I’ve stupidly let the battery go flat on SF V4 SP2. It appears as though the official trickle charger died at some point over the winter. I’ve bought a new charger and plugged it in but I’m not getting a ‘charging indicator light’. Any ideas on next steps?
I think I read Lithium batteries don’t handle deep discharge (< 10v) very well… They also don’t like cold temperatures. Did you measure the battery voltage ? It might simply be a case of « waking it up », using electricity draws (lights, etc.)
IMO, too much “I know a mate who has done this” on the internet for what has the potential to blow up in your face. Pretty sure the SP2 will be a lithium iron phosphate unit with a BMS which is probably the least likely to fail catastrophically. I have been advised not to “jump” a LiPo but it has been claimed, a LiPo can be encouraged to wake up after the BMS has turned it off by a brief jump from a 12V lead acid chemistry battery. If it were me, I’d buy new and take the hit. Andy
agree, and depending how old the flat battery is, you can possibly save it at your leisure - i can't remember the details but remember that there is a "kickstart" procedure described on here somewhere. @chrisw will shed more light i would think.
Lithium batteries frighten me. If you are going to do this, then do it in the open. The issue is the internal Battery Monitoring System (BMS). The BMS needs some voltage to function. Fully discharged lithium battery = no BMS = no ability to charge. Watch this video. A fully charged lead acid battery, some jump leads and a suitable battery charger should get things charging.
This subject has been discussed a number of times on the forum, including the safety aspects, as a search will no doubt show. The links below might provide additional information: https://www.ducatiforum.co.uk/threads/lithium-battery.102924/ https://www.ducatiforum.co.uk/threads/battery-replacement-suggestions.62276/ . Hope it helps. Tom.
I’ve just got back from the annual training course and we did a module on batteries, part of which covered charging and recovery. We were told that a lithium that falls below 8v is basically scrap. You’ve basically got a failed or shorted cell scenario. Recharging them, by whatever means, can be dangerous, but that rarely stops us having a go I have in the past recovered them using the jump start, but they rarely last or perform that well. If in doubt, bin it and replace. The consequences of failure are far worse than a lead acid type.
Just my waffle worth. I was told by a fork lift engineer a long time ago not to constantly charge batteries. It does not charge the battery 100 per cent. Does worse. There are different chargers for different batteries. Gel battery does not like high amp charge or jump starting .Lead acid keep it topped up with fluid, therefore high maintenance. AGM happy medium. Lithium when cooked produces it's own oxygen, therefore recirculating fire. If you want to put your bike/car off the road over winter disconnect the battery. Optimers/ trickle chargers I have little faith in.
Along the years, I actually came to believe that batteries need (adapted) maintenance. So I have been using trickle chargers on my batteries (Gel, Li-Ion and LiFePO4) since 2015 and haven’t had to replace one since. The big Optima Red on my Mustang is 12 years old and still kicking butts when reviving the 5,7 liters V8. That changed my life, from when I wasn’t doing this and swapping batteries every 5-ish years, usually after being stranded out away from home… And having multiple vehicles, it’s quite a budget improvement, really.
My 2p - on a modern Li battery, the BMS is designed to shut off the battery before cell damage occurs, so if there is a small drain current (alarm etc) it will stop current flowing to the ancillary system before any battery damage occurs after that, they are pretty good at holding charge over time, but it can vary of battery quality and storage conditions. To come out of safe mode, it needs a nudge to wake up and allow a charge. The problem is that plug and play soft slow chargers sometimes don’t provide the kick is usually the issue and can’t kick a battery hard enough for the bms to come out of safe mode. You could try a 12v battery, but if you are serious about recovering batteries and charging them safely, some dedicated kit is invaluable (see pic - mine are a couple of years old now, but current tech is no different) as you can safely kick /charge /discharge cycle them etc. With the potential consequential damage possible from a problem with the battery on your bike, I would work on it away from the bike, but the often heard scaremongering from the uninformed but opinionated is usually misplaced with current tech. The batteries are robust but don’t like certain conditions but with a quality battery and charger, you would have to try quite hard to have a problem these days.
Charger in action, so you can see the info and control from kit of this type. This is charging a battery we use on the 900ss track bike when we run total loss ignition (no starter, no tf gear, no sprag clutch, no flywheel or any of the gubbins, practically no loom, all replaced by a 1/2 kg Li-Po. The speed it revved and returned to idle was pure race bike on an otherwise bog standard engine - lovely! ) - reading this thread reminded me to top it up, as it’s been over a year since I last did.
Interesting, you are using a lithium battery designed for RC models in your race bike. A nice repurposing. Your set up does differ from an actual 12v lithium motorcycle battery. Some may not realise that the second lead out of the battery to the charger (the one with a white connector) is a balance connector that allows the battery charger to perform the function of a BMS. As I said lithium batteries frighten me, I reference that to experimenting with dumb recycled lithium cells on a solar/wind project (due to the cost of purpose made lithium batteries). Fortunately done in the open air.
I let my Shorai die I put my lithium suitable Noco charger on it and it didn't work. I read on tinternet to charge for 10mins on normal battery mode then switch back to Lithium. Did that and it charged. Still going strong. Maybe I was lucky and didn't get a big bang
It would be unusual if a battery with a BMS became unstable with a normal small (1-2 amp) 12v regular charger (delivering 14-15 volts). However, if it is a smart charger, sometimes they will go into error immediately and not do anything. Using a 12v lead acid battery wired directly to a Li cell has a couple of potential issues - first, it will not reliably get a Lithium battery out of BMS safe as it will typically only deliver up to 12.5 volts even when fully charged, and Li batteries typically need / receive 15 - 16 volts under charge. Second, if it’s a high amp battery, and it is feeding into a discharged Li battery, it could feed far more than the battery can take, far too quickly, and rupture the internal battery structure which could lead to a runaway, which you really can’t stop as you can’t take the energy away to stall it, and you can’t starve it as it doesn’t need atmospheric oxygen to propagate the reaction, so you put it in the garden and let the kids ooh and ahh at the smoke / fireworks display.
