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Plug Bug: DC-DC Converters


I’m ditching my IOTA DLS-55 DC-DC converter. The inrush limiter I use (which replaced the AC bridge rectifier) eventually dries out and cracks, and then stops working. I got ~1000 miles on my last modification (I’m at ~1700 miles right now).

So, I’m doing research on what is out there to hopefully make the right choice. I’m only listing ones that I could actually use (ie: rated > 25amps, ideally higher, and have an input voltage appropriate for my pack at 154v nominal).

Belktronix – $300
675W ( up to 55 amps) 120V-350V (based on application)
Great support from the owner/creator – Bryan.
http://www.belktronix.com/isodcdc.html
http://www.belktronix.com/pricing.html

Cloud Electric generic brand. $280
Probably the same as the Kelly, but has a bit higher output, which I like.
132-168V nominal input 13.6V / 35A out (sealed type)
http://www.cloudelectric.com/category_s/8344.htm
Which are these ones imported from China: http://www.hztiecheng.com/english/ specifically: http://www.hztiecheng.com/english/Product/T16/38.html

Others that might meet my needs, but have concerns:

Vicor: 150V Input Maxi Family DC-DC Converter – $280′ish
But, these are just the bricks and not a complete system! Vicor produces high quality parts, from what I hear
http://cdn.vicorpower.com/documents/datasheets/ds_150vin-maxi-family.pdf
http://vdac.vicorpower.com/vdac/predefined/00predef-mods.asp

Kelly HWZ Series DC/DC Converter 156V to 13.5V 25A – $150
I’ve heard from two sources that Kellys are bad. Another source (Travis) has had good success with them.
http://kellycontroller.com/hwz-series-dcdc-converter-156v-to-135v-25a-p-536.html

Zivan – $498 – $525
14vdc / 60 amps output. I’m not so sure about the Zivan, since they seem to be more of an AC-DC charger, than a purely designed DC-DC converter. It looks like they come with an AC plug, which I don’t want. I want something designed for a car.
http://store.kta-ev.com/zivandc-dcconv100-200vinp.aspx
http://www.evolveelectrics.com/DC-DC%20Converters.html#elcondcdc

Elcon – $250, 25amps out
These seem to be the same one as the generic Cloud Electric ones, just rebranded. The pictures and part numbers are identical.
http://www.evolveelectrics.com/DC-DC%20Converters.html


So, I’m opting for the Belktronix — it gives the most output (35 amps) with no fans, and higher output if you cool it (up to 55amps). Plus, Bryan is quick to answer emails and seems to really support his products. Unfortunately, it has a 3-4 week lead time, and right now I’m using my car with the temporary fix again (another inrush limiter) which could fail at anytime.

How much would it cost me to drive a gas car for 4 weeks, assuming I can charge at work for free? I drive 40 miles/day on normal, and 50 miles when I got to the gym (twice a week). 40*3 + 50*2 = 120 +100 = 220 miles / week for 4 weeks gives: 880 miles. Say I drive the old Ford Focus we have, ~30mpg: 880/30 = ~29.3 gallons of gas. Times $4/gallon (which it basically is here in CA): $117. It would be worth it that much for me to get the converter earlier to avoid using the gas car. (NOTE: Edited my math).



7 Responses to “Plug Bug: DC-DC Converters”

  1. DAVinThePI says:

    “How much would it cost me to drive a gas car for 4 weeks, assuming I can charge at work for free? I drive 40 miles/day on normal, and 50 miles when I got to the gym (twice a week). 40*3 + 50*2 = 120 +100 = 320 miles / week for 4 weeks gives: 1280 miles. Say I drive the old Ford Focus we have, ~30mpg: 1280/30 = ~43 gallons of gas. Times $4/gallon (which it basically is here in CA): $172. It would be worth it that much for me to get the converter earlier to avoid using the gas car.”

    Hate to be a math geek, but wouldn’t that be 120 + 100 = 220 miles/week? That times 4 weeks = 880 miles. Your Focus would consume 880/30 = ~29.33 gallons of gas. Times your $4/gallon CA gasoline (wish I could get it that cheap) $117. It would still be worth it.

    A more geeky solution would show your 220 miles/week * 4.35 = 956.6 miles/month. That figure divided by your Focus mileage figure would be = ~31.9 gallons @ $4/gal would still work out to $127.55, which again validates your decision.

    I have a small lightweight double cab pickup, made here in the Philippines I’m considering converting to electric, but that’s all I’ve done so far… considered it. It would be expensive for me in light of the original investment (new price less than $5,000), but would still make an interesting project.

  2. corbin says:

    hah, whoops! Yeah, that’s what I get for quickly adding stuff in my head…

  3. Travdude says:

    I do the same geeky math with my truck, it costs me $15 to drive to work and back.

    You made a good choice, Bryan does give good support and the power output of his unit is worth the extra price.

  4. Wayne Bennion says:

    Hi!
    Wasn’t sure where to leave this… I’m a new electric Bug owner. I bought an almost-converted ’73 Super Beetle from Bill Warner in Ceres. Now it sits in Castro Valley. I think I blew the Curtis controller on the first time coming up my hill last week.

    Your workshop is impressive! Wow! I expect I’ll be begging advice from you when I get things settled down enough to think clearly (if that ever happens!).

    Right now I’m looking at batteries. I want to do lithium, and Winston/Thundersky is offering them for $1.20/ah. Bill tells me the ni-cad batteries in it now are too weak and are bad for the controller. The thundersky are lots lighter and space-efficient, but do I really want to spend 150% of the purchase price on batteries?

    I’m glad to see such a beautiful Bug in the area.

  5. corbin says:

    Update: I have ~8600 miles or so now. The Belktronics DC-DC converter has been a GREAT choice.

  6. corbin says:

    Update: 15,000 miles on he car. The Belktronics still rocks.

  7. Jay Donnaway says:

    Wayne, there’s not many of us running nicads, but there may be a more life in ‘em than you think.
    http://www.karmanneclectric.blogspot.com/2012/03/more-things-change-more-they-stay-same.html
    Drop me a line and/or join the bb600 list on yahoogroups for more nicad info.
    If you did ditch the nicads and need a home for ‘em, I’m interested!
    Cheers
    Jay
    jray3 at aol dot com

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