Author Topic: Battery Upgrade?  (Read 1232 times)

FreepZ

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Battery Upgrade?
« on: November 22, 2011, 02:10:39 PM »
A while ago, I tried to replace the battery of my old Black and Decker weed whacker. I figured that since it was a fairly old machine, battery technology should have marched on and I would be able to get a new battery that was lighter or longer lasting that the old one. Sadly, the replacement was pretty much exactly the same as the old one, and would cost about half the price of a new weed whacker. I ended up tossing the weed whacker and using an even older machine that plugged into the mains.

On the other hand, I saw a video of the White Zombie Electric Drag Racing car getting a battery upgrade. The owner replaced his lead acid pack with a lithium pack. The battery swap was pretty straightforward - the only issue being that the new pack wasn't the same dimensions as the old one, so they had to get creative to fit it into the car.

In theory, I should be able to buy my Empulse with the 10 kWh pack when it comes out, and when a better battery shows up, I should be able to sell the old one and install the new pack, and like magic, I have more battery!

Given my experience with the weed whacker, I doubt that life is going to be that simple.

  • Do you think it could to be that easy?
  • Is there much difference between the various battery capacities? I mean besides having more or less batteries in the "tank", how much does the rest of the bike change?
  • Perhaps the essence of my question is: how easy would it be to scale up the Empulse's battery setup?

My pessimistic side leads me to believe that no upgrade will be possible (without some serious (or expensive) work). What do you think?
Richard #935 #595 #44

Gavin

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Re: Battery Upgrade?
« Reply #1 on: November 22, 2011, 02:57:20 PM »
In theory...easy...in practice...mmmm


Notice that the 2009-2011 Enertia can not get the batteries from the Plus...

I think the issue tends to be the Battery Management Unit...Now if you can replace that with the new batteries, or somehow update the BMU software, then it actually should be easy...

Gavin


edit...ps...protomech will show up soon and give a much much better and more detailed answer....my new motto is: What Would Proto Write (WWPW)...I wish I knew a fraction about EVs and batteries that he does
« Last Edit: November 22, 2011, 03:35:35 PM by Gavin »

protomech

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Re: Battery Upgrade?
« Reply #2 on: November 22, 2011, 04:10:12 PM »
Depends. Brammo hasn't made any hard commitments, but they've indicated that they'd like to make battery upgrades a possibility. A drop-in replacement would be fantastic; but keep in mind that the batteries will be expensive and heavy.

Here are a couple more examples:

Zero sells an adapter to allow the 2010 X and MX bikes to use the 2011 pack. They don't have an adapter for the S and DS bikes which use fixed battery packs and would require substantially more disassembly, nor do they have an adapter for the 2012 packs (which are about 50% higher capacity).

A third party sells an 8.0 Ah pack as an upgrade for the 2000-2006 Honda Insights and Civic Hybrids. Insight uses a 144V 6.5Ah pack (at least until 2005), Civic Hybrid uses a 6.0 Ah pack. Capacity isn't a huge concern for a hybrid, but the new packs supposedly can put out a little more power, tolerate a little higher charge rate, and run a little cooler. Cost is a bit higher for the new pack ($1800 + shipping) than a refurbished pack ($1000 + shipping).


Historically, battery technology has improved slowly enough that an upgrade may be pretty minimal. In the case of the Insight, the new packs are 25-30% higher capacity and power from the original packs 10 years ago. It's pretty attractive if you are replacing the old pack anyhow - but maybe not something you would pay to upgrade early.

Additionally, most battery-powered electronic equipment is pretty well outdated by the time significant battery improvements have been made, reducing the payback on designing an upgraded drop-in pack. This will probably change as we use packs for transport - a ten year old car may be a little rough on the interior and exterior, but generally an electric powertrain will still be working well.

The big battery increases we've seen recently (Enertia 3.1 kwh to Enertia Plus, Empulse 6.0 - 10.0 kwh, 2011 Zero to 2012 Zero) have been chemistry changes. Swapping in a different chemistry has the potential for larger gains than just swapping in an upgraded version of the same chemistry (lithium to nimh vs nimh to nimh). They may also be more complicated; may need a different battery management system or onboard charger; may need active cooling or venting or other airflow considerations; the new batteries may be packaged in a way that can't be made compatible with the old bike.

Still an option for the hobbyist to design a replacement pack. I'll be interested to see what people do with the original Enertias in 5-10 years when the battery packs are being replaced.
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protomech

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Re: Battery Upgrade?
« Reply #3 on: November 22, 2011, 05:50:13 PM »
Here's an example candidate pack for the Enertia 3.1 kwh.

GBS LiFeMnPO4 12.8V 40 Ah packs, need six to replace the six Valence 12.8V 40 Ah packs in the Enertia. These are very close to drop-in replacements except for maybe battery communications.

http://elitepowersolutions.com/products/product_info.php?cPath=25&products_id=90
* 2nd gen packs are 78 wh/kg, 109 wh/L, $480/kwh.
* No weight change vs the Valence packs. 3.1 kwh pack = $1488, same weight = 40 kg.
* Replacement 3.1 kwh pack cost = $1488.
* pack size is 208x125X180mm vs Valence 197x131x182mm - hopefully would fit in the Enertia frame.

http://elitepowersolutions.com/products/product_info.php?cPath=25&products_id=149
* 3rd gen packs are 103 wh/kg, 139 wh/L, $580/kwh.
* Only available in 200 Ah (!) packs for now.
* 40 Ah packs would be a bit smaller. 3.1 kwh pack = ~$1800, 30 kg (-10 kg over stock 3.1).
* 60 Ah packs would be a big larger (+17%). Packaging might be a problem. 4.6 kwh pack = ~$2400, 45kg (+5 kg over stock 3.1).

30% more energy per weight, 28% more energy per volume. Not bad for a battery upgrade two years later on the same chemistry.


The Enertia Plus pack is a different chemistry, higher capacity, lower weight. But the GBS batteries should be easier to drop into the original Enertia .. and the longer you wait, the better batteries will be available.
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WanderLust

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Re: Battery Upgrade?
« Reply #4 on: November 23, 2011, 12:38:45 AM »
The Enertia Plus pack is a different chemistry, higher capacity, lower weight. But the GBS batteries should be easier to drop into the original Enertia .. and the longer you wait, the better batteries will be available.

Seems to be the case with most consumer electronics... Electric bikes seem to be falling into that category...
But here's the thing. Depending on your commute, you might not even hit 2K charge cycles in 5 years...
5 years from now, there will probably be a lot better batteries out there, but the Empulse 10 for example may only have deteriorated to 80% of it's original capacity... would it even be worth it to upgrade it to a new battery?
In my case probably not... But then again, situations change, who's to say needs won't change in 5 years, or that I'll even be riding in 5 years? (I hope to god that doesn't happen)

2Slow4u

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Re: Battery Upgrade?
« Reply #5 on: November 29, 2011, 07:20:38 PM »
I dont see your average garage tinkerer putting together an upgraded pack in 5-10 years to be honest. There may be some aftermarket companies that sell and upgrade kit though. There is a whole list on things to take into consideration including electrical, mechanical, thermal, system integration, safety, reliability, support and cost and quite frankly its not an easy l combination. If someone does come up with a drop in upgrade thats affordable, bravo. But i dont see it happening financially.

860

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Re: Battery Upgrade?
« Reply #6 on: November 30, 2011, 01:11:09 AM »
...the replacement was pretty much exactly the same as the old one, and would cost about half the price of a new weed whacker. I ended up tossing the weed whacker....

Classic case of planned obsolescence.  The problem with your wacker is that Black and Decker doesn't want you to buy a new battery.  They want you to buy a completely new wacker.  And since there is no aftermarket for wacker batteries, they won. 

Hopefully Brammo will be better than that. 

protomech

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Re: Battery Upgrade?
« Reply #7 on: November 30, 2011, 01:27:38 AM »
EV battery packs, especially lithium-based packs, are still too young to really say what a ten-year-old pack will look like.

There's still a pretty active user community behind Toyota's RAV4 EV, which was released in the early 00's and used a 27 kwh nimh pack. User reports that I've read (not a fair sample) seem to be mixed on whether they have replaced the pack or are still running along with most of the original range remaining. Pack replacements seem to be more due to pack failures than decreased range.
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