NIMH-batteries - Second life project..?

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Vectrix99
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NIMH-batteries - Second life project..?

- Leaf conversion left me with close to 100 NIMH cells. Range was down to 25-30 Km, but at least some of them should be useable. - But for what..?
If someone need them for Vectrix, I can donate. - But guess most of you are quite far from Norway.
But is there any other good use..? Have been thinking about solar power on a hut, but are they suitable for that..?
Some other kind of electric vehicle..?

Any advice would be good :)

Meridiaan
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Re: NIMH-batteries - Second life project..?

Maybe you can use them for a small boat, solarpowered?

elevatorguy
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Re: NIMH-batteries - Second life project..?

I sorted through 200 or so that I had and am using the 130 good cells in series parallel configuration for solar batteries. They power my storage building lighting from an inverter. So far so good, I plan on adding more to increase capacity in the future.

Vectrix99
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Re: NIMH-batteries - Second life project..?

Maybe you can use them for a small boat, solarpowered?

Good Ide. - Have been thinking of electric scooter and so on, but then i have the Vectrix.. In fact my father in law has a boat with an electric outboard. Gasoline engines are not allowed on those small lakes. So boat is possible if i have the right charger, and do seal them properly. - Should be lighter than the car battery he uses now.

Vectrix99
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Re: NIMH-batteries - Second life project..?

I sorted through 200 or so that I had and am using the 130 good cells in series parallel configuration for solar batteries. They power my storage building lighting from an inverter. So far so good, I plan on adding more to increase capacity in the future.

Thanks, nice to know, if I can charge them from solar power it would be good for the hut. As to my understanding charging NIMH with low current can be a little complicated(?). Would be nice to know what kind of charger you do use, voltage and so on.

LeftieBiker
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Re: NIMH-batteries - Second life project..?

The good thing about a solar application is that, except maybe in extreme Winter storm situations, there will be very regular charging of the cells. NiMH batteries have proven so problematic in large part because of their high self-discharge rate, so any application where they are charged almost daily should be better. The other thing to consider is keeping them in the 20%-80% "sweet zone" of state of charge...

Oh, wait... are you high enough in latitude to have weeks or months with no sun? If so, NEVER MIND! ;-)

Vectrix99
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Re: NIMH-batteries - Second life project..?

Good thinking about latitude :)
The "polar night" only occur north of the "polar circle, latitude 66 north. Here at 62 we have daylight for 5-6 hours a day in winter, and 18-19 in summer.. - But the hut is not so much used in winter, so solar power do work, if batteries are not to big.
Maybe I should use a large "NIMH" battery generally, but still use the old gel battery in winter. Or I could use like half of the NIMH-battery.
Have not managed to find a solar charger for NIMH. The existing charger is for "LED acid" or "gel" batteries. Think it can deliver like 14 Volts. Wonder if I could use it for like 12 NIMH cells as well?

elevatorguy
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Re: NIMH-batteries - Second life project..?
I sorted through 200 or so that I had and am using the 130 good cells in series parallel configuration for solar batteries. They power my storage building lighting from an inverter. So far so good, I plan on adding more to increase capacity in the future.

Thanks, nice to know, if I can charge them from solar power it would be good for the hut. As to my understanding charging NIMH with low current can be a little complicated(?). Would be nice to know what kind of charger you do use, voltage and so on.

My original deep cycle lead acid battery failed so I used the NIMH 9 series cells 4 parallel blocks. My charger is a solar charge controller connected to 2 60w panels.
I figured the batteries were just sitting so I put them in service, they stay at 14.1 fully charged. If I run all the lights on the inverter the draw is 18 amps.
They probably live a better life than suffering the vectrix charging profile.

Vectrix99
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Re: NIMH-batteries - Second life project..?

Thanks, Elevatorguy.
I have decided to do the same. Was planning to use 10 cells in each block, but good to know that 9 is good. 9 cells will be fully charged.
10 should have a longer lifetime, but I am not sure how much charge they would get..

elevatorguy
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Re: NIMH-batteries - Second life project..?

Thanks, Elevatorguy.
I have decided to do the same. Was planning to use 10 cells in each block, but good to know that 9 is good. 9 cells will be fully charged.
10 should have a longer lifetime, but I am not sure how much charge they would get..

Vectrix99, I made an error! not sure where my head was at, but I used a block of 9 and added one for 10. 10 will be better as 9 would overcharge and heat with a standard solar charger.
Sorry about any confusion, I must be getting old..

R
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Re: NIMH-batteries - Second life project..?

Assuming the laird charging parameters are correct, 147V before EQ phase/102 cells= 1.441V per cell
charging curve For 12v lead-gel battery:
Bateria_curva_de_carga.png

13,5V is recomended charge for PB gel.
but Flooded lead batteries can reach 14,8v
1.44x9=12,96V
1.44x10=14,40V
1.44x11=15,84V
With 9 in series the cells will be overcharged.
10s Cells would be a nice match, if charge parameters can be customized to avoid overcharging
11s Cells would not charge to 100%, but avoids any potential damage due to overcharge.

elevatorguy
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Re: NIMH-batteries - Second life project..?

R,
I made a correction to what I had stated in my previous post. I am using 10 cells, not 9 as incorrectly stated.
My lead acid battery charged to 13.87, the NIMH charges to 14.1 to 14.25. This gives each cell about 1.4 v

Vectrix99
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Re: NIMH-batteries - Second life project..?

Thanks for correction, and lots of good infos, - also to R.

My solar charger has the selection bethween Lead or Gel, it is now set to Gel.
Have to investigate voltages, or just go there and measure a sunny day.
The Vectrix battery can give like 9 packs with 10 or even 11 cells.
I believe charge current is small for each of the 9 packs, that might give some protection to.
I might as well build packs of 11, that is easier than adding them later. If 11 is to much I could just bypass one cell if needed.

Do you see any dangers with paralell packs? - Should I fuse each of them..?

xabi
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Re: NIMH-batteries - Second life project..?

Im looking for some nimh cells for my vectrix. I,ve test the top pack and i,ve find 4 cells with 0v( not explore more yet) so yours are welcome if you wont use them.

Eixerit

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Re: NIMH-batteries - Second life project..?

Do you see any dangers with parallel packs? - Should I fuse each of them..?

Parallel charging of NiMh packs is not recommended.
Check out this thread on Endless-Sphere.com about a NiMh battery pack bursting into flames when two identical packs were charged in parallel.

Check out powerstream.com for more information on parallel charging.

Alan

Vectrix99
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Re: NIMH-batteries - Second life project..?

Im looking for some nimh cells for my vectrix. I,ve test the top pack and i,ve find 4 cells with 0v( not explore more yet) so yours are welcome if you wont use them.

Hi Xabi. I would be happy to help you out. My pack has done about 10 000 km. - It was replaced as guaranty, because of faulty sensors. - Not sure if it was new, because it felt weaker than before. - Last year range was like 30 km. Scooterdiag did show 16 Ah. Have just found a few cells with 0 Volt, most of them have kept 1.3 volts for a long time, but cannot guaranty Ahrs.
So if you want them, where do you live?. - I live in western Norway.
Johan

Vectrix99
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Re: NIMH-batteries - Second life project..?

Do you see any dangers with parallel packs? - Should I fuse each of them..?

Parallel charging of NiMh packs is not recommended.
Check out this thread on Endless-Sphere.com about a NiMh battery pack bursting into flames when two identical packs were charged in parallel.

Check out powerstream.com for more information on parallel charging.

Alan

Thanks for infos Alan, I sure don`t want that to happen..
I wonder if charging at low rate, up to 12 hours sun a day could be ok...? I guess total current is less than 10A, maybe 5.

"Overnight Charging
The cheapest way to charge a nickel metal hydride battery is to charge at C/10 or below (10% of the rated capacity per hour). So a 100 mAH battery would be charged at 10 mA for 15 hours. This method does not require an end-of-charge sensor and ensures a full charge. Modern cells have an oxygen recycling catalyst which prevents damage to the battery on overcharge, but this recycling cannot keep up if the charge rate is over C/10. The minimum voltage you need to get a full charge varies with temperature--at least 1.41 volts per cell at 20 degrees C. Even though continued charging at C/10 does not cause venting, it does warm the battery slightly. To preserve battery life the best practice is to use a timer to prevent overcharging to continue past 13 to 15 hours."

xabi
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Re: NIMH-batteries - Second life project..?

Hi johan, firstable i'm happy for you answer, like you i'm not sure about the operation of each cell included in the pack of my vectrix so it would be great to achive from yours cells and mine a whole pack with guarantees.

Thanks you very much indeep for offering yours cells of course i want them but i'm from Mallorca just next door ;-) i wonder about shipping cost. Could you calculate? of course refund.

thanks in advance

Xabi

Eixerit

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Re: NIMH-batteries - Second life project..?

A total current of 10A shared across the ten parallel strings of cells should not cause overcharge problems at only 1 amp charge rate (C/30) per cell. It would be like trickle charging a single 30Ah cell with a maximum of 1.4 Watts of power.

I think individual fuses for each string of cells would be essential to prevent any serious problems caused by unintentional wiring faults, and they would hopefully prevent nine parallelled strings of ten cells from instantly dumping a huge amount of current into the tenth string of nine cells if one single cell was to fail in a short circuit state.

If diodes were used on each string of cells it would effectively isolate each of the strings, but a shorted out (failed) cell in an isolated circuit would still cause the other cells in that string to be overcharged, but only at the solar panels maximum current output instead of what effectively would be a 270Ah NiMh pack with a current supply capability of at least 2000 Amps wired directly in parallel with it.

The biggest problem with adding diodes is that the charged batteries would then be unable to supply current back to the solar charger for the all important 12v output supply.
Another set of diodes and a separate device (perhaps a second solar charger unit with voltage cutoff to prevent the battery pack from being overdischarged) would then be required to supply the usable output power for 12V lighting etc..

Alan

xabi
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Re: NIMH-batteries - Second life project..?

Hi Johan,

I live in Mallorca and ,yes, i want them but it is depending on the shipping cost.
If you want to find out the cost. More than 200 euros not worth it
Anyway thanks for your offer.

Best Regards
Javier

Eixerit

Vectrix99
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Re: NIMH-batteries - Second life project..?

I sent you a PM :)

Anderson
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Re: NIMH-batteries - Second life project..?

An idea for outdoor or small indoor (like a shed) lighting using only one Vectrix Nimh battery and Solar Cell;

Solar Cell; Use one or more 1.5 volt Solar Cell ( wired in parallel )
E-Bay sells the sealed outdoor type; US $3.10 "2/4*lot 0.65W 1.5V 0-300mA solar cells
For DIY solar panel/DIY cell phone charge". Note without any kind of voltage regulator I would use only one of these.

Light or lights; Single type AA battery ( 1.5 volt ) powered LED flashlight that the battery is removed and the flashlight is wired to the Nimh battery.

This obviously wouldn't provide much lighting so to increase lighting and to avoid the problem of parallel charging multiple Nimh batteries
you would add more modules ( one battery per system of lights and Solar Cell ).

Vectrix99
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Re: NIMH-batteries - Second life project..?

An idea for outdoor or small indoor (like a shed) lighting using only one Vectrix Nimh battery and Solar Cell;

Solar Cell; Use one or more 1.5 volt Solar Cell ( wired in parallel )
E-Bay sells the sealed outdoor type; US $3.10 "2/4*lot 0.65W 1.5V 0-300mA solar cells
For DIY solar panel/DIY cell phone charge". Note without any kind of voltage regulator I would use only one of these.

Light or lights; Single type AA battery ( 1.5 volt ) powered LED flashlight that the battery is removed and the flashlight is wired to the Nimh battery.

This obviously wouldn't provide much lighting so to increase lighting and to avoid the problem of parallel charging multiple Nimh batteries
you would add more modules ( one battery per system of lights and Solar Cell ).

Actually that is a really nice idea. I do have a few locations around, where some light would be useful. (With no electricity)
As you say, 1,2 V would work fine for small lights. I might be interested in some more. - Then I could use 12V, 10 cells in serial. - No danger whatsoever..:)
Will do some eBay-searching. - Just made a deal to donate 1/3 of the battery to a Vectrix, that is also good use :)

Anderson
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Re: NIMH-batteries - Second life project..?

light4.png

I drew this to try to explain what I was thinking of,my idea is to use only one Vectrix Nimh battery so the voltage is never above about 1.2 volts. If you wanted more light in my scheme then you would have to put together another identical group of parts but they would not be electrically connected in any way to the first one.

One problem is the Nimh battery doesn't like to be overcharged so there needs some kind of a charge controller and I can't find anything yet off the shelf that works with this.

Also I own a number of these single cell 1.5 volt AA size battery LED flashlights and they are still fairly bright at about 1 volt.

Vectrix99
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Re: NIMH-batteries - Second life project..?

light4.png

I drew this to try to explain what I was thinking of,my idea is to use only one Vectrix Nimh battery so the voltage is never above about 1.2 volts. If you wanted more light in my scheme then you would have to put together another identical group of parts but they would not be electrically connected in any way to the first one.

One problem is the Nimh battery doesn't like to be overcharged so there needs some kind of a charge controller and I can't find anything yet off the shelf that works with this.

Also I own a number of these single cell 1.5 volt AA size battery LED flashlights and they are still fairly bright at about 1 volt.

This should work, with the right charger. I guess a solar charger for AA batteries, with big enough capacity should work..- They often use NIMH. Found small ones on Ebay. But most often they charge two cells in serial. That could drive two led-lights in serial.

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