Charging Times

[privateer703]

I know this info is on the forum and I was looking around, but I feel like for those looking to buy an Alta an easy to find sticky with the charging times for all 4 configurations would be handy. Now that there are some rapid chargers for a good deal I'm wondering how much improvement I'll get from the standard charger.
While I'm on the topic maybe some battery expert will answer a question I have: Is it better for the batteries to be charged slowly, like say 120V with the standard charger, or is the difference insignificant? I like to tell myself that I'm helping my battery last longer by keeping with the standard charger at 120V.

 

[bluefxstc]

If you are using 120VAC, both chargers will be about the same. This is a limitation of the outlet, not the chargers. In the US, most 120 VAC outlets are 15A, the chargers typically limit the charger to 12-13A or about 1.5kw.

On 240VAC the standard charger is about 2.7kw. I believe the rapid charger on 240VAC is 3.6kw so it is faster than the standard charger so your charge time will be shorter. On some Alta's you do need the proper FW to take advantage of this. Early MX and EX bikes did not take advantage of the additional charge power without the FW upgrade. This is a CAN bus communication issue as the charger only provides the amount of power requested by the bike, and the early bikes didn't request the power available in the rapid charger without the FW upgrade.

In general slow charging is better, but at the rates we are talking I don't think you will notice a battery life difference. Fast charging is normally at rates greater than 1-1.5C (capacity). Even with the fast charger we are only at about 0.6C so it is really not very fast.

 

[bluefxstc]

Just after I posted my post above, I attended an Idaho National Lab (INL) presentation on EV battery charging. INL is part of US Dept of Energy and has been doing a lot of research, as far back as the 80s, on EVs and EV batteries. I don't want to hijack the post, but here are a couple of the slides from that presentation the people might find interesting and are somewhat relevant to the post.

 

[Judaslefourbe]

What I like about wireless charging is OEMs spend a lot of time and effort reducing/shielding against EMI and then we turn around and figure we should blast that shit on 11...

 

[privateer703]

So if my math is correct the rapid charger is only going to be about 24 minutes faster than the standard charger for a full charge.
5.8 Kw / 2.7 Kw = 2.15 * 60 = 129 minutes
5.8 Kw / 3.3 Kw = 1.76 * 60 = 105 minutes
I know this ignores some small inefficiencies and the balancing stage, but should be close enough.