are most intriguing, but are the claims true? Cycling these 1000 times or so sure would take a while. Also I like the holders that are available for these cells. Could make for s...
by redilast
Aug 29 2017 6:01pm
Forum: Battery Technology
Topic: A little nervous I've underengineered my pack, thoughts?
Replies: 20
Views: 2187

Re: A little nervous I've underengineered my pack, thoughts?

I think it really depends on how long you think you might "burst" to 150A. If we are talking a few seconds here and there, no problem at all. If you think you might burst for a few minutes while going up a steep hill, then there might be a problem with overheating of the nickel strips. Here is a tes...
by redilast
Aug 20 2017 3:25am
Forum: Battery Technology
Topic: battery for ebike
Replies: 3
Views: 512

Re: battery for ebike

Open it up and see if there is an internal fuse. If not it probably blew out the mosfets or something.
by redilast
Aug 08 2017 11:01pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 615
Views: 74592

Re: kWeld - "Next level" DIY battery spot welder

After using google translate, it appears those tabs are not pure nickel, but nickel plated steel Can you post the text that make you think that, in German. I did not found any statement about material used. "vernickeltes Kaltband (Hilumin)" Google translates to: "Nickel plated cold strip (Hilumin)"...