Li Ion Battery Charging Question

[Nust]

Hi guys,

Brand new member to the site but have been browsing it for a while now preparing to do a café project. My question is this. The Anti Gravity Li Ion battery I have is deadish and my current project isn't yet complete. So i'll need to charge it but I know these things are pretty particular about what you can use to do that. Anyone have any idea where I could get an acceptable charger asides from the antigravity ones that are a little expensive?

Thanks in advance for the help guys.

Once this GSXR project is done i'll be starting my 79 cb750k brat and am looking forward to posting something up on it once started.

 

[Sonreir]

Usually, if it's dead, it's dead. You can't really charge LI-ION back up again. You need to keep it charged all the time or the anodes dissolve.

That said, if you're still over 11V, you can sometimes save it. A trickle charger that doesn't exceed 14.5V will usually do the trick, but any charger that doesn't have a desulfate process will also work, provided you keep an eye on things and don't leave it hooked up for more than a couple of hours.

 

[Nust]

That's going to be an awfully expensive situation should that be the case. Its still got some charge just weak and don't want it to get worse. Ive no idea if my standard smart charger has a disulphate process or not, I suppose I can try to look up a manual on the charger again. I'm annoyed that its lost charge at all considering its been sitting almost entirely disconnected less a couple brief mock ups for fitment and has gone low. I thought that was one of the many benefits of these bloody expensive units.

 

[Sonreir]

Yup. That's definitely one of the benefits. LI-ION lose about 2% of their charge per month, just sitting there. That's a lot better than lead acid. For mine, it means no trickle chargers over the 5 months of crappy weather we get here in the PNW.

One of the caveats is a significantly lowered capacity. Having your bike turned (but not running) for even 10 minutes can cause significant drain. Unfortunately, in order to hide this, most manufacturers have chosen to list battery capacity in AhEq (Amp Hour Equivalency) instead of Ah. For instance, Ballistic is fairly honest in their listing of having a four cell battery advertised at 2.3Ah. Antigravity chooses to list their four cell at 6 AhEq. Chances are, the cells in each of these batteries are more or less the same (think comparing Duracell with Energizer, not much in it).

Ah rating is a rough measure of capacity. For a four cell battery, I think 2.3 is a fairly accurate representation. In this case, 2.3 Ah means we can draw 2.3 amps for one hour or we can draw one amp for 2.3 hours before the battery is fully discharged. You can do the math for more or less current and work out the time. A stock headlight on a vintage bike is probably drawing about 2.7A. A high power halogen from a modern machine will be around 4.2A.

Where LI-ION does shine is its ability to quickly push out current. A very small battery can crank a huge engine because it can discharge much more quickly than lead acid. Unfortunately, that does come with costs that aren't measured only in dollars. Whenever possible, try to avoid any sort of testing with your LI-ION. It's for after you get things up and running.

 

[Nust]

Well that's all great info to know. Wish I had know that, I could have run some long leads and used another source of power to test some of the wiring and fitments for the battery and its wires. Unfortunately only a Li ion battery fits in my current setup and even with brief power on it was running an HID headlight ballast on this GSXR. Hopefully its salvageable.

Thanks again for the info.