What happens when the battery dies?

[peterhsd1]

I just received my Ezee Sprint two days ago. It has the Nimh battery. I rode about 10 miles over the past two days on one charge. On the way home from work today it started cutting out and then stopped running altogether. After a few minutes of pedalling power would come up for about 30 seconds and then die again. Luckily, I was only a mile from home.

The funny thing is the battery indicator on the handlebar was green but would go to yellow under partial throttle and then red under full throttle. I noticed when I got home the red light on the battery was flashing. First it was four or five and then I thought six which would indicate a throttle fault (brand new bike!).

I'm wondering if the cutting out is just the battery needing a charge or if there is something wrong with the throttle control. The bike should go more than 10 miles but the manual said the first few cycles will be short. It is on the charger now.

My first electric bike. Loved it when it was working .... 19-20 effortless mph (here in the US) but hope this isn't going to be a problematic machine.

Pieter

 

[Ian]

It sounds like you may have a bad contact, possibly in the throttle wiring Pieter. The battery indicator turning yellow and red when using power is perfectly normal behaviour resulting from limitations in the the way that the battery can be measured. It does not indicate a battery problem. and will be even more noticeable at low temperatures.

Possible places for poor contacts are the connector in the wire to the throttle and the larger connector hidden behind the bottom bracket, only accessible with the bike inverted. Quite often problems can be solved simply by un-pluging and re-pluging these connectors, they are however sheathed in shrink tube which will have to be cut away and replaced, ditto with the cable ties.

It is also worth removing the battery and checking the bronze contacts recessed into its base and the corresponding pins on the bike. Any small burn marks on the metal would indicate a poor contact here. Also check the battery fuse for tightness.

As the bike is new it would be advisable to speak to a dealer before doing anything too drastic.

 

[jimmyengland1000]

I think it is possible that the battery needs charging, rather than a contact being loose. I had a Heinzmann bike with a NiMH battery, brand-new, and it did exactly the same thing. The charge level indicator would come on under throttle when the battery was low. Left for a few minutes, it would provide a burst of speed and then die again.

Ni-MH batteries need 'conditioning' and this, in my opinion, is one of their disadvantages. They need to be completely discharged between charging cycles and, unlike a Li-Ion battery, do not benefit from 'top-up' charges. Also, they are quite heavy compared to Li-Ion.

I was able to inccrease the mileage on my battery to about 13 miles... not a great deal. The motor was 500W though and, because it was a throttle-only system (as opposed to pedelec), I did use the throttle more than I would usually. Even so, I wasn't too impressed with the mileage!

One other thing... on my Heinzmann battery, the level indicators (5 red LED's) were quite inaccurate. They would show two LED's which then suddenly both disappeared and the battery was then flat, so hardly much warning.

I sold my bike because I wasn't happy with the range and I did find that having to fully discharge the battery between charges was problematic. It meant setting out on a journey with a semi-flat battery, or running the bike off the ground until the battery was discharged.

Let us know how you get on..... also, if he doesn't see this thread, ask member FLECC.... he will almost certainly have some valuable input....

 

[Ian]

They need to be completely discharged between charging cycles and, unlike a Li-Ion battery, do not benefit from 'top-up' charges

Not true for nickel metal hydride, this was more true of nickel cadmium but applies far less to NiMh which benefit from a complete discharge only once in a while. I have 2 Ezee bikes and 3 NiMh batteries between them, the oldest still at full capacity despite being over 2 years, 3 bikes and several hundred charge cycles old, it gets a full discharge only every couple of months and often longer when I forget.

 

[jimmyengland1000]

Not true for nickel metal hydride, this was more true of nickel cadmium but applies far less to NiMh which benefit from a complete discharge only once in a while. I have 2 Ezee bikes and 3 NiMh batteries between them, the oldest still at full capacity despite being over 2 years, 3 bikes and several hundred charge cycles old, it gets a full discharge only every couple of months and often longer when I forget.

Really? Doesn't a brand-new battery need to be discharged completely for the first 5 charge cycles though?? I thought I read that here somewhere...

 

[flecc]

First two to four charges and discharges are best complete ones to gain near full capacity quickly, but thereafter just once in a while is enough, say one in twenty charges. It's not critical though.

Due to cell availability, the very latest NiMh batteries from eZee are slightly lower capacity, 8.5 Ah instead of 9 Ah. It would be best to check the connections as Ian has said, but if a throttle fault, it's best referred to the dealer.

The red indication coming on frequently is normal as Ian has said. I use two eZee models with NiMh and the meters on those live in the red much of the time in my hilly area.
.

 

[peterhsd1]

Turns out it was the battery. I charged it up last night and it ran great all day. I went about 10 miles today, we'll see how long it holds the chare this time. I guess the battery is conditioning, seemed stronger all day.

I'll do a full review in a few weeks when I've broken it in fully.

 

[jimmyengland1000]

I'll do a full review in a few weeks when I've broken it in fully.

That would be good. I'd be interested to see how much you can increase the range.