DeltaQ Charger failed in my ZAP

[Puppyjump]

My DeltaQ failed on my 2008PK that I bought last Dec 20. It slowly died over a week's time. Symptoms were the output amperage would flutter, jumping from 0 to 15 amps at the beginning of charge. It would flutter irradically for about a minute before finally stabalizing at 15A and working normally for the duration of the bulk charge and the finishing charge stages.

Now it just flutters between zero and 5 amps for about 10 seconds and then stays dead. It will do this each time I plug in the 110V to it.

The unit's AC light is normal and indicates no error, so the problem seems to be the output stage FETs probably failed.

The alg43 is normal for my AGM pack as the appropriate LED blinks 4 times and 3 times when the unit is powered up while not connected to the battery.

I don't suppose ZAP will change it even if it's under warranty since they have no money, so I'm sure I need to either send it directly to DeltaQ for service, or else just buy a new one for $600.

So now if I have to buy one the question is should I buy an 84V unit now and get rid of my separate 12V guest charger for the 7th battery? Is there a better brand to buy compared to the deltaQ

 

[dnmun]

you should ask them if they will help. even if they are broke, they may have something available to help you, maybe they have an experimental 84V charger too. i assume they would rather let their customers have the stuff rather than go to a receiver who has no idea of how to use it effectively. maybe you can figure out how to fix it too, they may even have some internal documents on maintenance and how to repair the chargers, so go ask them.

 

[Roy Von Rogers]

Did you ever get that charger fixed, whats the news...Inquiring minds want to know

Roy

 

[dnmun]

yes, wondered how it turned out. did you talk to anyone at Zap?

i had not realized they went bankrupt. but if the charger was made by someone else then they may provide warranty service. sounds like an easy fix. but if they have stuff there they may want someone loyal to have it rather than go to bankruptcy liquidation.

maybe your controller will handle another battery and you can go to 96V nominal and find a new charger at that level.

 

[Puppyjump]

Good update. I originally sent an inquiry directly to Delta-Q. I figured ZAP was too small to support the need to diagnose my bad charger. But I was wrong....

Approx timetable:

Week1: My ZAP sits while I figure out what to do. My wallet opens again to Chevron while I drive my gas car.
Week2: Sick of having to pump gas, I use my ZAP again minus the charger. I instead charge it by directly rectifying 110V AC, ramped to the appropriate level to send about 5A into the pack with a variac, and connecting it to the battery pack and monitoring AH and SOC using my new instrumentation such as the cycle analyst computer, etc. Meanwhile I have an email to Delta-Q describing the failed charger and asking for an RMA. I get an email from ZAP tech support. It turns out Delta-Q forwarded my email to ZAP. ZAP asked me to return my charger to them, which I did.
Week3: A new charger comes in the mail. ZAP tech support verified it was bad and sent me a new one. It was all free.

I'm a happy camper again...but...why did my charger fail? I ran a temperature test to see if it's running too hot:

I measured my charger temp at its heat sink fins after an 8 mile drive and then recharging the pack.

A hot day, 94F.

Time(mins), Temp (degC), Charge output current (Adc)
0, 32.2, 0 bed closed
0, 32.2, 17 Plug in charger cord
5, 44.6, 15.8
10, 53.0, 15.0
15, 56.8, 13.9
20, 58.1, 13.9
25, 60.4, 13.9
30, 61.9, 13.8
35, 62.9, 13.8
40, 63.7, 13.7
45, 63.3, 13.7
50, 64.0, 13.5
55, 63.8, 13.4 open the bed for air flow to charger
60, 59.7, 13.7
75, 50, 0-15 cycling phase, charger clicking on and off

>It seems I could benefit by adding a cooling fan to blow onto the charger. I bought a 50 degree C thermal switch from eBay to be mounted to the heatsink. When the charger warms to 50C, the fans will turn on.

> Also, I noticed the AC line cord sparks dramatically when I plug the ZAP in for a recharge. Fearing a surge into the charger may cause it to fail, I obtained a transorb Transient Voltage Suppressor and connected it to the AC power line where it enters the Delta-Q.