New Battery for my bike

greeno

Well-Known Member
Region
USA
City
San Diego
I got my present ride from Pushkar last year and as you guys know I built it up from the frame and motor. Well I wanted to build the largest Ahr Battery that would comfortably fit so I went with a 52v 10 pack and built a 34.5ahr battery.
Well after riding this bike for awhile now and it being more economical than the old BBSHD I rarely get it down to even 50% capacity after a long ride so I decided to go a little smaller, yes I said smaller, and build up a combo pack. What I mean by that is when you spot weld up these batteries you get one shot at it as you can't really tear it apart to go with a different configuration and use those same batteries without a whole lot of problems. Repairing a single battery in a group yeah but you gotta cut the jumpers to that cell and remove in place if that makes any sense. Have not had to repair any of the battery packs that I have built for myself or friends but I have wrenched on a few Luna packs where the jumper flexed and broke off or a sensing wire came loose from the solder, but I digress.

Back to the combo pack. I wanted to go smaller but not to small so I designed a 7 pack ( 24ahr ). So if after using it I find it is not sufficient enough in range I would easily be able to open it back up add another cell to each of the 14 groups thus making it a 8 pack ( 28ahr ). The original configuration would stay the same as I would just be adding cells and jumpers along the outer perimeter in such a way as to keep it compact and not change the overall shape to much. Still using the Sanyo GA batteries at 3450mahr/10a discharge and with a minimum of (10) jumpers from group to group to keep the current flow very low. Controller is limited to 30a, BMS also, so doing the math at full load 1500w I got about 30a running from group to group and ten jumpers per so it equates out to about 3a per nickel jumper so not much heat which is a killer for battery's. Typically never run a full load anyway so it's kinda mute.
Reducing the size of the battery down should save me about 6 lbs and I was 66lbs before with the larger battery. It will be interesting to see how my range compares with my buddys battery's as their's are the bigger 34.5ahr models. Battery is charging up as we speak, or type, so I will get it out on a ride here pretty quick to see if I'm a hero or a zero.
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pushkar

Well-Known Member
New battery pack is pretty rad.

How about an upgrade to 3500W, so even if you don't have range, you get get to your destination faster than "your friends" :)

Let me know once hte pack is built and I can upgrade your motor remotely. Post your experience here :)
 

greeno

Well-Known Member
Region
USA
City
San Diego
Are you kidding me 1500w is P L E N T Y for this guy. It's all about the range for me. If I want speed I'll take my Ford F350 for a spin, oh wait that won't do it either my mistake. No need for any upgrades I don't think as the motor purrs like a lion. Hope your doing well. Mike
 

greeno

Well-Known Member
Region
USA
City
San Diego
Finally got the bag for my battery and fit it up on the bike. Looks small compared to the previous one and lighter. Went for a quick ride down in the canyon and couldn't really tell difference in losing some lbs, maybe a little less shifting around, more secure. That was never an issue before so I'll ride with it for a bit and see tomorrow how it goes compared to my friends range distance and voltage at the end of the ride. Cost about 2 bills less to make and 6 lbs lighter so less is more right?
Trying to post a pic but it comes up 90 degrees out. I'll mess with it later.

Resized the pics and all good. Original Larger 34.5ahr battery and bag.

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"New" smaller 24ahr battery and bag.
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Drum roll please.......
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Haha just kidding. Gonna tell my buddy's that and let them figure out what's what.
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Last edited:

Merle Nelson

Well-Known Member
Region
USA
When you're into ebikes being able to build your own custom batteries is pretty top notch.

Fun to see and to read some of your thinking on it.
 

greeno

Well-Known Member
Region
USA
City
San Diego
Thanks for the support. Being a retired Electrical Contractor gives me the background to pursue the battery technology. Used to specialize in Industrial jobs and High Voltage splicing as well as standard commercial projects. Kept the company small to effectively stay on top of things to keep quality high on whatever work we were doing. Even being an owner I was hands-on on in all aspects from start to finish. Sold the Company back in 2012 and retired a little early so all I got is time. If I can't find what I need I have a tendency to make it. Seems like a good group of guys on this forum and not a lot of "Drama" which I don't really want to be a part of. If I can post up something that helps someone else that's my motivation. I definitely pick up stuff from other members too. Riding in a few so we'll see how this battery performs and I'll decide weather or not to modify it to the 8 pack. Hopefully this will work for 90% of the riding I do and if I need mega range I got my bigger pack. Later gents.
 

greeno

Well-Known Member
Region
USA
City
San Diego
Looks like I'm going to stay with just the 7 pack battery for the time being. Rode hard for 21 miles a lot of up and down and all single track and I only used 4.3v. Started at 58.5 and ended up at 54.2v and had responsive power when I needed it for climbing up the canyon we use to drop into the main riding area.
Bike did feel more responsive overall so I guess it did make i difference in shading the 6lbs. When my buddy pulled my bike off the rack he made mention on it feeling a little lighter.
Now of course my friends have "placed their orders" for the lighter model pack seeing how we can still get the range we wanted. Already got the BMS's so I'll order up the batteries mañana. We'll keep the bigger battery's for the Joshua Tree area or dropping down into the desert from mcCain valley and climbing back up.
 

greeno

Well-Known Member
Region
USA
City
San Diego
Tested out the "New" smaller Ahr battery I made last week and it worked out great.
Went for a typical jaunt from my house down into the canyon and up through some valleys all single track with only about 1k vertical ft of climbing. Mostly flat rollers so I could get decent speed and get the heart racing a bit.
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Started off with a clean slate and a mostly full charge.
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Got back later and had this on the display.
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Level 1 assist 10%
Level 2 assist 60%
Level 3 assist 30%

Easiest effort to drop 6 lbs I ever did. Gonna be my main pack for now I think it should work out nicely.
Tryin to figure out how to post up a quick little GoPro video I did last week gonna try to put some tunes to it so as not to bore you guys to much. Till later.