OpenEVSE - Open Source Charging Station

[Graycenphil]

Good points. I will move the leads to the protected side; I guess I was following the wiring diagram, which has the protected side on the top, and I moved my turned my fuse block upside down to bring the power in at the top of the box. I guess I was only thinking about the fuses as protection for the big current.

I never thought of the pilot wire thing either, but that will be easy to correct next time I open it up. I guess the reasoning is that when the pilot connection is broken, the relays will shut?

I though of crimping a lug, but figured that might be one more potential spot for resistance. I put the whole wire under one side so that tightening the screw would tend to pull the wire further in.

 

[z0ner]

Remember that the LEAF on-board charger maxes at 6.0kW, so the relay(s) will hold.

I'm going to have to happily retract my statement about the max on the OBC. The MY2013 SV that I picked up recently, manufactured in Dec 2013 charges at 6.56kW (235V*27.9A). I finally decided to meter my OpenEVSE (set to 30A) and with slight fluctuations, that is the charging rate.

 

[QueenBee]

Remember that the LEAF on-board charger maxes at 6.0kW, so the relay(s) will hold.

I'm going to have to happily retract my statement about the max on the OBC. The MY2013 SV that I picked up recently, manufactured in Dec 2013 charges at 6.56kW (235V*27.9A). I finally decided to meter my OpenEVSE (set to 30A) and with slight fluctuations, that is the charging rate.

That makes sense considering the previous 3.3kw charger draws around 3.8kw the difference being from the inefficiency of the charger and overhead of the car being online (pumps, computers, etc).

 

[Graycenphil]

I just got an email from Leviton offering a 10% discount on anything ordered on line. If anybody is buying a J1772 cable and want's the code, let me know.

 

[chris1howell]

Here is the custom Enclosure all finished up...

 

[HighDesertDriver]

Excellent work, Chris. It is amazing, the progressive steps you have taken over the years to arrive at your current configuration(s) and a credit to yourself and those who have encouraged and helped you. Thank you for staying on course and for all your Open EVSE contributions.

 

[EVDRIVER]

So much better than a Juice Box! I'm glad to see you offering quality DIY offerings made with safety in mind not a quick profit.

 

[chris1howell]

Excellent work, Chris. It is amazing, the progressive steps you have taken over the years to arrive at your current configuration(s) and a credit to yourself and those who have encouraged and helped you. Thank you for staying on course and for all your Open EVSE contributions.

So much better than a Juice Box! I'm glad to see you offering quality DIY offerings made with safety in mind not a quick profit.

Thanks guys. I have had a great time and meet some really great people along the way. Many folks have contributed to make OpenEVSE what it is today. Profit was never a goal, in fact I never intended to produce boards at all. I started with 6 for a few MNL friends which turned into another 6 then another... then 25....and 25 more... To date there are over 1000 OpenEVSEs out there and its growing steadily.

I do agree OpenEVSE is significantly better. I feel bad for the folks who paid for a Premium Juicebox 9+ months ago and are still waiting for critical parts to complete their projects and all the Basic builders who ended up as beta testers with hardware revision after revision...

 

[GlennD]

I just ordered a housing to examine and build up a unit. The store said August 10 for delivery. Is this really true?

 

[kubel]

Am I weird for getting all excited over an enclosure? I can't wait to mount this on the side of my house.

 

[GlennD]

The big problem is that Chris posted what looks to be a really nice case as a teaser. He still has to silk screen and paint the rest. Since this is a part time effort that is going to take some time.

 

[chris1howell]

I just ordered a housing to examine and build up a unit. The store said August 10 for delivery. Is this really true?

No, its not true. I screwed up the date.

Should be March 10, they will be ready to ship out on Monday.

 

[GlennD]

Great! I can not wait to see the finished effort.

 

[chris1howell]

Great! I can not wait to see the finished effort.

I just finished the first batch of 10. The clear coat is still to wet to get in the mail today but they will ship Monday as promised. I think they look great...

The next 20 will be ready to pick up from the machinest on Sunday and head to powder coat. And 20 more shipped from the supplier to the machinest.

I am partnering with Tony Williams Quick Charge Power to offer QUALITY cables at a reasonable cost. They will be built up here in the US and crimped to aerospace standards.

Complete kits will be offered very soon with quaility components.

 

[TonyWilliams]

I am partnering with Tony Williams http://www.QuickChargePower.com" onclick="window.open(this.href);return false; to offer QUALITY cables at a reasonable cost. They will be built up here in the US and crimped to aerospace standards.

Complete kits will be offered very soon with quaility components.

Looking forward to it!!! Chris does some great work, so I hope we can keep up!

 

[Devin]

Any possibility of a hydra kit being made available for the electrically nervous of us? Would be nice to replace my 16A and 30A EVSEs with such a device and take better advantage of the 60A service I have coming into my garage for the Focus and the RAV.

 

[greenleaf]

I received the OpenEVSE built by Glenn last Friday. He did a very good job.

I have a question regarding the DelayTimer.

This morning, I tested out the "delay charge" timer. I had set it to start at 22:00 and end at 06:00. At 6:30, I woke up to find the car still charging. I thought the OpenEVSE should have cut the charging at 6:00.

Existing Code
I looked at the code for DelayTimer::CheckTime(). The condition to stop charging is when (m_CurrTimeSeconds == m_StopTimerSeconds) is true.

Now, the definition of m_StopTimerSeconds and m_CurrTimeSeconds are

uint16_t m_StopTimerSeconds = m_StopTimerHour * 360 + m_StopTimerMin * 6;
uint16_t m_CurrTimeSeconds = m_CurrHour * 360 + m_CurrMin * 6;

Also, CheckTime() is set to execute by a timer interrupt every minute.

What I think happened
Because the condition to stop charging is checked by a timer interrupt, it is possible that the checking is missed at 6:00. For example, the two consecutive checks this morning could have been at 5:59:59 and 6:01:00. This misses 6:00.

What can be done?
If the above is true, then we can either

a) reduce the timer interrupt interval, say to every 55 seconds, or
b) change the check condition to
(m_CurrTimeSeconds == m_StopTimerSeconds) || (m_CurrTimeSeconds == m_StopTimerSeconds+6)

Another comment
It seems like the factor of 6 in m_CurrTimeSeconds is not needed since the seconds are never tracked. So the code could have been the following instead

uint16_t m_StopTimerMinutes = m_StopTimerHour * 60 + m_StopTimerMin;
uint16_t m_CurrTimeMinutes = m_CurrHour * 60 + m_CurrMin;

Any comments?

 

[davewill]

... Any comments?

Any reason you shouldn't just use (m_CurrTimeSeconds >= m_StopTimerSeconds)? There are any number of reasons why an interrupt could be missed/late, and it really shouldn't matter by how much you've missed.

 

[greenleaf]

... Any comments?

Any reason you shouldn't just use (m_CurrTimeSeconds >= m_StopTimerSeconds)? There are any number of reasons why an interrupt could be missed/late, and it really shouldn't matter by how much you've missed.

There could be some reason why the original author didn't want to check beyond the "same minute". So I only propose a change that does not change the code intent too much.

 

[GlennD]

AS a user only I am not qualified to comment on code. I do know almost of the ram is used up. That is the reason CLI is disabled to free up ram.

... Any comments?

Any reason you shouldn't just use (m_CurrTimeSeconds >= m_StopTimerSeconds)? There are any number of reasons why an interrupt could be missed/late, and it really shouldn't matter by how much you've missed.

There could be some reason why the original author didn't want to check beyond the "same minute". So I only propose a change that does not change the code intent too much.