Battery care?

This week I'm trialing cycling to and from work.This is the battery i use

 

https://eclipsebikes.com/product_info.php?products_id=177

 

My commute is 15 mile each way.Which means charging my battery twice a day.At night i charge it while i sleep, once its charged its swiches its self off.

 

Am i harming the battery doing this ?

 

Thanks

15 miles it should to both journeys on one charge.

 

Some will say yes and come out with various theories and even cutting and pasting other people's theories, but I say no because the BMS once it detects full charge simply shuts down an doesn't allow any more current to flow.

Also the charger heat out put lessens dramatically as the current decreases.

 

For charging you are better to do so whilst a wake rather then a sleep for piece of mind though I don't always. If you have time charge to about 3.9/3.95v per cell in the p.m. then finish the charge a.m. before going to work.

Got no chance of doing it on one charge,I have 415 metres of elevation.I try to use pas 2 on the not to hilly bits.Its just to see if i can do it.Even though its an ebike its still hard work.As long as im not doing the battery any harm.

I charge mine overnight using a cheapo mechanical timer (One of the 24hr ones with a big dial and tab like thingys)

I just set it to turn off after 6 hours as this is how long it takes to charge the battery (including an hour for BMS rebalancing)

15 miles it should to both journeys on one charge.

 

Some will say yes and come out with various theories and even cutting and pasting other people's theories, but I say no because the BMS once it detects full charge simply shuts down an doesn't allow any more current to flow.

Also the charger heat out put lessens dramatically as the current decreases.

 

For charging you are better to do so whilst a wake rather then a sleep for piece of mind though I don't always. If you have time charge to about 3.9/3.95v per cell in the p.m. then finish the charge a.m. before going to work.

Do you have a setup that you can adjust to cutoff at 3.9v or do you just keep checking with multimeter?

Gooseman,i dont check anything.I do own a multimeter though.I wouldn't know where to begin checking it.The charger i use is a umini 58.8v 2 amp.Can i buy a charger with adjustable cut off limits.

Gooseman,i dont check anything.I do own a multimeter though.I wouldn't know where to begin checking it.The charger i use is a umini 58.8v 2 amp.Can i buy a charger with adjustable cut off limits.

Sorry that's what i was asking nealh how he did it.

Do you have a setup that you can adjust to cutoff at 3.9v or do you just keep checking with multimeter?

It would be a nightmare to do that IMHO, even though that has some good points.

The easy way is to try and get used to how long the charge needs to be, and set a mechanical timer, for that time, to completely shut off power to the charger, as someone here has already pointed out. Cheap and accurate.

I actually have rewired quite a few such cheap mains timers, so that the tiny synchronous motor, not only shuts off the charger completely from the mains (really good!) when the timer switches, but it shuts itself off as well.

Such timers only cost a few pounds in a shop or off ebay, and last years.

If you buy one, make sure that the screws are NOT safety screws, that need special tools to open. You may need to drill them out and replace with new screws.

A good BMS (no easy or practical way to find out for certain what you actually have, good or not so!) does not need the charger power to balance the battery, because if it did, the charging LED would simply stay red and not go green.

The owner will never know, without opening the battery up and testing certain functions as they occurr, if it is charging or balancing is taking place!!

Once the charger LED has gone green, then for all intents and purposes, the charger is not supplying any current, at the most a few milli-amps, therefore not charging.

But if the charger is left connected for long periods, especially with a battery not maybe quite so new anymore, the battery will drop charging once full, and restart again from time to time, usually without the owner even noticing, as an older battery will not hold the charge as well as it did when new.

This can be a safety problem, if you are asleep and in an extreme case, the battery catches fire, for example, as they are difficult to extinguish!

Many have completely misunderstood just how a BMS and the charger work together.....in the fine detail are important actions, only guessed at by many!

For full details, one needs a good electric/electronic workshop (expensive) and the time and the full knowledge as to how to use them (years of study!).

Most e-bikers seem to not even own a volt meter....at least the ones who visit here, and the first good advice they get from someone is to go and buy one!

Andy

52v at 17.5ah is some 880wh, that's huge for 30 miles and 415m of elevation. It should easily be doable.

Do you have a setup that you can adjust to cutoff at 3.9v or do you just keep checking with multimeter?

 

Just use a meter or an inline watt meter to check progress, after a while one know approx. how long to charge to get to about 3.9v. I 'm not annal about it any where between 38.5 - 39.5 does for me then I top up to 4.1v per cell group.

52v at 17.5ah is some 880wh, that's huge for 30 miles and 415m of elevation. It should easily be doable.

I agree, I have a 36V 375W battery and I get 30+ miles out of it riding around Bristol's hills