Ideas on ebike charging and use?

[bart_dood]

Hi Folks,

I have just partly rebuilt my ebike; I posted it in the builds section a couple of years ago but here's a pic of it now. I changed the motor from a rear DD golden motor to a golden motor mini, 36v front mounted unit instead. I wanted to reduce the weight and also be able to pedal the bike normally with no assist without the large drag of the DD motor. You can see I built my own fiberglass battery and controller housing in grey which keeps everything tidy.

So I'm looking for some advice from people out there on simplifying or changing perhaps my battery layout and how I recharge. Currently I have 4 zippy lipo packs, 6 series 5 amp hour, I wire them two in parallel and then both sets in series to give me 48volts at 10 amp hour capacity, they sit inside the housing I made to fit in the frame.
I normally use the bike to commute to work, its fairly hilly so the assist helps a lot. On my old DD setup I use about 300watt/hours to get to work and about 260 to get home, its 13.3 miles each way. I ride to work and lock up my bike, I open the case side and take all the cells out, I carry them upstairs to my office and charge them up. I use a lipo charger that (I think if I remember right) can do 8 series max, 7 amps. I power it with two old laptop power supplies and I can run it about 5.5 amps charging current based off the laptop supply limits. I usually charge them on balance setting at the office.
I use panniers to carry my lunch/clothes and the charger and laptop supplies for it.

When I am done for the day I carry the cells downstairs, put them back in and wire them up, and ride home. When I get home the bike goes in my workshop so I can either pull the cells out and balance charge them again or leave them in and just do a normal charge.

This is all a bit of a pain because of the following reasons:

1) I have to take all the cells out of the bike at work everytime. I can't bring the bike into work.
2) I have to take care when I'm at work charging, because if there was a problem with the packs I might smoke out the office. I feel better if I can always keep an eye on them, this is inconvenient. I also have to do them one at a time, so I have to switch packs 4 times.
3) At home I also don't trust leaving the batteries charging so I keep an eye on them a lot. I also have to switch 4 times between each pack.
4) I only have one charger so I have to carry it everwhere.

So do folks have any advice? I think you can buy 12s chargers now which might help? or buy a different battery or something? I'm open to help to simplify by ebike riding commute!!

Thanks![/img][/img]

 

[Ykick]

That does sound like a lot of trouble. Can you double your pack capacity to 8 bricks and still fit inside your enclosure? If so, you could serial bulk charge only at home. That's what I do but my commute is 4 miles each way.

 

[bart_dood]

That does sound like a lot of trouble. Can you double your pack capacity to 8 bricks and still fit inside your enclosure? If so, you could serial bulk charge only at home. That's what I do but my commute is 4 miles each way.

I don't think I have enough space inside the case for that. I thought about buying one of those headway 10ah kits on ebay and fitting the box with the headways permanently, then moving the lipo packs outside somehow. I would wire them in parallel and I could ride both ways on one charge and skip the re-charge at work.
I'd still have some hassle at home charging up, but at least it would be once a day and not twice a day.

My geared motor which is lower power seems to have dropped my power per mile usage, it used to be around 22wh/mile but now seems to be 16-17wh/mile. Which means I don't need a whole lot of extra battery capacity to be able to do work and back on a single charge.

 

[Ykick]

Maybe 3P would fit? At those Wh/mi 15Ah should be okay for a while or until cold weather.

 

[bart_dood]

Maybe 3P would fit? At those Wh/mi 15Ah should be okay for a while or until cold weather.

That might work, could be a real squeeze but I'll measure up when I get home and see.

 

[dogman dan]

Best Idea I can think of is two batteries. You could rig a backpack battery to carry the second pack if nothing better works. But maybe you can cram in 8ah of additional capacity if 5 ah more is not enough.


Or a 48v 15 ah ping, with just about 700wh. If there is a plug you can park the bike near, a 10 ah ping would work, since you could charge it right on the bike. Or charge in the office with a LOT less worry.

Never heard of paralelling 4 packs to charge them all at the same time?

 

[bart_dood]

Best Idea I can think of is two batteries. You could rig a backpack battery to carry the second pack if nothing better works. But maybe you can cram in 8ah of additional capacity if 5 ah more is not enough.


Or a 48v 15 ah ping, with just about 700wh. If there is a plug you can park the bike near, a 10 ah ping would work, since you could charge it right on the bike. Or charge in the office with a LOT less worry.

Never heard of paralelling 4 packs to charge them all at the same time?

Your last question I haven't tried this, would this be balanced or just regular charging?

My other question is are there any boards or electronics to allow me to not have to plug/unplug things when I'm using or charging the batteries? I guess I could just buy 10ah batteries then there would simply be 12 in series allowing me to use a 12s charger...

 

[melodious]

Besides adding more batteries, how about using your bike in the meantime and start on another bike build. Your experience and wisdom in hand you now know or are familiar with making the charge process simpler. I'm not sure with the amount of daily commute miles you put on it, but it sounds as if we're forced to think outside the frame now.

Looking at your battery compartment, it looks pretty slim (which is nice). What about making another compartment, only wider. That way your battery options open up.

 

[dogman dan]

Good thinking Melodious. The same covers could easily cover a wider box, 2 bricks of lipo wide.

If you paralell just the big wires you can do a non balance charge. To do a balance charge, you need to also add a harness to paralell the balance plugs as well.

Obviously there is no need whatsoever to balance charge at work. Balance only when you need to. .01v different is not out of balance enough to care about.

One device for paralelling http://epbuddy.com/index.php?main_page=index&cPath=15

Other options. This stuff you can make yourself, using wires and plugs. The Just paralell adapters are easy to make by splicing together some Jst extensions. http://epbuddy.com/index.php?main_page=index&cPath=26_14

 

[bart_dood]

Besides adding more batteries, how about using your bike in the meantime and start on another bike build. Your experience and wisdom in hand you now know or are familiar with making the charge process simpler. I'm not sure with the amount of daily commute miles you put on it, but it sounds as if we're forced to think outside the frame now.

Looking at your battery compartment, it looks pretty slim (which is nice). What about making another compartment, only wider. That way your battery options open up.

Hi,

Thats a pretty good idea, I don't think I want to start with another bike. I'd rather tweak this one. I already have 6 bicycles in my workshop and I'm out of space! also I bought this particular bike just for E commuting on, and I customized it to be really comfortable for distance riding.

If I made the compartment wider it might make pedaling the bike a little more tricky, I'll have to go home and sit on it and see if I can get away with something wider between my legs, perhaps I could widen in in some areas to fit more batteries in.
I use the bike on and off to commute, I've put about 1300 miles on it to work so far. I plan on using it a lot more this year as soon as the darn rain goes away

 

[bart_dood]

Good thinking Melodious. The same covers could easily cover a wider box, 2 bricks of lipo wide.

If you paralell just the big wires you can do a non balance charge. To do a balance charge, you need to also add a harness to paralell the balance plugs as well.

Obviously there is no need whatsoever to balance charge at work. Balance only when you need to. .01v different is not out of balance enough to care about.

One device for paralelling http://epbuddy.com/index.php?main_page=index&cPath=15

Other options. This stuff you can make yourself, using wires and plugs. The Just paralell adapters are easy to make by splicing together some Jst extensions. http://epbuddy.com/index.php?main_page=index&cPath=26_14

The box is kind of molded fiberglass, it is basically all one piece with a wooden door which is offset inwards from the edges. Its not easy to modify, but if I thought it was worth it I could do that.
Some of my cells aren't really well balanced, I get perhaps 0.08v or more difference, which is why I tend to balance them quite often. They were quite cheap but I'd like to get my money's worth out of them before replacing them.

Thanks for the links I'll check them out!

 

[motomech]

Hyperion 1420I is what you need

There are some nice 12S one-plug charge/balance solutions in this thread,

http://endless-sphere.com/forums/viewtopic.php?f=14&t=23362

 

[bart_dood]

Hyperion 1420I is what you need

There are some nice 12S one-plug charge/balance solutions in this thread,

http://endless-sphere.com/forums/viewtopic.php?f=14&t=23362

Yeah I'm leaning towards buying a pair of extra 6s 5ah lipo's and putting them in my panniers with wiring and a plug/socket to connect them to the main housing on my bike. This will give me 48v 15ah which is enough to ride to work and back on one charge.
Then when I get home I will use a new 12s charger (like the one above) and charge the 3 sets of in series cells one at a time, balanced as well.

This means I should be able to always keep the main set of packs in the bike housing basically all the time..hmmm actually if I could leave them in permanently then I could try and cramp in two more packs and I wouldn't need the pannier space...

I need to go home and measure stuff, maybe order two more packs and see if I can squeeze them in....

Thanks everyone, its all great info!

 

[motomech]

QUOTE -"Then when I get home I will use a new 12s charger (like the one above) and charge the 3 sets of in series cells one at a time, balanced as well." _END OF QUOTE

Actually, the cool thing about the Hyperion 1420i is that you can balance charge 12S/3P without dis-connecting anything.

El steak did it this way[page 3]

 

[MadRhino]

Spare a power bulk charger at work.
15 minutes of careful monitoring, you're done and can work in peace

 

[bart_dood]

QUOTE -"Then when I get home I will use a new 12s charger (like the one above) and charge the 3 sets of in series cells one at a time, balanced as well." _END OF QUOTE

Actually, the cool thing about the Hyperion 1420i is that you can balance charge 12S/3P without dis-connecting anything.

El steak did it this way[page 3]

So its ok to put all the balancing connectors on the 3P together? so essentially making all the packs in parallel and 3 series? If I could wire all this into my battery box it would be awesome, one plug in and balance/charge in a single operation...

 

[bart_dood]

Hi folks,

So I figured out I could buy two more 6s 5ah zippy packs and fit them in my housing, making a 48v 15ah pack in total, enough to ride to work and back on a single charge.
I then bought a hyperion 14s charger and 3 dell 19.5v 6.7A laptop power supplies to power it with, I'm making wiring harnesses using a D sub plug for the balancing, so all I do when I get home is plug two plugs in and balance and charge. Simple

Here's a photo of the 6 zippy packs in my housing, I need to make a new door to make it all work but thats ok.