Re: [EVDL] Q about using an electronic load.

2014-11-08 Thread Zeke Yewdall via EV
Well, there are grid-tie inverters down as small as 200W or so readily available, often down to 12v input. Yes, though the two I have (Trace Microsine and Enphase) won't work with a battery or DC supply as their input. As Lee said, just about all grid-tied microinverters are designed

Re: [EVDL] Q about using an electronic load.

2014-11-07 Thread Lee Hart via EV
Roger has some excellent advice here. It reflects a lot of what I do myself. :-) Roger Stockton via EV wrote: Thought I'd mention that while a programmable load is an *excellent* way to discharge when testing batteries, it can be pricey... Indeed. Programmable loads get very expensive if you

Re: [EVDL] Q about using an electronic load.

2014-11-07 Thread Michael Ross via EV
Thank you , Lee. Some concerns about cost may drop away because I am not aiming at automotive EVs - for now , maybe never. Because I need to go for some grant funding, I have to be aimed at manufacturers - job creation is what everything is about these days (I don't disagree). The automotive

Re: [EVDL] Q about using an electronic load.

2014-11-07 Thread Peter Gabrielsson via EV
One relatively cheap way of doing high power cycle testing is to cycle power between a large battery bank and the test battery using a bidirectional DCDC converter. The DCDC is simple since it's just a switching pole with an inductor and some controls. A DC motor controller with regen capability

Re: [EVDL] Q about using an electronic load.

2014-11-07 Thread Lee Hart via EV
Peter Gabrielsson via EV wrote: One relatively cheap way of doing high power cycle testing is to cycle power between a large battery bank and the test battery using a bidirectional DCDC converter. The DCDC is simple since it's just a switching pole with an inductor and some controls. A DC motor

Re: [EVDL] Q about using an electronic load.

2014-11-07 Thread Roger Stockton via EV
Michael Ross wrote: I think I need to be a notch or two above garage testing.  To provide results worth referencing.  I do have to be frugal and not spend where good things can be fabricated.  We want to be cost effective for clients that aren't at the million$ a year in sales level. Thanks

Re: [EVDL] Q about using an electronic load.

2014-11-07 Thread John Lussmyer via EV
On Fri Nov 07 16:07:19 PST 2014 ev@lists.evdl.org said: If you are able to consider sufficiently large electronic loads, then ones that can push the energy back into the grid rather than dissipating it as heat become an option. This capability doesn?t really become available until you are

Re: [EVDL] Q about using an electronic load.

2014-11-07 Thread Roger Stockton via EV
John Lussmyer wrote: If you are able to consider sufficiently large electronic loads, then ones that can push the energy back into the grid rather than dissipating it as heat become an option. This capability doesn?t really become available until you are looking at loads of at least 6kW, and

Re: [EVDL] Q about using an electronic load.

2014-11-07 Thread Michael Ross via EV
Hi Roger, Just to clarify...this is not a personal project (though I do take it personally), but it is also not commercial - in the profit taking sense. The NC Clean Energy Technology Center is a not for profit (in fact the lab barely survives on fee for service work, grants, and some small

Re: [EVDL] Q about using an electronic load.

2014-11-06 Thread Roger Stockton via EV
Michael Ross wrote: If I have a programmable electronic load, rather than purely resistive loads, is this an unrealistic way to discharge batteries? I gather they use power MOSFETS and switch them to product the desired output current from the batteries. I think this implies some

Re: [EVDL] Q about using an electronic load.

2014-11-06 Thread Cor van de Water via EV
: cor_van_de_water Tel: +1 408 383 7626 -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Roger Stockton via EV Sent: Thursday, November 06, 2014 1:12 PM To: Electric Vehicle Discussion List Subject: Re: [EVDL] Q about using an electronic load. Michael Ross wrote: If I have

Re: [EVDL] Q about using an electronic load.

2014-11-06 Thread Michael Ross via EV
List Subject: Re: [EVDL] Q about using an electronic load. Michael Ross wrote: If I have a programmable electronic load, rather than purely resistive loads, is this an unrealistic way to discharge batteries? I gather they use power MOSFETS and switch them to product the desired output

Re: [EVDL] Q about using an electronic load.

2014-11-06 Thread Cor van de Water via EV
From: Michael Ross [mailto:michael.e.r...@gmail.com] Sent: Thursday, November 06, 2014 2:25 PM To: Cor van de Water; Electric Vehicle Discussion List Subject: Re: [EVDL] Q about using an electronic load. I have heard of putting a roll of fencing in a tank to steam off heat

Re: [EVDL] Q about using an electronic load.

2014-11-06 Thread Lee Hart via EV
Roger Stockton via EV wrote: A programmable load is fine for discharging batteries. I believe the power devices are operated in linear mode, not PWMed, and have not observed any transients on the load current on any of the electronic loads I've used. I agree. The programmable loads I've

Re: [EVDL] Q about using an electronic load.

2014-11-06 Thread Lee Hart via EV
Michael Ross via EV wrote: I have heard of putting a roll of fencing in a tank to steam off heat. Is this useful with a programmable load? Or is this just a crude way to discharge. This is just a quick-n-dirty way to make a big, high-power, cheap resistor. Any recommendation of actual

Re: [EVDL] Q about using an electronic load.

2014-11-06 Thread Michael Ross via EV
, 2014 2:25 PM To: Cor van de Water; Electric Vehicle Discussion List Subject: Re: [EVDL] Q about using an electronic load. I have heard of putting a roll of fencing in a tank to steam off heat. Is this useful with a programmable load? Or is this just a crude way to discharge. Someone

Re: [EVDL] Q about using an electronic load.

2014-11-06 Thread Paul Dove via EV
I have always used a load bank. It works great Sent from my iPhone On Nov 6, 2014, at 2:18 PM, Michael Ross via EV ev@lists.evdl.org wrote: I am investigating how to test cells and packs - I will need to charge and discharge. If I have a programmable electronic load, rather than purely

Re: [EVDL] Q about using an electronic load.

2014-11-06 Thread Paul Dove via EV
- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Roger Stockton via EV Sent: Thursday, November 06, 2014 1:12 PM To: Electric Vehicle Discussion List Subject: Re: [EVDL] Q about using an electronic load. Michael Ross wrote: If I have a programmable electronic load, rather than

Re: [EVDL] Q about using an electronic load.

2014-11-06 Thread EVDL Administrator via EV
My dummy load is the resistive heat strips from a couple of derelict heat pumps. Since I use them at 144v rather than 240v, I split each in the middle. With all 4 (mismatched) half-elements in parallel, it uses about 100 amps at 144 volts, exactly what I was looking for. It also heats up the

Re: [EVDL] Q about using an electronic load.

2014-11-06 Thread Roger Stockton via EV
Michael Ross wrote: I have heard of putting a roll of fencing in a tank to steam off heat. Is this useful with a programmable load? Or is this just a crude way to discharge. Probably not, unless the electronic load you choose is designed to be used with an external load bank, or you plan

Re: [EVDL] Q about using an electronic load.

2014-11-06 Thread Michael Ross via EV
Excellent, Roger, Thank you. On Thu, Nov 6, 2014 at 7:08 PM, Roger Stockton via EV ev@lists.evdl.org wrote: Michael Ross wrote: I have heard of putting a roll of fencing in a tank to steam off heat. Is this useful with a programmable load? Or is this just a crude way to discharge.

Re: [EVDL] Q about using an electronic load.

2014-11-06 Thread Roger Stockton via EV
Michael Ross wrote: I am investigating how to test cells and packs - I will need to charge and discharge. If I have a programmable electronic load, rather than purely resistive loads, is this an unrealistic way to discharge batteries? Thought I'd mention that while a programmable load is

Re: [EVDL] Q about using an electronic load.

2014-11-06 Thread Michael Ross via EV
Hi Roger, Thanks for the thoughtful reply. I think I need to be a notch or two above garage testing. To provide results worth referencing. I do have to be frugal and not spend where good things can be fabricated. We want to be cost effective for clients that aren't at the million$ a year in