Building a custom battery pack
#1
Senior Member
Thread Starter
Building a custom battery pack
Searched but didn't find much. Any advice or suggested links or forums to check out for advice on how to build a custom battery pack for lighting? Would like to increase my battery pack and have a back up on hand. Would like to build an 8.4v pack with 4-6 18650 cells to get 6200+ mah in a waterproof container. Seen some on Amazon but would like some experienced feedback or direction to another forum. Looked in in Candle Power forums but didn't find anything specific. Specific questions at this point:
How well do the generic Amazon battery housings work? Something like this as example
Do those have adequate low voltage protections?
Could I charge directly in the housing or should I look at getting a separate charger to charge each cell directly.
If I go the charger route can I get one to use the much cheaper un protected cells?
Would love to find a housing that has electronics to protect the cells from discharge and use as charging base using unprotected cells and be able to use my current cheap chargers.
How well do the generic Amazon battery housings work? Something like this as example
Do those have adequate low voltage protections?
Could I charge directly in the housing or should I look at getting a separate charger to charge each cell directly.
If I go the charger route can I get one to use the much cheaper un protected cells?
Would love to find a housing that has electronics to protect the cells from discharge and use as charging base using unprotected cells and be able to use my current cheap chargers.
#2
Galveston County Texas
Join Date: Nov 2007
Location: In The Wind
Posts: 33,219
Bikes: 02 GTO, 2011 Magnum
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 1349 Post(s)
Liked 1,243 Times
in
621 Posts
I use these:
$13.82 8.4V 6000mAh Rechargeable 4*18650 Battery Pack - IPX6 waterproof at FastTech - Free Shipping
$13.82 8.4V 6000mAh Rechargeable 4*18650 Battery Pack - IPX6 waterproof at FastTech - Free Shipping
__________________
Fred "The Real Fred"
Fred "The Real Fred"
#3
Zoom zoom zoom zoom bonk
Join Date: Sep 2006
Location: New Zealand
Posts: 4,624
Bikes: Giant Defy, Trek 1.7c, BMC GF02, Fuji Tahoe, Scott Sub 35, Kona Rove, Trek Verve+2
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 551 Post(s)
Liked 722 Times
in
366 Posts
Searched but didn't find much. Any advice or suggested links or forums to check out for advice on how to build a custom battery pack for lighting? Would like to increase my battery pack and have a back up on hand. Would like to build an 8.4v pack with 4-6 18650 cells to get 6200+ mah in a waterproof container.
Kai do 2/4/6/8 batteries in a rugged rubber pack. They are excellent. Grab a 2 cell for backup.
https://kaidomain.com/bike-lights-and.../battery-packs
#4
Senior Member
Thread Starter
Oh, I wouldn't build one by soldering. Was thinking more of finding a good case with electronics in in the top of the case and then using stand alone cells (4 or 6) inserted in case like you would AA batteries. I would source case, batteries and possibly charger separately. For long rides could then carry 4 back up cells just like carrying 4 extra AA batteries and just drop in case when first ones discharge.
But both the complete packs you both mentioned seem like less hassle and I will look into both of those.
Thanks for the input!
But both the complete packs you both mentioned seem like less hassle and I will look into both of those.
Thanks for the input!
#5
Senior Member
Searched but didn't find much. Any advice or suggested links or forums to check out for advice on how to build a custom battery pack for lighting? Would like to increase my battery pack and have a back up on hand. Would like to build an 8.4v pack with 4-6 18650 cells to get 6200+ mah in a waterproof container. Seen some on Amazon but would like some experienced feedback or direction to another forum. Looked in in Candle Power forums but didn't find anything specific. Specific questions at this point:
How well do the generic Amazon battery housings work? Something like this as example
Do those have adequate low voltage protections?
Could I charge directly in the housing or should I look at getting a separate charger to charge each cell directly.
If I go the charger route can I get one to use the much cheaper un protected cells?
Would love to find a housing that has electronics to protect the cells from discharge and use as charging base using unprotected cells and be able to use my current cheap chargers.
How well do the generic Amazon battery housings work? Something like this as example
Do those have adequate low voltage protections?
Could I charge directly in the housing or should I look at getting a separate charger to charge each cell directly.
If I go the charger route can I get one to use the much cheaper un protected cells?
Would love to find a housing that has electronics to protect the cells from discharge and use as charging base using unprotected cells and be able to use my current cheap chargers.
Not sure if the circuit inside the case has a low voltage protection but likely it does. I use mine with unprotected batteries but I rarely ride more than a couple hours at night. Regardless, you want to take the top off the case after you are done riding so the circuit inside the battery for the USB attachment doesn't discharge and kill the batteries while being stored. Yes you charge with a regular battery pack charger but better to use a separate 4-bay cell charger so all cells get charged to their maximum levels. I believe there is a 6-cell version but you might have to search a bit to find one. That said if you have the 4-cell version you can always carry two extra cells along and if the 4 cells start to get too low you can take them out and operate on just two cells ( when in series ) It will work with just two cells, just not as long of course.
Now if you wanted to be extra safe and yet save a few $$ you could buy 2 unprotected cells and 2 protected cells. Put one protected cell in series with one unprotected cell ( one on each side ) and should provide an extra bit of voltage cutoff protection. I buy my loose brand name cells from Orbtronic ( based in Fla. USA ) good prices on the brand name cells and quick shipping. ( my choice was the LG MJ-1 3500mAh unprotected cells.
#6
Senior Member
Thread Starter
I have one of the Trustfire 4-cell holders. It works but I don't use mine on the frame of the bike. I use mine to power a helmet light and put the pack in my hydration backpack. I've heard of people using them on the frame. Some have complained that if you hit a big bump that the lamp might can go out ( if the batteries move too much ) Never had any problems myself.
Not sure if the circuit inside the case has a low voltage protection but likely it does. I use mine with unprotected batteries but I rarely ride more than a couple hours at night. Regardless, you want to take the top off the case after you are done riding so the circuit inside the battery for the USB attachment doesn't discharge and kill the batteries while being stored. Yes you charge with a regular battery pack charger but better to use a separate 4-bay cell charger so all cells get charged to their maximum levels. I believe there is a 6-cell version but you might have to search a bit to find one. That said if you have the 4-cell version you can always carry two extra cells along and if the 4 cells start to get too low you can take them out and operate on just two cells ( when in series ) It will work with just two cells, just not as long of course.
Now if you wanted to be extra safe and yet save a few $$ you could buy 2 unprotected cells and 2 protected cells. Put one protected cell in series with one unprotected cell ( one on each side ) and should provide an extra bit of voltage cutoff protection. I buy my loose brand name cells from Orbtronic ( based in Fla. USA ) good prices on the brand name cells and quick shipping. ( my choice was the LG MJ-1 3500mAh unprotected cells.
Not sure if the circuit inside the case has a low voltage protection but likely it does. I use mine with unprotected batteries but I rarely ride more than a couple hours at night. Regardless, you want to take the top off the case after you are done riding so the circuit inside the battery for the USB attachment doesn't discharge and kill the batteries while being stored. Yes you charge with a regular battery pack charger but better to use a separate 4-bay cell charger so all cells get charged to their maximum levels. I believe there is a 6-cell version but you might have to search a bit to find one. That said if you have the 4-cell version you can always carry two extra cells along and if the 4 cells start to get too low you can take them out and operate on just two cells ( when in series ) It will work with just two cells, just not as long of course.
Now if you wanted to be extra safe and yet save a few $$ you could buy 2 unprotected cells and 2 protected cells. Put one protected cell in series with one unprotected cell ( one on each side ) and should provide an extra bit of voltage cutoff protection. I buy my loose brand name cells from Orbtronic ( based in Fla. USA ) good prices on the brand name cells and quick shipping. ( my choice was the LG MJ-1 3500mAh unprotected cells.
Will probably wait till next season as I just ordered one of the cheap Chinese premade packs referenced above that claims like 8400 mah and ipx8 water protection. Though price was higher due to US battery postage surcharge, final price in the low $20 range. The original that came with my light is still going strong and charges last about 2.5 hours and the one I ordered will be on a back up light. otoh maybe this can be a winter project!
Last edited by Paniolo; 12-03-20 at 03:49 PM. Reason: clarification
#7
Senior Member
Thanks for the real world review! Exactly what I would like to do, get much higher capacity and quality along with ability to just replace cells as they go bad. I like having a component approach for case, batteries and charger allowing you to build a much safer, higher quality battery with 2-3x the capacity and run time. For use on my road bike bars would like to frame mount the battery, so road shocks or bumps causing power interruption/ shut down would be a problem.
Will probably wait till next season as I just ordered one of the cheap Chinese premade packs referenced above that claims like 8400 mah and ipx8 water protection. Though price was higher due to US battery postage surcharge, final price in the low $20 range. The original that came with my light is still going strong and charges last about 2.5 hours and the one I ordered will be on a back up light. otoh maybe this can be a winter project!
Will probably wait till next season as I just ordered one of the cheap Chinese premade packs referenced above that claims like 8400 mah and ipx8 water protection. Though price was higher due to US battery postage surcharge, final price in the low $20 range. The original that came with my light is still going strong and charges last about 2.5 hours and the one I ordered will be on a back up light. otoh maybe this can be a winter project!
#8
Junior Member
Join Date: Dec 2020
Location: Nr. Helston, Cornwall. U.K.
Posts: 13
Bikes: One whole Raleigh mountin bike,and lots of other bit,parts,and left over cut offs.
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
18650's are used as back up for lots of devices now but I have always been put off by the cost to make up a big enough bank. I find that lead acid although heavy is more cost effective.
I am working on a bike trailer to tow two old car batteries, that still have life. Its surprising how long they last drawing about 12 amps.
I am working on a bike trailer to tow two old car batteries, that still have life. Its surprising how long they last drawing about 12 amps.
#10
Senior Member
Join Date: Feb 2008
Location: Peoria, IL
Posts: 4,464
Mentioned: 86 Post(s)
Tagged: 0 Thread(s)
Quoted: 1824 Post(s)
Liked 3,366 Times
in
1,572 Posts
Likes For steelbikeguy:
#11
Junior Member
Join Date: Dec 2020
Location: Nr. Helston, Cornwall. U.K.
Posts: 13
Bikes: One whole Raleigh mountin bike,and lots of other bit,parts,and left over cut offs.
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
Brakes
If I made the drive fixed (no freewheel) I would have the solution, Motor overrun.. but couldn't then pedal it.
If I found a freewheel that locked the problem would be solved. Any Ideas ??
My aim is to have a sort of mobility machine for the elderly with arthritic knees, like me. !!
Chris.
#12
Senior Member
Join Date: Feb 2008
Location: Peoria, IL
Posts: 4,464
Mentioned: 86 Post(s)
Tagged: 0 Thread(s)
Quoted: 1824 Post(s)
Liked 3,366 Times
in
1,572 Posts
Yes Steve, Thanks for the thought., I was thinking about that one, especially in the rain.
If I made the drive fixed (no freewheel) I would have the solution, Motor overrun.. but couldn't then pedal it.
If I found a freewheel that locked the problem would be solved. Any Ideas ??
My aim is to have a sort of mobility machine for the elderly with arthritic knees, like me. !!
Chris.
If I made the drive fixed (no freewheel) I would have the solution, Motor overrun.. but couldn't then pedal it.
If I found a freewheel that locked the problem would be solved. Any Ideas ??
My aim is to have a sort of mobility machine for the elderly with arthritic knees, like me. !!
Chris.
I'd be inclined to go with a more modern battery technology. Battery charging is always the dangerous part of working with batteries. I used to work at a place that built large ni-cad battery packs for aerospace, and we treated them like they were dynamite whenever they were charged. NiMH batteries are safer to charge than lithium ion batteries and are lighter than lead-acid or ni-cad batteries. I'm not sure if they are cheaper than lithium ion, and they will certainly be more expensive than lead-acid.
Generally, it's not bad to repurpose something that is already in production. Maybe use some battery modules made for power tools?
Steve in Peoria
#13
Senior Member
Join Date: Jul 2006
Location: TX
Posts: 522
Bikes: Downtube IX NS&FS, Dahon Speed8Pro/Matrix/Curve, Brom S2L,Montague Para, ICE-XL w/Rollie/Schlumpf, Trident Spike, ebikes, BFSatRDay
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 172 Post(s)
Liked 95 Times
in
81 Posts
The EndlessSphere guys live this topic. Check them out.