Looking for someone in AU (preferably) to re-pack an old NiCd (6v) battery pack - Page 1
Forum section: electronics / general

author: Halcyon
author_rank: Unknown
timestamp: January 18, 2023, 11:24:13 am
content: I have an old radio scanner which I'd love to start using again. It's the Uniden UBC3000XLT.My only issue is the battery pack (and the DC jack built-in) is the only source of power to the device.The NiCd cells are long gone, the entire pack was measuring near enough zero volts. I pulled open the pack and it's comprised of a Sanyo "Cadnica" 6 volt, 600 mAh pack (model 5KR-600AE) with a small external circuit board for charging and supplying power to the device itself. The pack is made up of 5x 2/3A size cells. The DC jack also seems a little dicky (not sure if it's a bad solder joint or the jack itself is a bit loose from years of use).I don't have the tools to be able to spot weld a new pack together. I was hoping someone on the forum would be able to assist with re-building this into a usable pack, either using new NiCd cells, or seeing if it can be converted into something with more modern battery technology, but maintaining the original shell. I can send the pack (along with the DC charger, which outputs 12v @ 200mA) to someone who is better equipped and willing to do a small job for me.Of course I'll pay you for materials, your time and shipping (I'm located near Sydney).

author: Zucca
author_rank: Unknown
timestamp: January 18, 2023, 02:53:56 pm
content: Hey Halcyon,I am sure you have done your homework, but in my book I would like to move away from the NiCd horror and jump in something more user friendly like Li-Ion, LiFePo4 orLSD NiMh.Even if you be able to get the NiCd unicorn pack in your hands, it will not last as long as the others chemistries.The (very bad) environmental argument of NiCd is also valid but second to performances issues IMHO.

author: Halcyon
author_rank: Unknown
timestamp: January 18, 2023, 11:16:11 pm
content: Quote from: Zucca on January 18, 2023, 02:53:56 pmHi Zucca,I'd love to switch over to some other, better, more energy dense technology that doesn't suffer from the same issues as NiCd's do, but without the proper tools or knowledge, it's not something I can do at home.If someone can work out a way to do this, using the original shell, then that's great. But I'm assuming it would need an entirely new charging circuit designed and squeezed into the same pack, so this would add complexity and likely cost to the project.

author: Zucca
author_rank: Unknown
timestamp: January 19, 2023, 03:35:52 am
content: Quote from: Halcyon on January 18, 2023, 11:16:11 pmI would love to help, you need a good DC load to understand how the charger works.In other words you need the V/I plot of that charger.Set the DC load to min batt voltage and go all the way up to V batt max, write down the current the charger spits into the battery pack.Ideally you want to know at what high voltage the charger stop to charge, I=0.Once you have some data, I am sure me or other people smarter than me here (EDIT: sorry typo here...) will help further.You do not need to redesign the charger, you could for example let the battery charging up to let's say 60% or 70% (improving even further the battery life), hopefully not waiting ages for it.Probably 60% 2023 battery technology is > 100% NiCd.All speculations of course, we need the data.

author: Halcyon
author_rank: Unknown
timestamp: January 19, 2023, 03:48:33 am
content: Attached are some photos of the circuit board taken with my phone (apologies for the crudity), flipped "Big Clive" style so the components match up.BLK - Device negativeBRN - Device positiveWHT - Battery negativeRED - Battery positiveThis little board is tucked away inside the battery pack itself and the DC plug pack (center-positive, 12VDC, 200mA) plugs into it to both charge the battery pack and power the device.(And yes, that's how this board looked from brand new. No one has "had a go" at it).

author: Zucca
author_rank: Unknown
timestamp: January 19, 2023, 04:10:47 am
content: There is hope! It is not so impossible as you think.Well, so you have 12VDC 200mA going into that horror movie board and then to the batteries NiCd, correct?Let's say we go with Li ion, 4.2 V fully charged 3.6V normal operation.With 3 cells in series you will have a voltage swing from 4.2*3=12.6V full charge - 10.8V normal operation.Just test if with 12.6-10.8V your Uniden UBC3000XLT is happy or not.Also test when the Uniden cuts off, what is his min voltage <12V.Stupid me. all the above is wrong.... eggs on my face.The Sanio 5KR-600AE are 6V 600mAh, that board is just to calm down the 12VDC PSU to charge them. I assume.So the Uniden wants 6VDC....this is the discharge curve of the NiCdso I assume the Uniden get's from the battery 5x1.3=6.5VDC max - 5x1.1V=5.5VDC min...Now if the charger is 12VDC can you check what is the voltage atBLK - Device negativeBRN - Device positivewhen the charger is connected?If the Uniden is happy with 3.8Vx2=7.6V max it would be sooo perfect.Do not forget to measure how much current the device needs to stay alive..... maybe that current will change with the voltage so keep track of it.Ah, reversing eng the manual:QuoteSo 600mAh/5h = 120mA best case current needed by the Uniden.Li ion for portable devices is red carpet! I hope it is possible.

author: Halcyon
author_rank: Unknown
timestamp: January 19, 2023, 05:04:02 am
content: Quote from: Zucca on January 19, 2023, 04:10:47 amThe charger output approx 15 volts open circuit. About 14 volts is coming out of the device pins (without the scanner connected).This is all I'm able to test. I don't have a variable power supply. I'd love to have an electronics lab set up at home, but it would be one of those things I use maybe a few times a year.

author: beanflying
author_rank: Super Contributor
timestamp: January 19, 2023, 05:37:39 am
content: Master Instruments is one of the best goto's in Oz for 'specials'. Not sure of the current availability of NiCads but well worth a go or see what else they can offer.https://www.master-instruments.com.au/category/Nickel_Cadmium_-_NiCd/2308

author: Nusa
author_rank: Super Contributor
timestamp: January 19, 2023, 06:08:09 am
content: I would never recommend using a NiCad charging circuit for lithium-ion. Not safe.In any case, I'd suggest rather than trying to pay someone to fix the battery you have, just order a replacement battery. It'll be WAY cheaper (well, maybe, I dunno what postage will be from your end). I found you an AU ebay listing, but obviously you can search for other sources:https://www.ebay.com.au/itm/162740763896

author: Halcyon
author_rank: Unknown
timestamp: January 19, 2023, 06:12:16 am
content: Quote from: Nusa on January 19, 2023, 06:08:09 amI'll have a look at replacements if a re-pack isn't easily achievable. It's just I'm dubious of some of the stuff on ebay. Their true origin/quality is often unknown.

author: Zucca
author_rank: Unknown
timestamp: January 19, 2023, 01:56:03 pm
content: Quote from: Nusa on January 19, 2023, 06:08:09 amsurely not with that charger... that charger belongs in the electric waste bin.

author: Zucca
author_rank: Unknown
timestamp: January 19, 2023, 02:02:06 pm
content: Quote from: Halcyon on January 19, 2023, 05:04:02 amYou need 2 Li ion in series (2s pack) and you are good to go.Now it is just a space/case problem. You need to find two Li ion cells that will fit nicely in your case.After the above is done,organize a charger for the 2spack and you are in heaven my friend.Slap a 2s BMS in it to be safe...Example rough calculation.Two 18650 2Ah will give you up to 16.5 hours of joy.... why trying to find the NiCd unicorn for up to 5 hours?

author: tunk
author_rank: Super Contributor
timestamp: January 19, 2023, 02:09:52 pm
content: You could look into using one li-po cell, a TP4056/BMS charging board,and a step-up module set to 6V. Any battery indication won't work, andmay not work if the scanner needs a quiet power supply.

author: Zucca
author_rank: Unknown
timestamp: January 19, 2023, 02:19:56 pm
content: Quote from: tunk on January 19, 2023, 02:09:52 pmIMHO not necessary, the Uniden should work with 7.6VDC voltage no problem. No need for a DC DC thing.

author: Zucca
author_rank: Unknown
timestamp: January 19, 2023, 02:22:46 pm
content: Quote from: Halcyon on January 19, 2023, 03:48:33 amTo be 100% sure of the 2s pack compatibility, try to get the schematics on paper of that board. Two diodes, one led, 2 R and one DC plug. With a DMM is not that hard.With the pictures I can only best guess, I can't measure continuity for you.

author: factory
author_rank: Super Contributor
timestamp: January 19, 2023, 07:38:04 pm
content: Wouldn't 2x LiFePo4 in series be better? as they would be closer in voltage to the original NiCd cells.David

author: Zucca
author_rank: Unknown
timestamp: January 19, 2023, 08:47:24 pm
content: yes but less energy density.Since with that charger there is a good chance the device will operate a 7.6V or more I see no point to not go with the Li ion.

author: magic
author_rank: Super Contributor
timestamp: January 19, 2023, 09:09:49 pm
content: It seems that the built-in "charger" is simply a 150Ω resistor. A pretty lousy way of charging anything, but NiCd would be the most tolerant of such abuse. With unprotected Li-ion it's an outright fire risk, but a better charger/BMS could be added as suggested before.It also seems that with the PSU plugged in, the right diode connects device negative to PSU negative. Meanwhile the left diode always connects both device positive and battery positive to PSU positive. So it looks like the device can run on PSU voltage minus two diode drops and it may tolerate two Li-ion cells indeed. It could be a good idea to confirm this with DMM.The PSU jack probably contains an internal switch which bypasses the right diode when the plug is pulled out, connecting device negative straight to battery negative. Positive side is already shorted by PCB metal.editNope, I think I got it wrong. The upper terminal of the DC jack is the negative, the lower terminal is the switch. The device is powered straight from the PSU minus one diode drop on the positive. The right diode is only used maybe for a moment when the DC plug is being pulled out before the switch engages, or when the external PSU is plugged in but dead.Yeah, Zucca is right, just make a proper schematic

author: Zucca
author_rank: Unknown
timestamp: January 19, 2023, 09:12:32 pm
content: Quote from: magic on January 19, 2023, 09:09:49 pmThat's why I wrote aboveQuote from: Zucca on January 19, 2023, 01:56:03 pm

author: Nusa
author_rank: Super Contributor
timestamp: January 19, 2023, 11:37:51 pm
content: Or just rip out the guts and put battery holders for whatever size cells will fit in the right combination. 18650's, Alkaline AA's, whatever. Change batteries as required. For the rechargeables, find a standalone charger for them. A lot of problems just disappear if you separate the charging solution from the device.

author: Halcyon
author_rank: Unknown
timestamp: January 20, 2023, 12:17:59 am
content: Quote from: Zucca on January 19, 2023, 02:02:06 pmI'm limited on space. 18650's won't fit in the original pack. I could squeeze one in on a diagonal but it would be a cell without built-in protection circuitry and it leaves little room for anything else. I want to keep the entire unit as original as possible.I didn't want this to turn into a whole overly-complicated project. It's just an old radio scanner that I use very occasionally (and almost always have the capacity to leave it plugged in). Having a working battery is just a nice-to-have.I figured someone who does this professionally or at least has the right tools, would be able to swap the existing pack out in 15 minutes.Quote from: Nusa on January 19, 2023, 11:37:51 pmPossibly an option, but modifications would need to be made to the pack housing. It's an absolute bastard to get open. It's clipped securely shut on all sides. It took quite a bit of levering and cracking to get the damn thing open initially.I'm thinking at this point I'll just remove the old batteries altogether (or at least disconnect them) for a future day, and just run it off the mains.

author: vk6zgo
author_rank: Super Contributor
timestamp: January 20, 2023, 01:36:53 am
content: Quote from: Halcyon on January 18, 2023, 11:24:13 amI have the very same device, but in my case, it is still "hanging in there".It doesn't have a very long charge life, but it is quite adequate for my usage.The DC jack probably is "dicky"---my one needs "wiggling" till the LED stays on, following which, it charges OK.Although the "usual suspects" will be horrified,I would tend to stick with Nicads, as they obviouslycanwork OK in that setup.Again, I wouldn't be too worried about the perceived need for spotwelding the battery connections.I replaced the Nicads in my Ryobi drill a couple of years back, & there were a number of Youtube videos of people who got good resultswith just soldering the tags together.In my case, unfortunately, & quite unusually, the transformer in the Ryobi charger died.As I was going into hospital for an operation & had a major job in the back yard to complete in limited time, I bought an "El Cheapo Ozito drill & finished the job.I hoped to pick up a Ryobi charger at a local swap meet, rather than build one "from scratch" but with my new "pretend" knee, plus looking after SWMBO, I didn't get round to it, so I have no direct knowledge of the durability of soldered tags on batteries, but since it is hardly a "moonshot" in your application, I doubt you would have any problems.The hard part might be finding the replacement Nicads in the correct size.

author: Zucca
author_rank: Unknown
timestamp: January 20, 2023, 02:20:59 am
content: Quote from: Halcyon on January 20, 2023, 12:17:59 amTell me how much space you have and I will try to get the cells for you. They are also pouch cells, either way I still think it is much easier than what you imagine.

author: beanflying
author_rank: Super Contributor
timestamp: January 20, 2023, 02:52:38 am
content: Just for interest I dropped Master instruments a line and they have 16 NiCad's in stock of thesehttps://www.master-instruments.com.au/products/62025/ICF600AS.htmlfor around $4 AUD each plus whatever the cost of making it into a pack (or buy them as tagged cells and solder yourself) would be.Trickle charging NiCads with a Resistor is still fairly bombproof and away you go for another decade or more.

author: Zucca
author_rank: Unknown
timestamp: January 20, 2023, 02:58:30 am
content: All true and right... could you then build the battery pack for him? I would never do that but it's not mine Uniden.

author: beanflying
author_rank: Super Contributor
timestamp: January 20, 2023, 03:02:11 am
content: Master Instruments have been building packs for decades and they have a head office in Sydney which is 1000km closer to Halcyon than I amOr they also resell through a Business called Battery World which have stores all around the country if that is closer.If it was me I would buy spot welded tagged cells from them and solder them myself.

author: buta
author_rank: Contributor
timestamp: January 20, 2023, 03:40:04 am
content: NiCd batteries can be replaced by Panasonic eneloop nimh battery (I am a eneloop user) which is widely available.https://www.ozbargain.com.au/search/node/panasonic%20eneloop%20nimh%20battery%20type%3AozbdealProperly the same charging circuit will work.It seems you have disassembled the battery pack, can you post some photos that show how the batteries are connected, soldering, spot welding or ...?Edit 01: further search I find this 6V AA packhttps://www.rcmodelaircraft.com.au/ni-mh-eneloop-receiver-5cell-flat-6v-2000mah-jr-hi

author: Zucca
author_rank: Unknown
timestamp: January 20, 2023, 04:03:43 am
content: Yes but then you will torture them with that circus charger IMHO.Still a much much better solution than a horrorible new NiCd pack.

author: Halcyon
author_rank: Unknown
timestamp: January 20, 2023, 04:17:25 am
content: Quote from: vk6zgo on January 20, 2023, 01:36:53 amEvery UBC3000XLT I've used has the same issue. It looks like mine have broken solder joints on the board.

author: beanflying
author_rank: Super Contributor
timestamp: January 20, 2023, 06:13:47 am
content: Quote from: buta on January 20, 2023, 03:40:04 amThe 'only' issue with changing from NiCad to a NiMh option as you can get the same size cells in either is the charging part of it. NiCads more or less were very tolerant of being left on constant low current charge even when nominally full. NiMh by comparison doesn't like that so you would likely need to remove it from the charge system when full or look at changing the board out to something NiMh friendlier.Also be aware that AA's are skinnier and much longer than the 2/3A so it is not just a case of buy consumer grade cells.

author: buta
author_rank: Contributor
timestamp: January 20, 2023, 07:13:25 am
content: Quote from: Halcyon on January 18, 2023, 11:24:13 amI properly miss the above information.Edit 01:RS has 22pcs AU stock of 1200 mAh 2/3A NiMH TAGGED cellshttps://au.rs-online.com/web/p/speciality-size-rechargeable-batteries/0221046

author: Kean
author_rank: Unknown
timestamp: February 01, 2023, 09:33:07 am
content: @Halcyon - if you still need help with this, let me know and I'd be happy to help out. I buy regularly from Master Instruments and I also have a battery welder and related parts for battery pack assembly. I am in Sydney, on the northern outskirts.

author: Halcyon
author_rank: Unknown
timestamp: February 08, 2023, 11:16:18 pm
content: Thank you so much Kean for your kind offer, the pack is on its way to you. Once you've made an assessment and we decide which way to go, feel free to plug your business and post any pictures/information here for those playing along at home.

author: artag
author_rank: Super Contributor
timestamp: February 08, 2023, 11:32:00 pm
content: Whilst pretty useless for Halcyon, if some UK person comes looking at this thread with similar needs, I have foundhttp://www.strikalite.co.uk/pretty good for building packs when I don't want to do it myself.

author: Kean
author_rank: Unknown
timestamp: February 09, 2023, 09:51:48 am
content: Quote from: buta on January 20, 2023, 07:13:25 amLOL, RS can be handy but only if you can deal with their often ridiculous inflated pricing and terribly annoying re-packaging