Newbie - Battery PCB Repair - Component Identification - Page 1
Forum section: electronics / repair

author: Griffo
author_rank: Newbie
timestamp: September 13, 2019, 04:45:09 am
content: Hi all,Long time lurker of the forums and Dave's channel, lots of great info. I now need some help...Recently I started a project of fixing a 2014 Brammo Empulse R motorbike. The battery was having various faults and making the bike unusable for the previous owner. I'm very much a DIY person, love tinkering and love bikes so I thought I would grab it and have a go at repairing it. I narrowed the fault down to a balancing issue. The onboard charger stops charging if it detects one module out of limits, tries to balance the cells by bringing down the high cells then commences charging again. The problem was that the high cell wasn't coming down so the charger refused to charge anymore.The module out of balance was no 1 of 7 and after pulling apart the battery I found out why. The battery has 4 internal heaters that are used for heating (obviously) and also for balancing when commanded to. Due water ingress part of the module's controlling PCB had some corrosion and component damage which has stopped the heaters from working which is why the charger couldn't balance the pack. I've cleaned up the corrosion with some vinegar which seems to have worked. I now need to identify the damaged components and replace them and hopefully get this bike working again.I've attached photos of the stages of me pulling apart the bike for those interested.The bike before dismantlingDisassembled7 battery modulesModule 1Cover removedCorrosion on PCBUnderside of the module showing all the pouch cellsTop of the module with PCB removed. You can see the plates used to connect the pouches in 4p9s config.Underside of the PCBAfter cleaning up the corrosion.edit: fixed up photos

author: Griffo
author_rank: Newbie
timestamp: September 13, 2019, 04:52:58 am
content: Below is a close up of the corrosion area. The components in the red boxes are the ones I've identified as possibly being damaged and I'm trying to identify.I'm learning as I go with this one. I'm open to all hints, tips, recommendations or abuse...Thanks everyone for your help...

author: tautech
author_rank: Super Contributor
timestamp: September 13, 2019, 04:57:10 am
content: Quote from: Griffo on September 13, 2019, 04:45:09 amWelcome to the forum.Nope, not nearly clean enough especially around C62.Warm soapy water then flush with clean water or pop the whole thing in the dishwasher.An old toothbrush can be good for cleaning PCB's.Leave in the sun for a couple of days to properly dry.

author: tautech
author_rank: Super Contributor
timestamp: September 13, 2019, 05:05:29 am
content: Quote from: Griffo on September 13, 2019, 04:52:58 amL1 is an inductor and if it gives a small ohms value reading then it's probably OK.My guess for C74 is a 10uF SMD tantalum and it can be tested with any reasonable DMM.U24 will be the same as all the others in that row and we need the SMD code from from one of them to identify it.Package looks like SOT23-5 and measurements can confirm that.C62 is probably 0.1uF or 0.01uF.

author: fzabkar
author_rank: Super Contributor
timestamp: September 13, 2019, 05:29:13 am
content: The capacitor appears to be a 100uF, 10V, lead free, solid tantalum type made by Vishay/Sprague:https://docs-apac.rs-online.com/webdocs/1682/0900766b8168211c.pdf(page 3)The date code, C7, decodes to July, 2012:http://www.vishay.com/docs/40110/faq.pdfEdit:The "F" appears to denote the 893D or TF3 series. Both have a built-in fuse, while the TF3 has low ESR.https://in.element14.com/vishay/tp3c107k010c0250as/cap-tant-100uf-10v-2312/dp/2629628http://www.farnell.com/datasheets/2050130.pdf

author: fzabkar
author_rank: Super Contributor
timestamp: September 14, 2019, 03:58:58 am
content: I'm guessing that the SOT23-5 ICs are MOSFET gate drivers:https://au.mouser.com/Semiconductors/Power-Management-ICs/Gate-Drivers/_/N-41fcp?P=1z0z33qZ1yzxd6bZ1z0z7pt

author: Griffo
author_rank: Newbie
timestamp: September 22, 2019, 05:18:33 am
content: You guys are legends! Thanks heaps for the info. I've been away with work and haven't had much time to look at it further. I'll have a look at the info provided and try and take same better close ups.I've managed to source some more battery modules from another bike that aren't working. I should be able to grab the components off the PCB of those modules to fix this one.I'll post updates when I get further info. Thanks again!!

author: Korbin Dallas
author_rank: Newbie
timestamp: October 18, 2021, 02:06:45 pm
content: Reviving this thread in hopes of more info on what was found out.I have a similar bike with a charging problemCheers.