You credit me with more knowledge about batteries than I actually have Rob!
I did attend a seminar on lithium batteries at my yacht club that was quite informative. People were starting to use them in yachts (for reasons I don't understand) which is why the club organised an expert to come along and give a presentation.
From what I understand, lithium batteries can tolerate a fast charge without damage. That would be the maximum charge rate. The 'standard' charge rate is what you'd use for normal charging if you're not in a hurry to whack some charge into it.
I do recall a couple of other salient points on charging lithium batteries. They are sensitive to over-charging and under-charging (or perhaps better described as over-discharging). You can kill a lithium battery by doing either.
They have a very flat voltage profile which means they'll hold full voltage as they discharge, right up until the last gasp when the voltage drops off sharply. That characteristic creates a couple of hazards you need to be aware of. Firstly, you can't tell the state of charge by measuring the voltage, and secondly, the sudden voltage collapse means you can easily discharge it beyond recovery.
Smart battery chargers for lead acid batteries (that includes AGM and gel type) will apply a 'normal' charge amp rate until the battery reaches full charge (around 12.8V) then will drop down to a fraction of an amp to maintain the battery on trickle charge.
However, that type of charging program won't work for a lithium battery. The thing will charge OK during the normal charge cycle, but the smart lead-acid battery charger isn't quite smart enough for lithium. It can't tell when the lithium battery is fully charged because of the flat voltage profile, so it'll keep charging at the 'normal' rate, and end up over-charging the lithium battery. That's a bad thing, because the only way the battery can absorb more energy is by heating up. That'll fuck the battery. Taken to the extreme, it could explode.
You need a 'very smart' charger to properly charge a lithium battery. That's the type of charging system you install when using lithium batteries in something like a caravan or a photovoltaic array. They're getting quite a lot of use as house batteries in caravans to reduce weight.
The way a full bells and whistles lithium battery monitor works is to discharge the battery until the voltage just starts to drop. That establishes the point of discharge as a datum. Then it goes into charge mode and delivers the correct amount of charge to the battery to bring it up to full charge, then it goes into monitoring mode. Since it can't tell from the voltage when the battery is fully charged, it has to calculate the amount of energy delivered over during charge cycle (volts x amps x time). It also calculates the rate of discharge so it knows at all times what the charge state of the battery is. It has a built in micro-processor to do all that. The only issue is that you need to tell the monitoring system what the capacity of the battery is. So fancy lithium battery systems need a charge controller/monitor that's programmed for the particular battery array that it's connected to.
Of more interest to us is lithium batteries for motor vehicles. Cars and bikes don't have intelligent battery monitoring devices, so a good quality automotive lithium battery will have a battery monitor built in. But it only has a limited capability to protect the battery against excessive discharge or over-charge. The best it can do is modify the output voltage profile to approximate that of a lead acid type, so it'll work with automotive charging systems. But as far as I am aware it can't actually prevent over-charging if you leave it connected to a battery charger for too long.
Some lithium batteries have better protection than others. As an example, I killed an almost new SSB lithium battery by leaving the ignition switch on for a couple of days. It discharged completely and wouldn't recover. I ended up chucking it out, but in hindsight it may have been recoverable if the protection circuit had simply disconnected the battery cells from the terminals (to prevent further discharge). There may have been some way to re-boot the protection circuit.
When buying a lithium battery, it would be sensible to do your homework and find out exactly what it's built in protection circuitry does. Then you'll have a better understanding of how to charge it and what to do if it goes wrong.