As I await my new ebike arrival I have been doing a lot of research on anything ebike related and came across one mention of a "Luna" charger.
I have a EE degree and am trying to learn all I can about battery maintenace. I did a search on the forum here and didn't really come up with much. Probably because I am not using the search properly.
In any event is the Luna charger still considered a valuable asset to ebike battery maintenace?

You want to use the correct charger for your e-bike not a random charger. Luna sells kits and e-motorcycles so if you have one of those use the correct charger for that product from Luna. I would never recommend using a different charger and if the company you purchased from has charger issues, see if you can cancel that order and get your money back. You should not have battery or charger issues that would require a new charger out of the gate because of dangerous conditions (not a warranty issue but they are just not safe chargers)

IMO, the most important aspects of battery maintenance are to maintain the battery at 20% - 80% SOC (state of charge) and don't charge the battery when it's below 50 degrees F. If I'm going on a long ride I charge to 100% before the ride and make sure the battery is charged to 20% minimum after I return (you can use a voltmeter to determine this as there are charts with voltage vs SOC for each battery "type"). Luna chargers are relabeled AFAICT, but OK (I've had my first from them for 10 years and it still functions adequately), but very unlikely to fit your new battery. The last time I looked there were at least seven different connection systems for charger - battery since many companies want theirs to be proprietary. The charger that comes with your bike should be adequate.

Is this the programmable one?

I almost bought one, but then I figured out I could get an ordinary charger with the right specs so that I can charge my battery to 80%. If your goal is long battery life, this, and charging slowly (say 2A current-limit), can really help.

I keep my other charger if I need to top it off to 100%, but I almost never need to.

Thank you all for the information and advice.
I think most of the lower end ebikes, like I am getting, supply a 2a generic charger matched to the voltage rating of the battery.
Charging to 80% then becomes a bit of a choir having to keep an eye on it till the battery voltage reaches the proper range.
This is where a smart charger like the Luna would be very helpful me thinks. The ability to adjust the charging rate down to as low as 1a is also helpful.
I am still researching proper battery management and learning a lot.

That is why I picked up a second charger matched to a slightly lower voltage rating. Figure out the voltage for an 80% charge, and get another $40 charger. Then you just charge to completion.

No need for the choir.

Hi Tom,
Fellow EE here.
Here's the basics of what you need to know re. Li-Ion battery maintenance:

• Try to keep it between 20-80% state of charge usually. It's fine to charge to 100% and discharge to 0% when you need to.
• Do long term storage (> 2 weeks not ridden) at around 50% state of charge
• Use your charger with a outlet timer, along with some basic calculations to do this ↑. You don't need a fancy charger. For example, if your battery is 10 Ah and you ran it down to about 20%, it needs 6 Ah put back into it. If your charger charges at 2 A, that's 3 hours on the charger. I find it usually takes less than calculated, as the battery gauges aren't that accurate.

Doing these things will about triple the life of your battery.

Jeremy,

Thank you for all the suggestions. I was aware of most of them but still wonder if the Luna might have some advantages.
Like being able to use a 1a charge rate for longevity and 2a or more when time was short to ride. The ability charge it to 80% automatically seems like a nice convienence.
I have heard many times do not discharge it to 0%. I am guessing 0% is the shutoff from the BMC not actually 0 voltage.

Yes. The BMS will have a lower cutoff that is on the low side, but should not immediately damage the battery. Sometimes they're adjustable and sometimes they allow questionably low charge points.
There are some charge charts on this page that may be of help:
https://ebikesforum.com/resources/ca.../batteries.12/

The programmable one is from Grin Technologies. Its a cool tool that you can set up for almost ANY battery I only use mine on oddball batteries. Regular chargers are fine for everything else.

-SP

Yeah, sorry, that is the one I was thinking of,

Some of the negative reviews scared me off.

Polaris,

Several posts back you said you just bought a charger with the right specs to charge your 48v battery to 80%.
That comes out to 50v. I have looked but can't seem to find one that has that output.
Any suggestions?

My 52V Luna charger has 80%, 90% and 100% settings and the charging cable has an XT-60 connector, the same as my DIY batteries. The only way to use this with another charging system is to procure a connector from the XT-60 to that battery or splice the correct connector on the charger (it's just two wires). I recommend you use the charger that comes with your bike and use a timer to attain the desired charge level.You have a wide area to aim for.

I had been looking at the Luna charger and liked its features like setting it for 80% and not having to keep any eye on it much of the time.
I also like the ability to use a 1A charging rate for longevity.
Have no issues with connectors as I have a well equipped soldering station.
Have you been pleased with the Luna charger?
Tom

I bought a Luna charger for that specific purpose - to have an easy 80% limit. Unfortunately it did not work with my battery but they were good about a return. Using a 2A charger, I have figured out it takes about half the time I ride to recharge to the level it was before I rode out. So when I do a 2 hour ride, I put it on the charger and set a phone alert for one hour. If I started at 80% then I'm just about at 80% recharged. If you do enough rides you will get a sense of how long it takes. If you have certain rides you repeat, it will be even easier. Once a month I charge to a full charge on the advice of the system manufacturer. If you keep some notes on your ride and charge times, you'll get a feel for it and won't need a cutoff. However, you can use a timer between the plug and your charger if you're not going to be home to shut it off.

Lots of good information to retain mentally and put into practice here. Thank you. I’ve already picked up eBike repair and maintenance manuals.
I’ve subscribed to thread.

Yes, I agree

It is a 52V battery, Sorry.

My Luna charger has been perfect after a couple of years. I checked the *0%, 90% and 100% levels and they matched the chart. Other than that, it charges at 2 per hour which seems fine for longevity.