Souping up the Sierra, Li Ion style

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LCoolio

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Hey all,

I recently got my hands on a DiveX Sierra with a dying NiMH battery, and its time to make the switch. I'll be using a Smart DPV controller. I have a few options, and I'm hoping for some advice from those with more experience with electrical systems than Grade 12 Physics. I've reached out to some local battery vendors, but in the mean time I'm looking for COTS setups. 2 of my options would have me putting 2 36V ~10ah packs in parallel, vice the one 36v 20ah option or 36V 15ah Ping LIFePo4. If I was to put the 2 packs in parallel, would that be a simple function of soldering two leads into one, or would I run into battery management issues. Both small packs have less than 30A continuous current, but in parallel their current would be additive, correct?

36V 37V 42V 10.2Ah 20A 10200mAh Lithium Li-ion Battery Pack [36V 10.2Ah 20A Battery BL-10S3P] - $209.00 : Lithium Rechargeable Batteries, Battery BMS, Pack Assembling
Custom Li-Ion 26650 Battery: 36V 20Ah (720Wh, 50A rate, 5x8, INR-26650-5000)
Bare battery 12.8Ah - EbikeBC | Canada's Best EBike and Conversion Kit Store

Understanding that I like tinkering and am willing to and have access to the tooling required, let me know what you all think.

Cheers
 

rjack321

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I don't like any li-ion battery made with "high quality" cells. If they dont tell you the actual brand, model, and capacity then they are just blowing smoke. Especially a mystery foreign assembly place.

The batteryspace packs are legit just expensive. And you can build your own for about half the price. You will pay through the nose getting it from Cali to BC.

Try Charlene Barker in Alberta (the name of her shop escapes me), she can get you a drop-in Sierra replacement.

Edit: she is a dealer for replacement batteries in CDN
Aqua Sport Online – Aqua Sport Scuba Center
 
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LCoolio

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My Sierra is definately a 24v pack, not 36v.

The upgraded electronics, either from DiveX or Smart DPV, use 36v. Although the Smart DPV can still use 24v.

While the Cellpower options are good, I'm trying to find a balance between a bit less capacity and price. But ultimately, I can't go wrong with it.
 

Jack Hammer

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The upgraded electronics, either from DiveX or Smart DPV, use 36v. Although the Smart DPV can still use 24v.

While the Cellpower options are good, I'm trying to find a balance between a bit less capacity and price. But ultimately, I can't go wrong with it.
Got it. :)

I've got an older early model Sierra. The electronics are only upgradeable by replacing everything. It came with a slightly lower wattage motor and non programmable electronics.
 

rjack321

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The upgraded electronics, either from DiveX or Smart DPV, use 36v. Although the Smart DPV can still use 24v.

While the Cellpower options are good, I'm trying to find a balance between a bit less capacity and price. But ultimately, I can't go wrong with it.

You can build your own in the 22-24Ah range for about $500. (stock NIMH is 15ah) A 7s7p or 7s8p would avoid spending $350 to replace the electronics.
 
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LCoolio

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You can build your own in the 22-24Ah range for about $500. (stock NIMH is 15ah) A 7s7p or 7s8p would avoid spending $350 to replace the electronics.

In terms of actual burn time, is ah or wh a better indication?
 

rjack321

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In terms of actual burn time, is ah or wh a better indication?
Ah is rather meaningless as the actual energy inside is entirely dependent on what voltage you are talking about. So its not a good way to compare batteries (or scooters) which are running at different voltages.

Wh is independent of voltage as its A x V x time = Wh
 
https://www.shearwater.com/products/swift/

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