Tuning a 36V/4A Charger: HP8204L3

Before I tinkering off the deep end I would like a bit of help please:
Last year I bought a High Power Li-Ion Battery Charger, Model: HP8204L3.

It’s been a nice little unit and seems pretty solid. I recently switched from LiFePO4 36V battery system to a 10S 37V LiPo system and this charger still performs admirably. However I must note that I find it caps off the charge a little on the high side at 43.6V, and I would like to trim that down a tiny bit to a safe 42.5-43V range.

Here is a picture of the inside; as you can see there are 3 trim POTs on the left. The small white 2-Pin Molex connector immediately right of the POTs is for the fan, and the larger 2-Pin Molex to the far right below the aluminum heat sink plate is DC Out +/-
I need just a bit of hand-holding here:



Could one of you fine folks explain which POT adjusts what aspect, identify the test points, and how best I can twiddle this critter down please?

Sidebar; I actually have another request as well:
Sadly I recently bought three Meanwell SP-320-48 PSUs but it’s looking like these are more trouble than they’re worth to modify.
I am open to alternatives. Would it be possible to take the 48V/16S 3A LiFePO4 Smart Charger version and ramp it up to 63V for a 15S LiPo configuration?

Thanks very kindly, KF

Hmm. I was hoping for a byte.

Spoke with Justin at eBikes.ca and he didn’t have any info to offer; he said I was better off just putting a couple of diodes in-line to drop off the required voltage. Went to Digikey and spec’d these out:

• P/N 6A10DICT-ND: RECTIFIER SILCON 1000V 6A R-6

I'll try one in-line; should knock the voltage down to 42.7, and if it gets hot enough to fry bacon I guess I could put another in parallel.

I'd just put a voltmeter on the charger, and start twiddling the screws one by one. Start with one of em, turn a bit, and if nothing happens, put it back where it was. On to the next one. One will be likely to adjust the voltage. Carefull with the metal screwdriver in the open case while it runs!

Yep what he said. My Ping 48v charger had 2 pots and one got it to 65 volts where I wanted it. In my case (pun) I had to use the Dremel to open it, Good luck twiddling!
otherDoc

Clearly I am in the League of Honorary Gentlemen!
Thank you for the encouragement! I, KF, did hereby go twiddling today. If you may be so kind as to direct your attention to the image below:

• Notice that there are 3 POTs; let’s call them Top-Left (TL), Top-Right (TR), and Bottom-Right (BR).
• I hooked up my multimeter to the Plus/Minus of a spare length of power cord and connected the other end to the charger.
• Tested charger at start-up: LED on left lights-RED, voltage ramps to 43.6, and second LED on right goes AMBER (charging mode). Current draw (Amps) not recorded.
• After a few seconds, LED-AMBER goes GREEN (charging is complete). Voltage stays at 43.6. I cycled this a few times to ensure stability and accuracy of measurement; there was no drift.

Twiddling:

• After start-up and right LED lights GREEN (no time to twid whilst cycling up), dialed BR POT both in CW and CCW directions: No affect perceived or recorded.
• Twiddled TR in the same manner, and also received like result :|
• Repeat with TL, and … BINGO! We have a winner:
  • Tuning Top-Left POT CW to limit reduces output to 36.2V consistently after several attempts.
  • Tuning Top-Left POT CCW to limit increases output to 50.4 consistently after several attempts.
  • I returned the POT adjustment to precisely 43V, concluding my effort. The setting is quite stable after repeated cycling.

Perhaps someone more skilled can ascertain the reason for the two right-side pots. I, however am quite satisfied, and I shall conduct a field charging test on one of my LiPo arrays.

Again, thanks for the show of support, KF

see if the manufacturer will give you a clue. otherwise we need to identify where those pots are in the circuitry and what they are connected to.

Addendum:
Charged two 10S LiPo arrays today and in both cases the battery packs topped out at 42.8V after the charger had completed (LED went GREEN).

Good enough. Now, on to my next quest... finding a 15S charger! 8)
Cheers, KF

try to keep 10S lipo under 41.2V.

from what gary has said, charging to 4.2V eats up life cycles and you don't get very much extra charge to begin with over 4.12V.

...charging to 4.2V eats up life cycles

Click to expand...

Gotcha. I had been thinking about this earlier and I’ve since derated it down to 42V. After tomorrow’s ride I can twiddle it some more. At least I have discovered how to control it; one less worry in Life 8)

Addendum:
Cycled charging with it set to 42V. 10S3P LiPo pack topped at 42.0V exactly. I expected slightly less, but then it was still charging when I went to bed so perhaps the GREEN LED lights when it’s within 99% though continues to trickle.

On the ride, my hot speed was off a tiny bit, and I noticed I was down 0.5V at my destination (halfway point), but I was still above 37V on the return, so no great loss on range. I will continue to monitor and twiddle…

41.2V, no more than 4.12/cell will provide longest life according to the expert.

Kingfish said:

Could one of you fine folks explain which POT adjusts what aspect, identify the test points, and how best I can twiddle this critter down please?

Click to expand...

KF - you already figured out the hard part.

View attachment 3_pot_charger_adjustment.jpg

The other two pots should be output current and the end of charge current point. Sorry - I used to have it documented but can't find my notes.

Andy

dnmun wrote:
41.2V, no more than 4.12/cell will provide longest life according to the expert.

Click to expand...

Understood. Done; set to 41.2V. Discharging currently charged batt-packs to 41.2V 8)
Thanks!

Hopefully by the time I am done troubleshooting and fixing my HP8204L 16S charger I'll be able to contribute some detailed info to this thread. For now, the troubleshooting portion in progress is here:
http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=18616

I did quite a bit of searching around on this series of chargers, and found basically no info other than what is here at ES, and a few different Chinese manufacturer and directory pages that show specs and features on this 36V 10S version and some other NiMH and PBA versions (but not my HP8204L 16S). I haven't even been able to find the *actual* manufacturer site for "HighPower" that appears to be the originator of these.

There were a few pages of various sites that Google said it found my charger number on, but even Google's cache does not contain it anywhere within even the source, and definitely not on the current pages.

That HP8204 charger is sold here in Australia, rebadged, by a number of companies including The Electric Bike Co (TEBCO) and Electric Vhicles (EVS).

I think it may be made by Elite Electronics Co Ltd

According to test results the sweet spot is around 4.15V for maximum charge/discharge cycles with minimal reduction in ouput capacity. https://endless-sphere.com/forums/viewtopic.php?f=16&t=9268 and http://www.powerstream.com

There are some losses between the charger output and the actual cells due to fuses/cables/connectors/BMS in my case so I set my chargers to 41.75V.

The HP8204L3 chargers are quite robust with alloy case and fan and one of the better ones I have seen sold in Australia. Can get them for around $150 from Glow Worm Bicycles or Electric Vehicles aka EVS. They are/were also used with eZee, Wisper, Green E-Wheels, Currie, etc.


Edit: updated pricing

User Manual pages 1 & 2

I used Kingfish's experimentally-verified directions to turn pot TL counterclockwise and raise the voltage on an HP8204L3 I got from Dirtdad/Comcycle's super-clearance a while back, from the 60.8V it came at to 66.4V, to use with a 16s experimental LiPo type pack.

Yeah, I know it's a LiFePO4 charger...but we'll see how well it works in this experimental application.

It is topping off the pack right now, which had already been near full (~4.1V/cell), before I added 2s to it's original 14s (after I drained them down with a car headlight just a tad to match voltages with the originals).

I didn't want to mess with the other charger I got in the same sale, which is a different kind and was already set to the perfect 58.3V for charging my 14s RC LiPo ammocan pack (and this experimental one prior to adding 2s to it), until I am sure I want to keep this pack at 16s, or if I want to move it up to the full 18s or back down to 14s.

I would've gone right to 18s (74.7V for 4.15V/cell), but this charger won't go that high--it only goes to 67.0V, so the closest I can get is 16s.

I'm hoping the other charger can be made to go to that 74.7V, but I'm not experimenting with it until I am sure this one works fine, so I have a backup.

This one is only a "3A" charger, and the other is 4A. FWIW, this charger's initial current was about 2.5A, which increased to over 5A during a period of 15-20 seconds, then it went back down to less than 1A, then back up to 2.5A, and swinging back and forth like that for a while. Eventually it settled down to around 1.8A and slowly dropped over the first 0.8Ah of charge to about 0.9A it's at right now, still dropping as the pack voltage increases.


So, thanks for doing the experiment Kingfish--it made my experiment much easier!

Pack charged perfectly to correct terminal voltage, and the charger shut off like the other one does.

On page 2 of the manual I posted is a graph of the output 'steps' of current / voltage.

Ah--I'd forgotten about that. THough that graph shows a flat current output, and it is definitely not that--it is a falling curve as voltage rises, so they are probably only showing the "steps" that the charger can go thru to reach full charge.

I wonder if the other two pots (TR and BR in Kingfish's post) are for changing the points at which it begins the change from one step to another?

Hi@all,

I bought at ebay a second HP8204L3 Charger for using at my office. I opened the original Charger from my BH NEO Cross bike and the other one from Ebay.
Both have different potentiometer. Maybe the Chargers have different Revisions, the BH NEO Cross charger is newer.

See..

HP8204L Diamant Zouma Charger from a 2009


HP8204L BH Neo Cross Charger from 2013


Compare Potentiometer Inside... the BH NEO CROSS Charger only have 2 potentiometers..


good question about howto config the second charger same like the BH NEO Cross Charger...

Sorry to cut into this thread but I've got this charger and can't figure out how to slide the board out of the aluminum case.

It stopped working.

I took the end plates off and am able to determine that a component is unsoldered from the board.

But I can't slide the board out. It seems loose and can slide back and forth but it feels like there is some sort of stop at each end.

Any ideas?

I've got this charger and it's easy to take the ends off.

But how to slide the board out?

I can see that a component has come unsoldered so I need to get the board out.

The board slides easy but it hits hard stops in either direction I slide it.

Any ideas?

Hello iA -

This is an old thread for sure.

I just happened to have that charger right next to me for a completely different use. I took the bezels off both ends to evaluate, and I concur - the PCB is firmly emplaced. The unit appears to be a one-way construction with no plan to service it.

In the post above yours, the lower picture shows an aluminum heat sink on the right side. I think that might be screwed in place. If you are willing to sacrifice the label to find flathead screws (the end of which is poking out on the right side there) I bet the assembly would slide out nicely.

I’m not going to do that to mine so you are on your own pal :wink:
Cheerios, KF