Overlander D100v2 Problems

[Robert Cracknell]

A shot in the dark perhaps but is anyone experiencing problems with the Overlander D100 V2 charger?

 

My problems started with cycling a 4.8v 2600mah Vapex Rx pack supplied by Component Shop. I connected it up to the D100 and set it to cycle with a discharge of 1.0A down to 1.0v/cell followed by a charge of 1.0A (0.38C) During discharge I noticed that the cell voltage was rising – from an initial 4.1v the reading rose to 4.3v. Realising that the discharge was not going to terminate I disconnected the pack.

 

The second problem arose when I was cycling a 950mah AA Rx pack (again a Vapex pack from the Component Shop) settings were discharge down to 1.0v/cell then charge at 1.0A (1.05C) With such low settings I left the pack to cycle as I had done many time in the past. I came back some 20 minutes later to find that the pack was very hot and had ruptured.

 

Both packs had been cycled in the past with no problem.

 

I have video and photographic evidence of both these instances which have been relayed to Overlander.

 

I have sought advice from Overlander and to say I am disappointed would be an understatement. Their initial response was one of denial suggesting the packs were at fault. I spoke to the Component Shop and their response was that if we had discovered cells that increases in voltage when discharging we would have solved the worlds energy needs! Realistically they surmised that the common denominator was the charger – 2 packs with problems  -1 charger!

 

I have contacted Overlander and I have heard nothing constructive in 3 months, My last email (one week ago) has gone unanswered.  I know the charger is out of warranty but so is my Ford car but the dealer is more that happy to accommodate my servicing needs.

 

My questions are as follows…

 

Has anyone on the forum had any similar experiences?

 

If the firmware is corrupt would you trust connecting a LiPo to the charger?

 

Is Overlander a ‘Sell and Forget’ operation?

 

Suggested future course of action?

[RottenRow]

Robert, I haven’t any specific answers to your questions I’m afraid, but would add that there could also be a hardware fault within the charger (ie it doesn’t have to be a firmware corruption that could cause the problems that you are experiencing). Unrelated I know, but I had a Pro Peak fast charger a few years ago that on a couple of occasions went from a specific charge current (it had a meter on the front) to off the scale. Opening it up revealed solder flash on the circuit board. Clearing those solved the problem.

 

As to your charger, were it mine, I think I would do a couple of things:

 

1. Carry out some tests, using some old battery packs, with an ammeter inserted into the charging lead. This will show (a) whether the current actually in the battery circuit is the same as that indicated on the display of the charger, and that it is as selected, and (b) if the current is flowing in the right direction all of the time (out of the battery for discharge mode). I would make up a ‘break-out lead’ for this purpose, with the ammeter inserted into the positive lead.

 

2. Also, as the V100 has two channels, I would check both and see if there is any difference between them. A hardware fault would likely manifest itself on only one of the channels.

 

I have no idea with regard to the level of service or expertise provided by Overlander, but the charger is only branded and sold by them, not manufactured by them. It’s surprising that you’ve heard nothing though.

 

Brian.

[Robert Cracknell]

Brian

Thank you for your feedback and suggestions. I will give them a try on the next rainy day!

I'm still reluctant to let a LiPo near it though...

[RottenRow]

5 minutes ago, Robert Cracknell said:

I'm still reluctant to let a LiPo near it though...

Yes, I think I would want to be pretty confident of its reliability first!

 

Brian.

[Phil Green]

As part of a discharge cycle a charger will often remove the load briefly in order to take an intermediate float voltage reading, this would account for the voltage rising but should only take a short time, probably no more than a minute or so, but it could happen several times during a cycle. During this time the voltage will 'recover' significantly from the on-load voltage so will appear to climb. Incidentally the difference between on-load and off-load also contributes to the esr measurement.   From the ruptured pack it sounds as though the charger isnt detecting the NiMh charge peak, this could be caused by packs with differing SoC per cell not peaking together which can happen in brand new packs, a long trickle charge will unify them.

You'd need to spend some time investigating properly to find out for sure 🙂

 

 

[Robert Cracknell]

Thanks Phil, valuable info.

The 950mah pack was being charged at just over 1C and was destroyed in about 30 minutes. I would have thought this was a bit drastic for such a low charge current.

[RottenRow]

From your first post, I thought the 950mAh pack failed within 20 minutes of being put on a discharge / charge cycle. Most, perhaps all, of that 20 minutes would have been taken up by the discharge part of the cycle, surely?

 

Could that discharge (presumably 1.0A) have heated the battery lead sufficiently for the insulation to melt through and the wires to short together? That would then short circuit the battery, resulting in a very high current, definitely enough to cause the pack to rupture. If you still have the remains perhaps you could check the condition of the wiring, including its exit point from the pack.

 

Brian.

[Frank Skilbeck]

My D100 V2 is working fine on Nimh batteries, I have noticed in the past that a Nimh battery can show a slight voltage recovery underload as it warms up and then falls from.that, but thats on other chargers too. But it may also be a component in the charger getting warm too.

 

On mine the other day it didn't properly balance a lipo and one cell ended up above 4.2v so I'll have to keep an eye on that.

[Robert Cracknell]

Brian, the leads were all intact after the incident. The common factor with the two packs is that the voltage increase was steady whilst discharging. I assume (and stand to be corrected) that no current should be going into the pack when discharging. The wiring on the 950 pack was also in good condition indicating that the damage came from within the cells.

Both packs had been reliable and cycled before with no problem. 

[Frank Skilbeck]

Robert, you are correct no current should be going into the battery, but on discharge a cold battery will warm up which can increase it's output which gives a slight voltage increase. But this will only be temporary.

 

It could be on your charger that the software is charging on the discharge setting rather than discharging. If you don't use the cycle function and just do a single discharge what happens?

[Robert Cracknell]

Good point Frank. When I set up with the test leads I'll check that out.

[PatMc]

Robert is it possible that you have accidentaly selected the "charge - discharge" option instead of "discharge - charge" ? 

Which of the options is first choice or default on the charger menu ?

Edited May 29, 2024 by PatMc

[Robert Cracknell]

Pat, thanks for your post, on the D100 the display shows D or C depending on what the charger is doing. On the video I sent Overlander you can clearly see the D (discharge) option flashing whilst the pack voltage is rising. I videoed it for about three minutes while this was going on.

[Frank Skilbeck]

Robert, just did a test on my D100 v2 with two different batteries, the first a Radient 2000 mah AA 4 cell, on discharge at 1.0A, voltage dropped to 4.05v and then recovered to around 4.2v and stayed there for a while before dropping off, a 3300 mah subC pack didn't show the same characteristics with no voltage recovery, it dropped as the amps ramped up and then stablised. I only ran the tests for a 5 mins. But my conclusions are that the high load on the radient pack cause a bit of internal warming which improved the reaction giving the battery a bit more umph, the Sub C cells being so much larger didn't see the same effect.

 

My other Pro Peak charger has a max discharge of 0.5A and on the Radient pack the voltage didn't dip as much under load or show any recovery, possibly because there was reduced internal heating.

 

BTW tried 1.0A with a older 4 cell Eneloop pack and it couldn't maintain 4v.

[Robert Cracknell]

Frank, thank you for trying these things out. My concern is that cycling these same cells at the same settings on previous occasions I have not seen this phenomenon happen before.

I am not infallible and appreciate all the background and suggestions and will try out many of the tips to see if I can bottom it out.

Thank you all for your help - which is a lot more than I got from Overlander. !

[RottenRow]

I forgot to ask you Robert; you mentioned that the charger is over a year old. Have you only just recently started using it on NiMH batteries? Or have you done so for the past year without any apparent problems until now?

 

When you make your test measurements, if you have sufficient equipment it would be useful to measure the battery voltage at the same time as the current, just to make sure that it does actually increase, and it's not something within the charger showing something that isn't really happening.

 

Frank's findings and conclusions seem feesible. It would be interesting to see what happens with the Radient pack if the discharge were stopped once the voltage had risen slightly, then restarted shortly afterwards (ie with the cells still slightly warmed from the first discharge).

 

Brian.

[Robert Cracknell]

Brian, I have used it on NiMh since I bought it. Your suggestion about monitoring voltage as well is good one and one which I shall try.

[RottenRow]

Robert, I just had another thought...

 

In cycle mode (discharge then charge), when the charger senses that the battery has reached its discharged state (determined by the 1.0V per cell setting, so 4.0V in this case), it goes into a 'rest' mode before starting to recharge the battery. The rest time is adjustable, I can't see any mention of what the default value is in the manual, but probably something like 5 or 10 minutes. During this time, the battery voltage will rise as the battery is no longer connected to the load.

 

The manual isn't specific, but as the charging part of the cycle hasn't yet started, the display may well still indicate that the discharge part of the cycle is still active (the flashing D). If this were the case the actual current reading should be zero at this time.

 

In discharge only mode (not cycle), when the end point is reached the charger display shows a suitable message and beeps.

 

I know this wouldn't account for the damage to the second battery, but it's something else to investigate.

 

Brian.

[Robert Cracknell]

Thanks Brian, further food for thought..!

[Nigel Sharp]

I have one of these chargers great. Except my 12v input socket is now defunct. Anyone know if it has an internal fuse?

 

Then of course the best way to disassemble to get to it.

 

Obviously it's working from 240v so am slightly reluctant to make it completely non-functional.

[Barnstormer 52]

Robert 

There is an app for a PC that you could download from Overlander - Charge Tracker

Not sure if you can still get it as the charger seems to have disappeared from the website.

You can watch the charge and cycle process and it creates graphs which can be viewed, this might help.

I have 2 of these chargers and have only noticed 1 fault - while charging a Futaba Lilo Tx battery at the end of the charge there is an error message rather than a charge complete message - I haven't actually got around to watching it on Charge Tracker.

If you can't get the app from Overlander I think I still have the download.

Geoff

[Robert Cracknell]

Geoff

Thank you for your post. I have recently downloaded  Charge Tracker thank you. If you download the app onto your mobile it also allows you to remotely control the D100 via Bluetooth.

Rob

Edited May 31, 2024 by Robert Cracknell
Addition

[Barnstormer 52]

Hi Robert

I meant the PC version creates a graph and it might be more obvious what is happening

Geoff

Geoff

[Robert Cracknell]

Geoff

I have both PC and smartphone apps and will give the PC version a go.

Thanks

Rob