Battery question

50Twuncle

dogmaryxx wrote: »

https://www.amazon.co.uk/Ring-Automotive-RBA4-Voltmeter-Clips/dp/B00311BB3U

Thats just a voltmeter - I need to put the batteries under load !

Heedtheadvice

You still have several options especially if you are good with electrical diy. I suggest you still need to diagnose if it is a battery (one, other or both) or some other problem! Not very MSE to just buy new ones!



What about the suggestion of checking all connections? At batteries, between batteries along to motors especially as far as the charge monitoring circuit.


If you have a voltmeter check each battery individually and the connections between them on load. You have one already: scooter with you on it going up hill!!
Or more reliably, with batteries removed in your 'workshop', make a load 1ohm 100watt resistor such https://www.amazon.co.uk/KingNew-Aluminum-Power-Resistor-Resistance/dp/B07C7FQJZ2/ref=sr_1_5?adgrpid=79128826220&gclid=EAIaIQobChMIrL3YhYr85gIVS7DtCh1hngDXEAAYAiAAEgIfG_D_BwE&hvadid=383740350372&hvdev=t&hvlocphy=9046992&hvnetw=g&hvpos=1t2&hvqmt=b&hvrand=15131884992557578009&hvtargid=kwd-296938643936&hydadcr=25977_1931223&keywords=1+ohm+100w+resistor&qid=1578764098&sr=8-5
(not a recommendation plenty out there at a variety of prices/deliver times) make sure there is a 10amp fuse in line for safety, connect voltmeter accross load. Do not do in a flammable atmosphere in case of sparks!
Edit: also best if you put a switch in circuit too!

Presumption here you do have the competence to do this safely. If not do not do it. It will be dangerous if a battery is short circuited and even worse if you connect them together incorrectly :eek::eek::eek:
Further presumption is that the scoots charge indicator is not measuring at each battery's terminals and that your charger is performing a full charge!!

50Twuncle

Thank you all for your advice...

forgotmyname

You dont need a 24v tester test each battery on its own off the scooter.

6amp charger but what does it actually put out? I was given an old steel cased 12Amp charger, after 1amp the voltage plummets to less than 11v.

that

typed this earlier but the forum would not accept it

50Twuncle wrote: »

Charger is rated at 5 amps
It takes a good 6 hours to charge after a 2 mile journey and it is used on average once a fortnight in the summer but probably every month in the winter !
The battery meter - shows 100% when we leave but drops rapidly when put under any load to 2 or 3 bars (into the red) - it recovers when going downhill (regeneratve ??) but only in the short-term - the moment I go uphill again - it drops back down again !
I had the scooter serviced last summer and on load testing - they told me that the batteries were fine....

it could also be the combined weight of you and the scooter are too much, and the motor has to work harder.

Doubt it is regenerative. Fairly sure gravity pulls it down hill so the motor does less work so needs less current. If current is flowing back into the battery the Ammeter should show current flowing the other way.

Also in winter, the cold makes the batteries less effective.

These are the highlight fot those types of deep charge batteries
https://www.atbatt.com/amstron-ap-12220ev-12v-22ah-sealed-lead-acid-battery-r-terminal/
"They use high quality alloys and advance technology which makes them have more than 300 cycle life by 100% D.O.D and excellent quick-charge acceptance ability."

https://www.victronenergy.com/batteries/gel-and-agm-batteries
VRLA AGM: design life 7-10 years
VRLA GEL: design life 12 years
VRLA GEL 2 Volt cells: design life 20 years

https://www.victronenergy.com/batteries/gel-and-agm-batteries#downloads
A truly innovative battery
The AGM Super Cycle batteries are the result of recent battery electrochemistry developments.
The paste of the positive plates is less sensitive to softening, even in case of repeated 100% discharge of the battery, and new
additives to the electrolyte reduce sulfation in case of deep discharge.
Exceptional 100% depth of discharge (DoD) performance
Tests have shown that the Super Cycle battery does withstand at least three hundred 100% DoD cycles.
The tests consist of a daily discharge to 10,8V with I = 0,2C₂₀, followed by approximately two hours rest in discharged condition,
and then a recharge with I = 0,2C₂₀.
The two hours rest period in discharged condition will damage most batteries within 100 cycles, but not the Super Cycle battery.
We recommend the Super Cycle battery for applications where an occasional discharge to 100% DoD, or frequent discharge to 60-
80% DoD is expected.

≥ 300 cycles @ 100% DoD (discharge to 10,8V with I = 0,2C₂₀, followed by approximately two hours rest in discharged condition,
and then a recharge with I = 0,2C₂₀)
≥ 700 cycles @ 60% DoD (discharge during three hours with I = 0,2C₂₀, immediately followed by recharge at I = 0,2C₂₀)
≥ 1000 cycles @ 40% DoD (discharge during two hours with I = 0,2C₂₀, immediately followed by recharge at I = 0,2C₂₀)

http://www.nrgpowersystems.com/product/LSLC22-12--LSLC22-12%20(12V%2022Ah)%20Lucas%20Standby%20&%20Cyclic%20VRLA%20'AGM'%20%20Rechargeable%20Battery/
18 Hole Battery: 20-22Ah, Suited to light use (once a week), flat/short course, light bag, Dry conditions
27 Hole Battery: 24-26Ah, Suited to light use (twice a week), undulating/short-medium course, light/medium bag, Dry/Damp conditions
36 Ho
le Battery: 28-34Ah, Suited to regular use, full bag, all conditions.

Again, "The two hours rest period in discharged condition will damage most batteries within 100 cycles", you need to charge those batteries immediately after use, and don't get the battery to go down to 10,8V .

You do not need a load tester. an ammeter and volt meter should be fine. Think a 10A dc multimeter will work too. If there is a short, the fuse should blow

that

If you can, Li-ion seems to be the way to go and offer more power at lower temperature than lead. Looking on ebay at the bigger 20Ah batteries (rather than cells), companies recommend that you do not connect the batteries in series, and i am not sure why, but possibly due to current flowing through the built in protection circuit?

https://www.12vmonster.com/blogs/product-questions/li-on-vs-lead-acid-deep-cycle

https://batteryuniversity.com/learn/article/absorbent_glass_mat_agm

https://batteryuniversity.com/learn/article/building_a_lithium_ion_pack

If you found a suitable holder, the 18650 cell would probably be the diy way to go, as it is mass produced.

This one is fairly close in voltage 29.2v , 40Ah, £313, perhaps a bit pricy, charger probably extra, but 100% DOD @ 25oC. Assuming: Charge – 1C (50Amp) Constant current followed by 4.1V constant voltage charge.5500 cycles (to 80% of initial capacity), but apparently 0vr time cheaper per Watt than you currently are paying, excluding the unknown charger cost?
https://www.ebay.co.uk/itm/Yuasa-LEV40-Lithium-Battery-29v-MODULE-Outlander-PHEV-Powerwall/293093015317?

Then you have these https://www.ebay.co.uk/itm/PS-30-POWERLITE-UK-LITHIUM-ION-HIGH-PERFORMANCE-DRY-BATTERY-ROAD-RACE-KIT-CAR/302818899978 which are bit pricey

I would be asking questions before purchasing though.

50Twuncle

that wrote: »

If you can, Li-ion seems to be the way to go and offer more power at lower temperature than lead. Looking on ebay at the bigger 20Ah batteries (rather than cells), companies recommend that you do not connect the batteries in series, and i am not sure why, but possibly due to current flowing through the built in protection circuit?

https://www.12vmonster.com/blogs/product-questions/li-on-vs-lead-acid-deep-cycle

https://batteryuniversity.com/learn/article/absorbent_glass_mat_agm

https://batteryuniversity.com/learn/article/building_a_lithium_ion_pack

If you found a suitable holder, the 18650 cell would probably be the diy way to go, as it is mass produced.

This one is fairly close in voltage 29.2v , 40Ah, £313, perhaps a bit pricy, charger probably extra, but 100% DOD @ 25oC. Assuming: Charge – 1C (50Amp) Constant current followed by 4.1V constant voltage charge.5500 cycles (to 80% of initial capacity), but apparently 0vr time cheaper per Watt than you currently are paying, excluding the unknown charger cost?
https://www.ebay.co.uk/itm/Yuasa-LEV40-Lithium-Battery-29v-MODULE-Outlander-PHEV-Powerwall/293093015317?

Then you have these https://www.ebay.co.uk/itm/PS-30-POWERLITE-UK-LITHIUM-ION-HIGH-PERFORMANCE-DRY-BATTERY-ROAD-RACE-KIT-CAR/302818899978 which are bit pricey

I would be asking questions before purchasing though.

Thanks but that is overkill - I very rarely go more than a couple of miles - and the cost is prohibitive
I will most likely end up replacing like with like - albeit slightly larger in capacity
No idea whether a LiIion battery would even fit in the (removable) battery case
Thanks anyway

forgotmyname

I have a fair few LiPo batteries and one of my larger packs is a pair of 4aH 18v (8Ah x18v) units in one homemade case. When charging I do one at a time and balance charge them.

One cell now drops voltage between charges and the case is starting to puff. Accident waiting to happen.

If charged at the correct voltage and at a low rate SLA batteries are fairly safe.

The 8 cell pack mentioned above (post #16) is actually 33.6v when fully charged.


Powerlite Ion battery in post#16 ..2nd link is closer to whats required, but lifespan in the intended application? And a new charger would be required.

that

forgotmyname wrote: »

I have a fair few LiPo batteries and one of my larger packs is a pair of 4aH 18v (8Ah x18v) units in one homemade case. When charging I do one at a time and balance charge them.

One cell now drops voltage between charges and the case is starting to puff. Accident waiting to happen.

Apparently these cells can also short circuit, and will drain all the other cells, so they put a fuse in there. Not sure if the fuse is part of the battery pack circuit, or cell? Think it is more part of the circuit though as some say the fuse can be reset? The words schottky diode and reverse current did go through my mind if connected in parallel.

I have no idea how electric car manufacturers keep their cells charged, but Tesla has had an explosion and some burnouts

50Twuncle

OK I have found a local supplier for these batteries @ £108 for 2 - inc VAT !
I understand that VAT can be reclaimed post purchase - since they are part and parcel of a mobility scooter ?

Or should they be VAT free in the initial purchase ?