Homemade Battery Packs

justadad1957 said:
the tinned copped braid looks like it can take some amps
keep your tire pressure gauge outta there
Click to expand...
Folding cardboard closed, protects wiring nicely.
But, my pressure gauge, CO2 pump, patch kit etc. all have non-conductive surfaces.
Plenty of room inside for charger & tool bag etc.
Also, the lower zipper "expands" the bag to add an extra couple inches, for more storage space.
(Fake lunch items ... etc.)
Total weight about 13lb.

Bonus:
NY & PA (USA)
Valu Home Center - a chain of hardware stores - has a nice allen wrench set for $1!
It covers all the EZip-IZip allen fittings.
It has a blue plastic body.
 
Wouln't a 6 pack cooler bag be insulated and trap any heat generated and ruin the batteries? Also, it may look inoccuous, but I'd be worried that instead of someone looking to steal batteries, kids & cops would be looking for the beer, except for Yogi Bear of course, who likes to steal the "picinic baskets".

Gary
 
Starson said:
Wouln't a 6 pack cooler bag be insulated and trap any heat generated and ruin the batteries? Also, it may look inoccuous, but I'd be worried that instead of someone looking to steal batteries, kids & cops would be looking for the beer, except for Yogi Bear of course, who likes to steal the "picinic baskets".

Gary
Click to expand...
I've never had any heat problems with Lipo or Li-ion.
Of course I rarely exceed 1C, more common is .3 - .5C.

Li-ion Lipo seem not to heat, during charge or discharge, unless "pushed" beyond, "recommended".
I've run this 37v pack for a steady 2 hours, and felt no noticeable heat.
Oddly, Lipo and Li-ion seem to output better when warmer. However, warmer while charging is bad!
Bag is nice for Winter, Li-ion - Lipo, are degraded by the cold, retaining ambient heat is a nice plus.
 
Starson said:
Wouln't a 6 pack cooler bag be insulated and trap any heat generated and ruin the batteries? Also, it may look inoccuous, but I'd be worried that instead of someone looking to steal batteries, kids & cops would be looking for the beer, except for Yogi Bear of course, who likes to steal the "picinic baskets".

Gary
Click to expand...
If I use my "6-Packer" on a front hub bike, I'll mount it between the bars and suspension fork.
No long wires to be broken , or spotted!

Of course I might have a partial, clear, water bottle, sticking out the edge.
As camo ...
 
Great new price on, 1-8S Lipo Battery Tester Low Voltage Buzzer Alarm. $3.29 w/shipping
Half the price of previous best price! I ordered another 5.

Displays total voltage and well as that of individual cell-bank.
Programmable low voltage alarm, audio-visual. (2.7-3.8v)

1-8S Lipo Battery Tester Low Voltage Buzzer Alarm RC 1S - 8s = <$4 w/shipping

1S-8S.JPG$3.29
Note: Claims accurate to within 1/100th Volt, actual, from several, is a few 100ths.
Total voltage accurate, cell accuracy varies.

I use one as an "on bar" volt-fuel gauge. Rigged into throttle, (voltage to battery level leds).
Up to 30v 1S meter, just attach to neg - pin 1 and pin 2.
Use multiple to monitor, larger than, 8S packs.
 
SamTexas said:
Good price.
Can you turn it off or is it always on once connected to the battery pack?
Click to expand...
No switch.
Put a switch on pin #1, (neg), shuts it off.
Or ... unplug from balance connector.
Or ... Leave plugged in, might use 1 watt ...
error ".24% per day, that is 400+ days on a 10ah pack." error

OOPS! 1 watt usage ... more like 240 hours ... Sorry!
Watt usage should be, much, less than that, but don't have instruments that sensitive.
 
Sorry! My numbers were off!
Doing a test now, might be a couple days before accurate results.

Preliminary results:
8 hours;
Seems to draw power from S1-S2 only.
4.32ah cells down .02v. (Meter not 1/1000 capable, might be .011 to .029)
Will revise at 24 hour mark.
 
They generally all do that.
The celllog 8s draws power from 6 of 8 cells, but can be modified to draw from all 8. May be an interesting alternative.

The problem with these units is that you have to repeatedly connect and disconnect them if you don't want them killing your first couple cells. Same problem with 95% of the BMSes on the market out there.

This is why i prefer to use LVC on my controller. I am surprised that nobody has came up with a standalone LVC unit that uses a DC-DC converter to power it.
 
1-8S Lipo Battery Tester Low Voltage Buzzer Alarm
24hr report:
4.32ah battery
Drained .1v - 24 hours
Draws power from S1 and S2 only
.1v might not seem like much, but that is more than 10% capacity of 2 banks, which would lower entire pack usable by 10%
Of course, with a 20ah pack, that would be a mere 2% per day ...

Still, I would have to recommend, that item should be used only during pack usage, or to check pack occasionally.

A switch or momentary contact button, on neg pin, would easy on-off or allow quick check.

1-8S Lipo Battery Tester Low Voltage Buzzer Alarm RC 1S - <$3.29 w/shipping
 
Negative pin would still allow for a bit of draw. The question is, how much.
I know you haven't been on ES too long, but i have seen the negative pin thing not work many times in a lot of threads.

Real unfortunate. We need a BMS or LVC unit that only turns on *when the bike power is on!!!*, novel concept right?

This is why i gave up on the idea of constant per cell level LVC / monitoring early into my build. So i just chop a little voltage off the top and bottom of my charges.
 
DrkAngel said:
1-8S Lipo Battery Tester Low Voltage Buzzer Alarm
24hr report:
4.32ah battery
Drained .1v - 24 hours
Draws power from S1 and S2 only
.1v might not seem like much, but that is more than 10% capacity of 2 banks, which would lower entire pack usable by 10%
Of course, with a 20ah pack, that would be a mere 2% per day ...

Still, I would have to recommend, that item should be used only during pack usage, or to check pack occasionally.

A switch or momentary contact button, on neg pin, would easy on-off or allow quick check.
Click to expand...
Wow, DrkAngel; That device looks great! Where can I buy it? Do you have a link? How much does it cost?

FA
 
DrkAngel said:
Great new price on, 1-8S Lipo Battery Tester Low Voltage Buzzer Alarm. $3.29 w/shipping
Half the price of previous best price! I ordered another 5.

Displays total voltage and well as that of individual cell-bank.
Programmable low voltage alarm, audio-visual. (2.7-3.8v)

1-8S Lipo Battery Tester Low Voltage Buzzer Alarm RC 1S - $3.29 w/shipping

file.php
$3.29
Note: Claims accurate to within 1/100th Volt, actual, from several, is a few 100ths.
Total voltage accurate, cell accuracy varies.

I use one as an "on bar" volt-fuel gauge. Rigged into throttle, (voltage to battery level leds).
Up to 30v 1S meter, just attach to neg - pin 1 and pin 2.
Use multiple to monitor, larger than, 8S packs.
Click to expand...
1-8S Lipo Battery Tester Low Voltage Buzzer Alarm
24hr report:
4.32ah battery
Drained .1v - 24 hours
Draws power from S1 and S2 only
.1v might not seem like much, but that is more than 10% capacity of 2 banks, which would lower entire pack usable by 10%
Of course, with a 20ah pack, that would be a mere 2% per day ...

Still, I would have to recommend, that item should be used only during pack usage, or to check pack occasionally.

A switch or momentary contact button, on neg pin, would easy on-off or allow quick check.
 
Those devices are what's known as a battery-unbalancer. :)
 
Why would they do that?

Sorry, lipo no0b here. (Ask me about SLA's and I'll talk your ear off; and yes, SLA's are not fashionable and eventually I will be ditching them).

FA
 
liveforphysics said:
Those devices are what's known as a battery-unbalancer. :)
Click to expand...
Floont said:
Why would they do that?

Sorry, lipo no0b here. (Ask me about SLA's and I'll talk your ear off; and yes, SLA's are not fashionable and eventually I will be ditching them).

FA
Click to expand...
The meter draws power from S1 and S2 only, (bank 1 & 2).
Good condition Li-ion - Lipo tend to discharge and recharge at a fairly constant rate.
Meaning?
A Li-ion Lipo pack will discharge-recharge back to the same "equalized" voltage, (all cells same voltage), without a balance-equalization device.
An alternate draw on 2 banks will cause those 2 banks to recharge to a slightly lower voltage, every cycle becoming worse.
Unless ... you use a balance-equalization charger.
 
DrkAngel said:
Floont said:
Why would they do that?..
Click to expand...
The meter draws power from S1 and S2 only, (bank 1 & 2)...An alternate draw on 2 banks will cause those 2 banks to recharge to a lower voltage, every cycle becoming worse...
Click to expand...
Thanks for the explanation.
I feel like rushing right out and purchasing an arm-full of them. :roll:
 
liveforphysics said:
Those devices are what's known as a battery-unbalancer. :)
Click to expand...
DrkAngel said:
Floont said:
Why would they do that?

Sorry, lipo no0b here. (Ask me about SLA's and I'll talk your ear off; and yes, SLA's are not fashionable and eventually I will be ditching them).

FA
Click to expand...
The meter draws power from S1 and S2 only, (bank 1 & 2).
Good condition Li-ion - Lipo tend to discharge and recharge at a fairly constant rate.
Meaning?
A Li-ion Lipo pack will discharge-recharge back to the same "equalized" voltage, (all cells same voltage), without a balance-equalization device.
An additional draw on 2 banks will cause those 2 banks to discharge and recharge to a lower voltage, every cycle becoming worse.
Unless ... you use a balance-equalization charger.
Click to expand...
Of course, if only on during battery usage, (20ah pack), it would take a dozen cycles to produce a 1% variance.
I would certainly recommend an equalization at least that often.

Note: When used as a voltage meter only, voltage draw is over entire pack, and of insignificant drain.
If wired into throttle meter LED voltage, it will disengage when power to controller is disconnected.
Voltage limit, in this mode is only 30v.
Great for OEM SLA, Lipo - Li-ion up to 25.9v, LiFe, Nimh etc
 
DrkAngel said:
...If wired into throttle meter LED voltage, it will disengage when power to controller is disconnected...
Click to expand...
Hm. That actually seems clever.

FA
 
Balancing-charging a 8S-10S-12S LI- pack!
Found a nice little item that allows 1 step charging-balancing of larger Li-ion Lipo etc. packs, from a 6S charger.
5pcs XH 6S to 2XH 6S Silicone Wire 22AWG

6-12balance.JPG

Simply split pack int equal halves, 12S into 2-6S, etc.
Use of a quick connect, recommended, 100a T-Plug, or other.

No, it is not necessary to use all 6 balance pins.
On the iMax B6, connect neg pin to Neg pin, leave additional on Pos end empty.
10S as 2-5S or 8S as 2-4S works fine. (As tested on iMax B6 and B8.)

Cautions! Disconnect battery from controller, and separate battery, before attaching balance plugs.
Disconnect charger and balance wires before reconnecting battery! (6-22awg silicone wires will surge a nasty current!)
 
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