• For the battery, get LiFePO4 (a.k.a LFP). The benefit of getting LFP is, it's a drop in replacement. The voltage profile is very much similar with your old lead acid, so no need to concern about voltage compatibility.
  
• For the charger, IF you want to re-use your old charger, make absolutely sure your old charger maximum voltage does not exceed 14V per battery (I don't know how many batteries in series for your old system. So, if it's 24V system, make sure the charger don't exceed 28V). This is probably the hardest criteria to meet, so very likely you'll need to buy a new charger specific for your LFP.
  
• Don't discharge your LFP completely. Unlike lead acid, you need to monitor your usage and stop using it when it's close to 'empty'. I myself use V2 Cycle Analyst Info Page to monitor my usage.
  
• Size. How much size tolerance can you accept in your battery frame? The new battery will be slightly off (not much) compared to your old battery. Since LFP will be lighter than your lead acid, no other concern here (you won't be missing the extra weight right?).
  

Quote:These companies know next to nothing about LiFePO4 and are simply taking cheap Chinese LFP batteries, slapping stickers on them and reselling them to unsuspecting buyers who believe the pure rubbish that it is safe to charge a LiFePO4 battery at 14.6V or regular lead acid levels.. Why? Because these companies have not a clue about interpreting the Chinglish instructions on the battery to begin with. They need engineers on their staff who actually understand LFP and not just a room full of marketers trying to interpret Chinglish.

(16-04-18, 03:47 PM)bigfootpete link Wrote: Just got a new Lithium battery, as I was sick of the AGM ones failing after a year.

I thought they had sent me an empty box it's so light! See attached pic.

Even holding it, it feels like the bottom section is empty.

Let's hope this one keeps its charge.

(16-04-18, 06:52 PM)bigfootpete link Wrote: Hmmm, have alternators on bikes changed that much?
I'm checking with a mate who has built his own electric bike and will let you know what he thinks.

(17-04-18, 01:27 PM)bigfootpete link Wrote:

• Heard back from my battery mad friend, he wasn't 100% sure about lithium batteries.
  
• But he did say that they should not be overcharged or left to go flat.
  
• He also said that the bike will not check what voltage the battery is at so will just charge while you ride it until you stop.
  
• So sounds like the possibility to overcharge will always be present...
  

• If the battery were a normal Lithium-Polymer (LiPo) like you get in phones, I would be 100% against. But its a different type Lithium iron Phosphate (LiFePho4) so I still think more online research and talking to reputable companies based in the UK maybe usefull.
  
• Yup,  as I read from the link I posted above.
  
• Yer, thats the biggest issue - hence my suggestion of finding a way to interface between the old skewl charging system on the bike and the battery with an intelligent one - assuming that can be done.
  
• yes and no, a lot of this LiFePo4 batteries have over-current and over-voltage protection built it (see here), we just need more information.
  

(17-04-18, 09:06 PM)b1k3rdude link Wrote: Something else I have noticed about the battery yu bought, LiFePho4 has way more energy capacity in the same phyiscal space as a LeadAcid, so I think your getting short changed. That battery should be more than the 14Ah, at a guess something like 20Ah -

And while going through the list of Yt vids from the link I posted above I found one saying what I have been saying, you can not drop a LiFePho4 battery into a bike with a charging circuit design for LeadAcid -

- http://www.youtube.com/watch?v=7odOzf2Q0X4

(17-04-18, 09:45 PM)bigfootpete link Wrote: Thanks for the links, I'll do a bit more research to see what I can find out. You'd think the website selling these would have more info rather than just lumping these in with all the other lead acid ones saying it's a direct replacement.

• One of my questions got answered which was how will the batter be charged on the bike as you ride without getting damaged, and that is that reputable battery have an inbuilt Battery managment system (BMS). If it dosen't have this then you will haver to remove the battery often and charge on a mains charger, but even if it does have a BMS you will have to periodically remove the battery and charge off the external charger to balance the cells - if yours does NOT have a BMS then send it back RIGHT now for a full refund.
  

(17-04-18, 09:48 PM)b1k3rdude link Wrote: [quote author=bigfootpete link=topic=24021.msg278580#msg278580 date=1523997908]Thanks for the links, I'll do a bit more research to see what I can find out. You'd think the website selling these would have more info rather than just lumping these in with all the other lead acid ones saying it's a direct replacement.

• One of my questions got answered which was how will the batter be charged on the bike as you ride without getting damaged, and that is that reputable battery have an inbuilt Battery managment system (BMS). If it dosen't have this then you will haver to remove the battery often and charge on a mains charger, but even if it does have a BMS you will have to periodically remove the battery and charge off the external charger to balance the cells - if yours does NOT have a BMS then send it back RIGHT now for a full refund.
  

(17-04-18, 10:01 PM)bigfootpete link Wrote:

• I don't ride very often these days, so in winter the drain from the alarm flattens the battery in a week - even just with the immobilizer on.
  
• I don't have any power to the garage so can't have a trickle charger attached.
  
• I even tried disconnecting the battery but it still went flat.
  

• Same here, untill I got a motobat. So far I have not been touching the Fazer a month between uses and its started every time.
  
• Er atleast you have a garage, how far is it from the house..? if too far then as suggested below, get a solar charge planted on the roof.
  
• Cheap leadacid will do that, that what the optimate and chargers like that are for.
  

(22-04-18, 07:48 AM)ptolemyx link Wrote:

• My research has led me to the conclusion that you can use a Lithium battery in an ordinany modern motorcycle. That's why I've got Lithium on my Fazer, Hayabusa and B-King all without any problems. Provided your regulator is in good condition, i.e. max charging voltage 14.4v
  
• Get a Lithium battery charger though and fully charge the battery before installation and only use it again if the battery voltage gets below 12v on the bike,
  
• which should only happen if you've got poorly fitted electrical accessories,
  
• BTW the fully charged voltage of a Lithium battery is 13.2v. The only caveat to this is a Lithium battery voltage will drop quicker than lead-acid if you have starting problems and need to crank the starter for longer than normal.
  

• Which make/model of battery have you fitted to those bikes, does said battery have a built in BMS (Battery management system)
  
• These chargers like the batteries aint cheap.
  
• in what context, what do you mean by poorly fitted. Fyi any pro fitted alarm, in standby mode will do this. And said situation is made worse for riders whoe dont have a garage or a nearby power source.
  
• I would say no, a lot of vid's of riders doing comparisons have show the lithium will turn over the engine for longer before the voltage drops than a lead acid.