Joff
Posts: 47
Joined: Wed Jan 02, 2019 2:44 am

Re: Parallel HV Battery for added range.

Sat Mar 21, 2020 11:26 am

I forgot to answer all your questions Art. This 8Ah aux battery is just 40 pounds. temporary plywood frame that keeps the cell packets squoze the way they like. I just have it sitting behind the rear seats, it cant go far. No BMS for balancing for now. If I were to cycle this pack a lot, it would be worth adding a bms system, but I will be switching to other batteries if all goes well. Running parallel with the i3's batteries will keep them far from being overcharged or undercharged unless they got way out of balance.

Joff
Posts: 47
Joined: Wed Jan 02, 2019 2:44 am

Re: Parallel HV Battery for added range.

Mon Mar 23, 2020 3:15 pm

Let me know if the link works please! This is the temporary battery that I am already done with https://photos.app.goo.gl/pbChZTe9JR4oZ8xf9

Joff
Posts: 47
Joined: Wed Jan 02, 2019 2:44 am

Re: Parallel HV Battery for added range.

Mon Mar 23, 2020 3:31 pm

I typically can get 10 more miles range than it thinks I can. with a small auxiliary, it's hard to know how much of the range is due to frugal driving and how much is the weather and battery. It took me several days to use it up, doing mainly city driving. In fact, I gave up before running the battery completely out. https://photos.app.goo.gl/2E6hckb9L8gtmBeA7
I will know for sure on the next battery. I bought a full set of 6 battery modules from an i8. The cells within each pack are perfctly balenced but the packs are at different states of charge. I've temporarily wired them in parallel while I charge them with an electric unicycle charger https://photos.app.goo.gl/jt6sujSEgA2exe8V9

alohart
Posts: 1982
Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: Parallel HV Battery for added range.

Mon Mar 23, 2020 5:28 pm

Joff wrote:
Mon Mar 23, 2020 3:15 pm
Let me know if the link works please!
Photos are viewable, thanks!
Aloha,
Art

2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE

eNate
Posts: 373
Joined: Mon Sep 09, 2019 5:33 pm

Re: Parallel HV Battery for added range.

Mon Mar 23, 2020 5:47 pm

Joff wrote:
Mon Mar 23, 2020 3:15 pm
Let me know if the link works please! This is the temporary battery that I am already done with https://photos.app.goo.gl/pbChZTe9JR4oZ8xf9
Hey! Once you get this sorted I know just the place in your BEV to stash it!

Image
2 0 1 7   B M W   i 3   9 4 A h   B E V  O a k l a n d
 Wokeby Trunk Extension | Duosida 16A L1 EVSE
 SeaSucker Monkey Bar Roof Rack

3pete
Posts: 47
Joined: Tue Mar 19, 2019 9:03 pm

Re: Parallel HV Battery for added range.

Tue Mar 24, 2020 4:05 pm

Cool stuff! And as a 2014 BEV owner, it'd be pretty neat to be able to take advantage of that empty rex-house in the back for a little more all-electric range!

Joff
Posts: 47
Joined: Wed Jan 02, 2019 2:44 am

Re: Parallel HV Battery for added range.

Wed Mar 25, 2020 6:04 pm

Yes, there is a ton, er, many a cubic foot of unused space! For now I would like to be able to toss it out of the car if it burst into flames, but the longer i play with it the safer it seems. I have not decided if I want to put some of them where the rex would have gone or put them all back further between the motor area an the rear bumper. I could spread them out and keep them all low, or if it is mainly for winter range extention, mayby rear most is the best for winter rear wheel traction. I was concerned that having the modules at different temperatures would cause the voltages to change but they remained the same with a 20f degree difference. I 8 modules I will be using are 27 lbs each so 162 pounds plus what I contain them in. 9kwh all together. Can anyone recommend a source of info on ISTA ? Can it help me tell my car I have more kwh than it previously knew about?

Joff
Posts: 47
Joined: Wed Jan 02, 2019 2:44 am

Re: Parallel HV Battery for added range.

Thu Mar 26, 2020 7:44 am

I have the I8 modules ready to test, but no where I need to drive, with the covid 19 shelter in place/ quarantine situation. I'm looking into what to do about the bms. i don't want to spend $1200 on a orion system that can handle 96s. As long as I can keep all the cells balanced, I don't need to worry about over voltage or under voltage. I was considering using 6, 60amp 16s bms from aliexpress that are about $30 each i8 module would have it's own. the module would still have to be balanced against each other once in a while. Then I saw somewhere that 16s active battery balancer (not a full battery protection bms) can be wired to another, cascade fashion to cover 32 cells. Maybe I can balance all 96 cell with 6 of them. Can't find info on that. Not even sure what that is called. Here are the balencers I am looking at. https://www.aliexpress.com/item/3296796 ... 2ylgT&mp=1

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