A couple of quick techno battery questions

[eBoy]

Evening, folks!

I have just bought a little meter and would like to know what the voltage reading tells me aboot the state of my battery, which is a 36v 10a.

And also, for longer journeys, would wiring a second battery in parallel with the first one cause any problems? Would a new battery 'balance' up okay with an older battery, and sort of even up?

Many thanks,

Johnny

 

[KirstinS]

Should be 42v hot off charger if healthy and the bms should cutout around 32v but this can vary a bit. They tend to drop to 40v quite quickly then slowly drop down to 36v as you use up the charge. They drop quite fast from around 36v so don't be far from home !

It is easier and safer to have two batteries and simply swap over when first is empty. You can parallel but you need to be sure the ah are the same and the cells perform the same. Or better are same type and age

 

[Deleted member 4366]

Charge the battery. As soon as you can after the light goes green. Tell us what the voltage is snd the type of battery, and I'll tell you if it's Ok.

You can put batteries in parallel, but they must be within 1v of each other when you connect them. Also, you mustn't charge one while they're in parallel. You must disconnect them first.

If you want to leave them permanently connected in parallel, you can, but they need blocking diodes between them.

 

[eBoy]

Thanks D8v and Kirstin. Wwill charge battery tonight and check voltage as soon as I get the green light.Johnny

 

[eBoy]

D8v! I have just checked voltage now the green charging light has come on. It reads 43 volts. the battery is a Phylion battery XH370-10J. 37v 10a. Looking forward to your verdict, ta.

Johnny

 

[Deleted member 4366]

Phylion is a word I didn't want to hear. Their cells behave a bit differently to most. They sometimes measure as healthy cells, but have no capacity. They charge up to 4.2v each, just like healthy cells, then they drop as soon as you put a load on them, and when you take the load off, the voltage bounces back to normal again.

Phylion batteries are not noted for their long life and reliability. I guess that you're measuring yours because it's down on capacity.

To measure the capacity, you need a wattmeter, or you can get a rough idea from the time to charge from empty. Another clue to problems is if you have battery indicator lights on your throttle or display. If they go right down when you open the throttle, the battery has had it.

 

[eBoy]

Thanks, D8ve, for all that low-down. Maybe I've been lucky then, as I've not had any problems with the battery as yet. I did about 20 miles on a trip last week, pedalling a bit as well, and it was still on 4-5 LEDS of its 5 LEDS of power at the end. But I've been using it almost daily for nigh on 4 years now and have been thinking it may be time for a new battery soon, just because of that. I'll stop mithering and just keep on the go! I wonder if Phylion are still being supplied? Many thanks again. Johnny

 

[KirstinS]

4 years out of a phylion ? Daily usage?

You got your money's worth without doubt !

When it is time to replace you'll find technology has moved on you'll get better cells, more capacity, lower weight or a least two of the three. Your bike will likely perform a fair degree better aas a result. Especially on hills where your current battery voltage will sag

What bike do you have? Pictures of battery and bike are helpful for us to provide options for you

Cheers

 

[eBoy]

That's encouraging news, Kirstin, ta! My bike is an eWayfarer from Pro Rider, and it's a super little bike - a folder with with a vertical battery behind the seatpost. Been everywhere with it, and batteRy is stillgoing strong after all this time. Maybe by the time I need a new one, we'll be onto fuel cells that will take us a couple of thousand miles between replenishments. LOL! Johnny