# Manzanita charger woes, looking for a solution



## jtgreeson (Aug 14, 2009)

*Manzanita charger woes, (edit solution found*

Here's a quick Good, Bad & Ugly story. I'm looking for comments or advice.

I received my new Manzanita PFC-30, all nice and green. I cleared up some ambiguity in the operators manual and verified how I'll integrate the VoltBlochers into the RegBus by spending some time with it charging a couple of 12v car batteries hooked up in series (24v). After installing it into the car and finishing the wiring to the 48 TS 180AH battery pack it was time to do the first charge. (drum roll, anticipation, etc). It works! This EV stuff is fun. (the Good). Working slowly I start measuring currents and voltages as I charge the pack for the first time. I had planned to do just the first charge to 4.2 volts like the manufacturer recommends. (some recent discussions on that lately on this forum and elsewhere) Output with 240vac input and the Amp Knob turn to max was about 28amps. Then the Bad. I accidentally popped a 30amp fuse, disconnecting the charger to the bank. Then the UGLY, with no sound, the charger stopped it's happy output. I knew all the warnings, read where others had "blown" their Manzanita's, but thought I would be careful and avoid it. No such luck. Green light on charger ok but little change to DC output when the Amp trim pot turned. Oh well, box it up, mail it back to Kingston, WA and wait for the bill.

Like others have written here, I wish the folks at Manzanita would have included a protection circuit. But....would something like this work:

A laptop AC charger (or any suitable "wall wart" ac to dc converter) connected near the PFC-30 DC output and wired to a SSR (solid state relay) controlling the AC input to the charger. Add a manual "Charger on/off" switch to the low voltage output of the laptop charger and maybe another relay to send a "charger on" signal for the Zilla controller and EVision instrumentation.

This would definitely protect the charger from initial starting with no DC load. But, will it's own output prevent the AC SSR from turning it off if a fuse is blown during charging?

Has anyone figured out a soultion to this problem? I really don't want to connect the charger to the pack directly with no fuse protection. That would require extra wires fore and aft plus the possibility of a short later on.

Thanks for any input.


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## Travdude (May 11, 2009)

The Manzanita charger has an output fuse inside the case.

It does seem like a good idea to build some sort of interlock to prevent powering it up when disconnected from the pack.

I am using SSR's for HVC and LVC with my Voltblochers and I am having problems with them going crazy when I drive the car. Must be the EMF from the controller. Might want to consider that.


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## jtgreeson (Aug 14, 2009)

Thanks for the ideas Travis. My conversion is similar to yours with TS-LFP's, Zilla, Warp9, VoltBlochers, and Manzanita. I've considered the EMI problem. So far I've twisted the HV cables when able and ran them down the opposite side of the car from all the LV and signal wiring. I hope that is enough. Do you have anymore details on the interference problems you have had that might help? Any solutions?


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## tomofreno (Mar 3, 2009)

There is a 50A fuse in the charger output, so I don't see why you need another in series with it. Littelfuse L50S 50.


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## Travdude (May 11, 2009)

My HV and LV is on separate sides of the car as well. Not twisted though, just tie-strapped together.

I think the small wires going to each one of the VB's is what is picking up the interference. I have tried a few things but have not come up with a solution that works. Going to do some research, if I find anything I will let you know.


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## gdirwin (Apr 7, 2009)

Sorry to hear about your charger... I also am using the same gear (Warp9, TS, Zilla, PFC40M Manzanita... but Elithion BMS) - to minimize EMI, I will put all LV wiring in some sort of conduit that has a metal mesh layer in it (and grounding this layer). I haven't searched yet, but ideally a flexible conduit with a metal screen layer... 

RKM found something, so will check with him...

For the Manzanita charger, I will connect an AC relay to the input to the charger as a fail-safe - if the BMS detects a FLT (ie if any cell is above a threshold or below a threshold, temperature etc...) it will indicate a fault and this will open the AC relay (this is all in addition to the normal way to slow down or shut down the charger via the REGBUS)... 

After reading your post, it would also be good to open the AC relay (and disconnecting the charger) if the DC battery is ever disconnected (or a fuse blows etc...).

To detect the presence of the DC pack voltage, I found this for $55:
http://atkinsonelectronics.com/product_pdfs/VRDC-200V.pdf

There maybe cheaper/better HV DC relays as well... Please post anything else you find!


Out of interest, how will you slow down the Manzanita charger to a low amperage (below the shunting capability of your BMS)? I know you can connect resistors (see this thread: http://www.diyelectriccar.com/forum...ip-switches-cheap-bms-voltblochers-39837.html) to slow it down to 2 amps (for example).


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## tomofreno (Mar 3, 2009)

> A laptop AC charger (or any suitable "wall wart" ac to dc converter) connected near the PFC-30 DC output and wired to a SSR (solid state relay) controlling the AC input to the charger.


 Hmmm, seems you could just use a fuse in series with a resistive voltage divider to power a N.O. ss relay with 12V "coil" and 240AC switch side. Connect the divider directly between the output leads of the charger, so if the leads are connected to the pack it has the full pack voltage across it and divides it down to about 12VDC input to the relay (choose R's so minimum pack voltage gives minimum DC voltage required to turn on the relay, say about 5VDC for the relay below). Wire the charger AC input through the AC side of the relay. Then as long as the charger outputs have voltage in the typical range of your pack voltage, the relay will be on connecting AC to the charger. Use the charger's on/off switch to turn it on/off as usual. If the charger becomes disconnected from the pack, there will be no voltage input to the divider so the AC input relay will open. Use large value resistors to limit current, and a 0.5 A fuse. For example the Crydon HD12D2440D relay has 4 to 15VDC, 13mA input and switches 48 to 280V/40A AC. This would of course give a bit more than constant 13mA drain on your pack, so drain a bit more than 1.3Ah in 100 hrs. 

Myself, I think it is sufficient to just bolt the leads of the charger directly to the pack. Then it has a load unless you disconnect leads in the pack and turn on the charger for some reason.


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## jtgreeson (Aug 14, 2009)

Tom, Thanks for the input. That's a great idea using the resistors with a SSR. I think your last idea to connect directly is the best. Simpler and less likely to fail. That's what I've done today. 

I ran an extra set of wires from the pack dedicated to the charger. I still have a 250 amp CB that divides the front and rear pack that would break the charging circuit. This will not trip under normal charging currents amounts. To warn me in case I've tripped it on purpose during maintenance I wired in a warning light. I used an LED with a 68k ohm (1 watt I think) resistor and wired it to the DC output of the charger. That gave about a 3 mA current to the led, dim but very much visible. This is on my 156 volt pack. I should be good over the operating voltage of the pack. The max current for this led was 20 mA but the larger resistor kept the current draw low (less drain on the pack over time) and more importanly kept the resistor from overheating. If the light is not on I will not turn on the charger.


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## jtgreeson (Aug 14, 2009)

Thanks for the comments gdirwin. That's a neat DC pack voltage sensor you linked to. 

As far as EMI I think I'll use shielded cable between all the voltblockers and ground the shield to the car chassis. Would that help or not worth all the effort?

I will post how I slow down the charger after I've got some real world experience. It might be a month or two before I get to that point. For now I'm just planning on a resistor in my HVC circuit between pins 1 and 2 on the RegBus. The resistor and proper setting of the volts and timer settings on the Manzanita should do the trick.


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## etischer (Jun 16, 2008)

I think your problem is noise from the charger. I had a similar problem with my voltblochers (brians original design). I added filtering caps to the board to eliminate the high frequency noise from PWM output of the charger. 





jtgreeson said:


> As far as EMI I think I'll use shielded cable between all the voltblockers and ground the shield to the car chassis. Would that help or not worth all the effort?
> 
> I will post how I slow down the charger after I've got some real world experience. It might be a month or two before I get to that point. For now I'm just planning on a resistor in my HVC circuit between pins 1 and 2 on the RegBus. The resistor and proper setting of the volts and timer settings on the Manzanita should do the trick.


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## azdeltawye (Dec 30, 2008)

jtgreeson said:


> ....
> Like others have written here, I wish the folks at Manzanita would have included a protection circuit....
> 
> Has anyone figured out a soultion to this problem?....quote]
> ...


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## JRP3 (Mar 7, 2008)

How does setting voltage 50 volts above whatever pack you have help protect the charger if it's turned on when not connected to the pack? Since essentially there is no pack in that case why would 50 volts above some pack voltage matter?


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## tomofreno (Mar 3, 2009)

> I wired in a warning light.


 That should work - as long as you pay attention to it. You could follow a modification of logout/tag out safety procedures. Shut off the AC breaker you charge from, lock the box, and tag it something like "Work in progress. Lock to stay in place until charger reconnected to battery pack." Bit of a pain, but would prevent you or someone else from starting it up disconnected.


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## tomofreno (Mar 3, 2009)

> How does setting voltage 50 volts above whatever pack you have help protect the charger if it's turned on when not connected to the pack?


 Maybe depends on voltage limits of components. He said it would work for something like a 156V pack or so. That is somewhat comforting since my voltage limit is set to around 120V (would sure be nice be able to determine what it is set at prior to turning on the charger).


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## azdeltawye (Dec 30, 2008)

JRP3 said:


> How does setting voltage 50 volts above whatever pack you have help protect the charger if it's turned on when not connected to the pack? Since essentially there is no pack in that case why would 50 volts above some pack voltage matter?


The way I understand it they set the internal HV limit on these chargers to about 450V at the factory. This is a different adjustment than the multi-turn pot on the front. So when you open circuit the charger (current source) it will rapidly increase the output voltage until it hits the HV limit set point. However at this voltage level it is very close to the max voltage rating of some of the components and thus there is very little margin. In other words it’s on the hairy edge of self destruction. By reducing the internal HV limit in the charger you dramatically increase your margin and the chances of the charger surviving and open circuit condition. 

I did some searching in the EVDL archives on Manzanita chargers and found a post from Joe Smalley – the engineer who did the design on the PFC chargers. He described adjusting trim pots RV41 and RV49 to reduce the high voltage limit on the power output stage to about 50 volts above your nominal pack voltage. Now obviously if you have a 400V battery pack this will buy you nothing. But if your pack is 144V and you set the HV limit to 200V you will have 250V of additional margin and shouldn’t have to worry about an open circuit charger failure. 

In my email to Rich Rudman I asked if there was a procedure for performing this adjustment to reduce the HV limit. His response suggested that it would be better to specify your maximum voltage upon ordering the charger and have the factory tweak the pots. He also said for additional protection you could add a 5000uF cap to the charger output. The additional capacitance will increase the charger time constant allowing the over voltage shut down protection circuit more time to catch the open circuit event.


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## jtgreeson (Aug 14, 2009)

Darren, Thanks for that info from Rich Rudman. I emailed the factory to see if they would do it for mine while it was in for repair. I'll let you know what they say.

Tom, Good idea with the safety tag. Sort of like a "do not fly" ribbon on a pitot cover.


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## JRP3 (Mar 7, 2008)

OK that makes sense. The only drawback is if in the future you want to go to a pack voltage higher than 50 volts above the current setting then I guess you'd have to send it back in, or figure out how to adjust it yourself.


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## tomofreno (Mar 3, 2009)

> I did some searching in the EVDL archives on Manzanita chargers and found a post from Joe Smalley


 Do you remember the number or date of the post? Did he describe how to determine the voltage limit as you set the pots?


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## azdeltawye (Dec 30, 2008)

tomofreno said:


> Do you remember the number or date of the post? Did he describe how to determine the voltage limit as you set the pots?


 
It was back in Dec 2007. 

Re-reading that post from Joe it looks like I miss-quoted him. He said set the limit to 40V above max pack voltage, not 50V above nominal.

Here's the message in its entirety:

Dec 02, 2007; 05:29pm 
Joe Smalley


Yes, there are a few things that can cause the PFC to lose its ability to 
regulate. 

1. Internal Voltage reference generator went bad. 79 cent part. 30 minute 
repair time. 
2. Open trace from output connector to voltage sensor. Solder wire across 
open trace. 30 minute repair time. 
3. Open resistor from output connector to voltage sensor. 5 cent part. 30 
minute repair time. 
4. Remote Control switch is switching to the wrong control input. If you do 
not use the remote port, the best solution is to remove U15, install a 
header with jumpers from pin 12 to 14 and from pin 2 to 4. 15 minute repair 
time. 

======================================================= 

Operating the charger with no load on the output has a 50% chance of blowing 
the output transistor. With that kind of odds, the answer is "Don't Do It 
Intentionally." You can reduce the probability of damage by reducing the 
regulation voltage and abort voltage settings on the main power board. 

There are two pots called RV41 and RV49 that limit the output voltage of the 
power stage. 

RV41 is a graceful cutback with a slow integration time to allow the charger 
power board to operate into a load without a charge controller board. It is 
not fast enough to catch an open circuit condition but should be set to 
about 20 volts above any battery voltage you expect to see. 

RV49 is a violent shutdown that will shut the charger power stage off within 
1 microsecond. This shutdown is fast enough to catch an open output if the 
threshold is set low enough that the energy stored in the boost inductor can 
be safely stored in the output capacitor without reaching dangerous voltages 
on the output transistor. It should be set to about 40 volts above any 
battery voltage you expect to see. 

======================================================= 

I was in the Manzanita Power Shop late last week and Rich had a lot of 
chargers sitting on the repair table. It seems that users are not checking 
their gensets for peak voltage before plugging a PFC charger into the 
genset. The power stage has no problem with peak voltages over 400 volts but 
the logic power supplies die very close to 400 volts peak on the 240 VAC 
waveform. Once the logic power supply dies, the lights go out and no power 
comes out of the charger. Please check the voltage waveform on a genset 
before running a PFC charger from the genset. As far as I know, there has 
never been a problem with a charger running on 120 or 208 VAC from a genset. 

Bad logic power supply. $100 part, 20 minutes repair time. 

======================================================= 

When Rich repairs a charger, he spends more time verifying that the repair 
was successful that he does making the repair. When the charger is returned 
to the user, Rich is confident that it meets all applicable product 
specifications. 

======================================================= 

The above comments are my opinions and observations. They are not price 
quotes, permission to void your warrantee, permission to do something 
dangerous or beyond your skill level. Prices and repair times may no longer 
be current. Call Rich to get the official word. 

======================================================= 

Rich can install some options in older PFC chargers. 

Sending him a PFC-20 and asking him to make it into a PFC-30 is like asking 
your Ford dealer to upgrade a Focus to an F-150. Not a lot of parts are 
carried over. It is better to sell the PFC-20 and buy a PFC-30 to get 
exactly what you want. 

======================================================= 

*Joe**Smalley*
RuralKitsapCountyWA
Former owner of 48 Volt Fiesta 
NEDRA 48 volt street conversion record holder​


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## jtgreeson (Aug 14, 2009)

Solution found:

Not the best but this is my setup now: Installing repaired Manzanita charger (they charged $150 which included return shipping) and connected it directly to pack, no additional fuses. Added a status/warning led to let me know that there is pack high voltage present before I plug in the charger. I Had Manzanita Micro adjust the max voltage of the charger to 250 volts after they did the repair on it.

Thanks for all the feedback from everyone!


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