super caps in a NHW10

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antiscab
Senior Member
Posts: 3183
Joined: Mon, 26 Nov 2007, 05:39
Real Name: Matthew Lacey
Location: Perth, WA

super caps in a NHW10

Post by antiscab »

So a recent battery issue in a friends NHW10 had me thinking

The original battery has a voltage range that spans roughly 280v - 380v

144 2.7v 500F caps and balance boards are around AUD$1100 brand new
https://www.aliexpress.com/item/1PCS-AM ... eLevelAB=5

https://www.aliexpress.com/item/1pcs-Fa ... eLevelAB=5

The NHW10 can also charge the HV battery from the 12v battery, for when the caps inevitably go flat (after a couple of days, if not less)

144 x 500F caps gives 3.47F, with a 100V operating window, that gives 347 As (or just shy of 50A for 7 seconds, assuming the little leads don't melt first)

I'm thinking it may be a cheap way to replace the original battery (comparatively speaking). I would only consider this in a hybrid (the caps might only weigh 10kg, but at a cost of $34500/kwh)

Then I realised 400v or 450v caps out of variable frequency drives are a thing. usually high frequency ESR goes up as these things age, but if your discharge time scale is measured in seconds, that's probably not going to matter.
Does anyone know of a stash of caps out of variable frequency drives?
My VLT5042 has 4 x 450v 3300uF caps. I would only need 1000 of them to match the super caps in capacity

I have two NHW10 prius that currently have no battery.
I'm shortly to have 320 x headway 10Ah cells that are a few years old - they will get one of them going (prototype 3 lithium conversion), though I'm tempted to test out the super caps.
I might put a 9 series 500F set (55F) in parrallel with one of the weak cell blocks. 5V operating window at the block level gives 265As
Matt
2023 BYD Atto 3 - 21k km
2017 Renault zoe - 147'000km
2012 Leaf - 101'000km - soon to be trialing a booster battery
2007 Vectrix - 197'000km (retired)
2007 Vectrix - 50k km
Aevzer
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Joined: Wed, 15 Aug 2018, 10:50
Real Name: jon denzer

Re: super caps in a NHW10

Post by Aevzer »

any updates on this?
antiscab
Senior Member
Posts: 3183
Joined: Mon, 26 Nov 2007, 05:39
Real Name: Matthew Lacey
Location: Perth, WA

Re: super caps in a NHW10

Post by antiscab »

The caps I bought didn't meet spec, 300F instead of 500F, with wide variation and really high internal resistance.

I could retry with larger maxwells, but it's cost prohibitive
Matt
2023 BYD Atto 3 - 21k km
2017 Renault zoe - 147'000km
2012 Leaf - 101'000km - soon to be trialing a booster battery
2007 Vectrix - 197'000km (retired)
2007 Vectrix - 50k km
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