My first breakdown !

[BossBob]

You know what they say .... you pay a quid, you get a quids worth

So, on a steep and very rough main road, clattering downhill as fast as it would go I hit a bump (one of many actually) and the power light died instantly, fortunately within 500m of my work.

Open the controller, check fuses and joints --- all Ok
Open the Battery and I found the eyelet crimped onto the negative sheared at the screw. Flimsy to say the least, but at least it was a simple fix ....... fit a great big sturdy eyelet and a washer to clamp it onto the very small terminal.

Sorted .........

But I had kinda hoped for more than 3 months

As I have now had the battery open I know they are "D" type .... 20 off in a simple configuration, and must be 8AH rated

What is presently the highest rated "D" cell?
And, what would you feel is the "best value" cell getting as close to the highest rating as reasonable?

TY

Rab

 

[Footie]

Commiserations BossBob on your miss-hap.
Funny but I was just raising the point about damage to batteries from road impacts in another thread.
Glad you were able to sort it out
.

 

[Ian]

9 Ah is a typical rating for a D size NiMh cell, there are larger ones, some claimed to be 11Ah but they are untried in bike applications. Manufacturers (But not me ) are tending to regard NiMh as obsolete so little new development is taking place these days and consequently capacities are not increasing.

Most regard Lithium as the future. however I just keep recharging my NiMh batteries, the oldest which has outlived most of the lithium's manufactured at the same time and still retains 100% of its rated capacity.

When I need replacement cells they will most probably come from here.

 

[flecc]

8.5 Ah are the best value ones usually, and also the easiest to obtain very often, large D cell NiMh getting increasingly difficult to source.

The largest I've seen are cheap ones on ebay claimed as 11 Ah, but the discharge rate on those is questionable.

The largest that definitely live up to the claim and also have a high discharge rating are 10 Ah. Batteryspace/Poweriser are one supplier of these, but not the best or easiest of companies to trade with. Ansmann cells from Batteryforce are good quality but expensive, but I've had failures with another expensive make from Eurobatteries.
.

 

[keithhazel]

is it possible to explain this in total laymans terms cos i understand nothing about the technicl side of what you all talk about....if my battery is 37volts..i think..you will know flecc...and it lasts 20 miles...igoring the advancement of technology.....right her right now...if all the little thingies (told you i was layman) that are insie the battery, if ther was twice as many would it then be 74 volt, would that then last 40 miles ?...or wouldit blow the motor up as too much voltage...that being the case is it then not possible to make just he same amount of volts come out as it needs and last twice as long as present one...or a second thought..if i had 2 batteries can they be wired up so that when one is drained the other then starts to be used without the need for getting off and taking out and putting second one in..i have seen a heinzman on e-bay this week that had two batteries , one either side of the panniers, and figured they was both connected up..or maybe im wrong....please please ber in mind with answers.....im THICK !!!!!!!!!!!!! i can plug it in and charge it up.....

 

[frank9755]

Keith,

here's my attempt at answering your questions

is it possible to explain this in total laymans terms cos i understand nothing about the technicl side of what you all talk about....if my battery is 37volts..i think..you will know flecc...and it lasts 20 miles...igoring the advancement of technology.....right her right now...if all the little thingies (told you i was layman) that are insie the battery, if ther was twice as many would it then be 74 volt

Yes, if they were in series

, would that then last 40 miles ?...

No

or wouldit blow the motor up as too much voltage...

No, it would more likely blow the controller, but if it didn't, yes it would blow the motor

that being the case is it then not possible to make just he same amount of volts come out as it needs and last twice as long as present one...

What you need in your battery to make it go further is more amps, not volts. More volts make it go faster, amps increase the range

or a second thought..if i had 2 batteries can they be wired up so that when one is drained the other then starts to be used without the need for getting off and taking out and putting second one in..

Yes. There is a thread here that talks about this. You would need a type of connector called a Schottky diode. But that is the way to go if you want to get two batteries to double your range. Next best of course is to get off after 20 miles or so and swap them over - avoiding the need for any electronics and getting a well earned rest into the bargain!

i have seen a heinzman on e-bay this week that had two batteries , one either side of the panniers, and figured they was both connected up..or maybe im wrong....

No, you're right

please please ber in mind with answers.....im THICK !!!!!!!!!!!!! i can plug it in and charge it up.....

They are good questions!

 

[keithhazel]

thanks frank, some reading to check up on and thinking to do.
keith

 

[Ian]

Keith, the little thingies in the battery are cells and twice as many would indeed double the voltage which would make the bike go faster but not necessarily further.

The factor that is needed for range is battery capacity rather than voltage, this is measured in ampere-hours, amp/hours or Ah, all being the same thing.

Under a given set of conditions the motor will draw a given current measured in amps, for example that may be 5 amps at 10 mph on a level road.
If the battery has a capacity of 10Ah it will supply 10 amps for 1 hour, or in the case of the above example 5 amps for 2 hours (5 amps x 2 hours = 10Ah), and 2 hours at 10 mph is a range of 20 miles.

We could connect another identical battery in parallel with the existing one (Although for technical reasons it's not recommended). which means the two positive terminals are connected directly together as are the two negative terminals. In this case the current of 5 amps would be equally split between the two batteries meaning each would supply 2.5 amps, and given the capacity of 10 Ah would now last for 4 hours giving a range of 40 miles (and possibly a sore backside).

The above is somewhat simplified but hopefully illustrates the principals. There are ways to safely connect 2 or more batteries in parallel but the simplest way of increasing the range is simply to carry a spare battery and swap when exhausted, something I sometimes do.

 

[keithhazel]

i supose after 20 miles i can get off and swap if i have to... ..but thanks ian for your help..totally wasted as the first sign of technical stuff and the dreaded "ah"..and i got a migrane.. ...lol..just kidding..."possibly"... suppose i could increase my distance by doing some pedal assist too...lol....