How to repair a BP100/200 battery base?

kaosun

The above is for BP200 which uses 2X 4100MAH3.7V cells which theoretically can support up to 20 hrs.

serge1996

Since I got this battery from you, with appropriately rewired D-50MkII, it became my favorite player. Works more than 10 hrs off the battery, sounds way better than thru AC-DC power supply. Million Thanks!!! Most highly recommended upgrade, if you ask me.
One question: may I connect this battery to my D-25 (it was not rewired by you)?
Also, can you do the same for Technics SL-XP5? Batt pack is SH-CDB5.
Let me know...

kaosun

serge1996 2016-02-19 12:15
Since I got this battery from you, with appropriately rewired D-50MkII, it became my favorite player ...

D25 can use the modified battery base directly but the D25 cannot charge the battery base.
Also, the unmodified D25 will transfer the battery power back to the battery, so the red LED on the battery will light on unintended.

Yes, of course for the CDB5. It's a good solution for those who can't find the original weird power adapter. You can use an ordinary 9V power adapter to charge the battery, then the battery can power the XP5 for around 10 hrs. I've never modified it so far but I think it'll be OK. One thing is that a step down and reverse power supply will be design to power the XP5 since it uses positive and negative 6V while the battery is single 8V.

serge1996

Great! Actually, I got the whole kit: SL-XP5+Battery+Adapter+LeatherCase. Are you going to rewire SL-XP5 as well, I mean do I have to mail it to you along with the battery?
I am also going to sent Philips your way, along with two (2) RCD2 lasers: hopefully you will be able to revive at least one of them (photos of my third RCD2 is posted somewhere here, it is beyond resurrection)

kaosun

serge1996 2016-02-20 00:13
Great! Actually, I got the whole kit: SL-XP5+Battery+Adapter+LeatherCase. Are you going to rewire SL ...

Sure, send them all to my address.

serge1996

OK, will put all the pieces together and ship next week.

update 02/29/16:
Kaosun, Sorry! I did not have a chance to put all the pieces of Philips together for shipment. Got stuck with a "big" project of restoring my favorite boombox. "big" meaning that all the pieces are so big, once gutted this monster takes all the space on and around my desk. But I am getting there... and, as always, my day job interferes with my hobby...

One question: when you rewired my D-50MkII, by any chance did you check its laser alignment? Now, with your battery it is my best-sounding portable but it is not the best tracker.

kaosun

serge1996 2016-02-21 00:59
Edited by serge1996 at 2016-02-29 16:54

OK, will put all the pieces together and ship next week.

I just modified its charging circuit last time. Since it seems it can read discs flawlessly, I didn't check its laser. I assume its reading is good. Let me know what's wrong with it in detail so I can suggest what we can do to improve it. OK?

serge1996

Got it! I have to check this D-50 again, but if I remember correctly it plays CDs without any glitches, maybe skips once in a while; but it definitely did not like my skip-test CD. Most probably thats just how it is. I wanted to go thru the motions of its calibration as described in the Service Manual, in hope of learning something in the process, plus the technique described is so weird that I want to try it! Did not want to mess with it if its already been calibrated by you.
I am still playing with my new toy: Technics SL-XP5, I LOVE it!!! Million thanks to you for the tip, this player is truly amazing!!! Once done playing I will send it to you for battery rejuvenation. Hopefully your Li-Ion packs will work with this +/-6V config.

Jehr

Hi Kaosun,  I see this is an old thread, but I was curious if you could share how the charge controller works on a D-T10?  I was going to update my batteries on the BP-100 to LiPo.  

My idea is:

7.4V from D-T10 charge controller --> 5V L7805 --> 7.4V Lipo Charger --> 7.4V (8.4V) Battery pack

The L7805 is there as most mini lipo chargers have USB voltage in.  

Will the higher voltages >8V from the battery pack going back into the unit shut down the 7.4V charge controller too early?  Or will it just monitor the voltage and current at the L7805 and keep charging until the Lipo charger shuts down?

I see from the service manual you can tweak the charge voltage as well.  I haven't played around with that yet so I am not sure what the range is there by making the solder changes.  

Any help would be much appreciated.  Thank you.  

kaosun

Jehr replied at 2023-09-18 11:48
Hi Kaosun,  I see this is an old thread, but I was curious if you could share how the charge control ...

Nop, for Li-ion/Lipo battery charging, I use specific Li-ion/Lipo charging IC. What I'm using here is a BQ2057 from TI. It has 3-stage charging design:
1: Conditioning battery if it is drained too low by 0.1C (C is the battery capacity, here is 2200mAH)
2: Constant current charging even the battery voltage rises during charging, the IC output constant 0.2V to maintain 650mAH charging current which takes 3.5hrs to fully charge the battery.
3: When it's fully charged, the IC output a tiny current like 0.1C to perform a trickle charging to compensate the capacity.

There's no 7805 IC in the charging circuit.