Loosing my memory

[Draggin]

     Ive got 1850kms on my 36v 13ah molden gotor.  I rided 17kms one way to work.  So Ive got a hundred and a little bit charges on the gal.  Just the last few days she has died out on the way through the gate or the way up the drive.  I've gotten almost twice that in the summer.  Three times my charger missed the delta v and got pretty hot, maybe 4 hours before I yanked the plug.  At work I'm on station service (not to stable) at the local utility.  I'm thinking that either the batteries are worn out or they have developed a memory from the same run every day.  Do you think a 10 amp boost might liven them up or finish them off?  It sucks when you have to actually pedal.

[Draggin]

   So it would be a shot in the dark for me.....unless I did them indevidually. 

[Dragon Slayer]

Well, without knowing the internal resistance of each battery, yes, doing them in series would be a shot in the dark.

[Mel in HI]

car batteries I am using for my UPS seem to be doing better.

I can't believe you are suggesting to use a CAR battery for a UPS.  Car batteries are designed to give a sudden surge of current over a short period.  UPS batteries are designed to give a lower amount of power over a longer time.  One has solid plates, the other has 'sponge' plates.  Hooking a UPS up to a car battery should kill it over a couple long duration power outages, I have actually seen that result and it was a nasty mess of melted plastic and spilled acid.  

[Draggin]

    The internal resistance.  Is that what they measure when they put that load thing a ma jiggy on my battery at the garage

[Draggin]

     Im wondering if the wind and cooler tempuratures increases the load this signifigantly.  myelectricbike says his batteries lasted three years.  Maybe I'm not loosing my memory just my mind!

[myelectricbike]

     Im wondering if the wind and cooler tempuratures increases the load this signifigantly.  myelectricbike says his batteries lasted three years.  Maybe I'm not loosing my memory just my mind!

Can you quote where I said that? I'm not doubting you but my memory too (like HALs) is beginning to fade.

I think the problem is how most lead acid batteries are remanufactured and called new.

[Mel in HI]

Sorry, I wasn't thinking about small UPS's with short runtime requirements, I guess a car battery might suffice in that case.

Don't forget the effect the temperature will have on the batteries output too. 

[Draggin]

general discussion page 2 second reply. in "battery questions"

[Draggin]

so how long might these batteries last

[Mel in HI]

Even my big 1500 watt UPS will shut things down within 10 minutes of no power. Want more time and the only way to go is by adding external packs according to budget and need.

If your 1500 watt UPS is considered big, then you and I are talking about different critters.  I consider my 5kw UPS to be a small UPS and that has 3 battery units (4 big batteries each) all cabled to the electronics unit.  My big one is about the size of a large walk in closet and we have to change the batteries with a forklift.  I too have 'small' UPS's that I use in the places where they just need to save documents and shut down, but I wouldn't consider the real estate on their desks worth putting an external battery and would question the charger's ability to charge it.

[Mel in HI]

so how long might these batteries last

Why not look up the manufacturers specs on the battery?  I don't know which battery you are using, but some manufacturers actually give some pretty good details on how their batteries will perform under certain loads over time.  Others of course don't give much details.  Who makes your batteries and what model number?

[myelectricbike]

I've used the Wal-Mart $14.95 (currently $20) lawn and garden batters for UPS and they lasted almost a year - far less than the $22.95 (currently $31.95) 12Ah SLA/AGM I've had in service now for nearly 3 years. ...

I was not referring to ebike use unfortunately but only to my 320 watt UPS which came with only a 7Ah SLA/AGM.

[myelectricbike]

Even my big 1500 watt UPS will shut things down within 10 minutes of no power. Want more time and the only way to go is by adding external packs according to budget and need.

If your 1500 watt UPS is considered big, then you and I are talking about different critters.  I consider my 5kw UPS to be a small UPS and that has 3 battery units (4 big batteries each) all cabled to the electronics unit.  My big one is about the size of a large walk in closet and we have to change the batteries with a forklift.  I too have 'small' UPS's that I use in the places where they just need to save documents and shut down, but I wouldn't consider the real estate on their desks worth putting an external battery and would question the charger's ability to charge it.

I'm not talking about large UPS systems designed for buildings since most of these use an entirely different chemistry than lead acid and if not in most cases defer to gas powered generators within a few minutes or even seconds.

[Draggin]

What would your wife do to you if you bought that 12Ah Lifepo4 on ebay.ca for $429.99US?  What do you think mine would do to me?  Do you think that she would believe that Santa gave it to me?  Or maybe just wait till she pays the credit card bill.  I could try, I thought you said it was ok.  No no no it's for the Roomba.  or, it was an accident, I thought it was spellcheck not paypal.