Battery question

50Twuncle

My 2 year old mobility scooter came with two off lead acid (gel) 18ah batteries which have virtually died - I plan to replace them with identical sized 22ah replacements - for more range
Will the original charger do the job (just taking slightly longer) ?
https://www.mobilitysmart.co.uk/strident-mobility-battery-agm-12v-22ah.html

Also - some advice sought on charging

I simply fully charged the old batteries after every use and then gave them a top-up just before using again - is this going to reduce the life span of the batteries?

Undervalued

50Twuncle wrote: »

My 2 year old mobility scooter came with two off lead acid (gel) 18ah batteries which have virtually died - I plan to replace them with identical sized 22ah replacements - for more range
Will the original charger do the job (just taking slightly longer) ?
https://www.mobilitysmart.co.uk/strident-mobility-battery-agm-12v-22ah.html

Also - some advice sought on charging

I simply fully charged the old batteries after every use and then gave them a top-up just before using again - is this going to reduce the life span of the batteries?

I use one of those 22ah batteries, although for a different purpose.

The same charger should be fine.

Whilst yes it would take longer to fully charge the battery from flat, as it is a bigger capacity, if you only make the same journey taking perhaps 4ah out, then the charging time should be much the same as before.

I assume the charger is one that cuts out when it decides the battery is full? If so then topping up, perhaps unnecessarily, shouldn't do any harm.

that

Yes, replacing like for like if the same technology off lead acid (gel) should work. Obviously they will be heavier too. You may could also be able to get a better charger should one be available?

want something cheaper, possibly with a larger capacity, slightly different terminals, and i am unsure of the mounting for £30-ish cheaper?
https://www.ebay.co.uk/itm/PAIR-12v-12AH-15AH-22AH-33AH-36AH-50AH-55AH-75AH-AGM-MOBILITY-SCOOTER-BATTERIES/123911738023?

or two of the exact same type for also £30-ish cheaper, but similar terminals?
https://www.ebay.co.uk/itm/2-x-12v-10ah-12-15-17-22ah-33-36-40-50-75ah-Mobility-Scooter-AGM-GEL-Batteries/253214770314?

50Twuncle

Undervalued wrote: »

I use one of those 22ah batteries, although for a different purpose.

The same charger should be fine.

Whilst yes it would take longer to fully charge the battery from flat, as it is a bigger capacity, if you only make the same journey taking perhaps 4ah out, then the charging time should be much the same as before.

I assume the charger is one that cuts out when it decides the battery is full? If so then topping up, perhaps unnecessarily, shouldn't do any harm.

I was just wondering how long batteries should last in a little used mobility scooter ??

forgotmyname

Depends how hard its worked and how low its run down and how long its left in a discharged state.

Then the charging speed also affects its lifespan.

How many amps does the scooter draw loaded up on a steep hill? How fast does it charge? (charger A rating?)

Little used, do you charge the battery at least once a month?

50Twuncle

forgotmyname wrote: »

Depends how hard its worked and how low its run down and how long its left in a discharged state.

Then the charging speed also affects its lifespan.

How many amps does the scooter draw loaded up on a steep hill? How fast does it charge? (charger A rating?)

Little used, do you charge the battery at least once a month?

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....

Heedtheadvice

That last response 50Twuncle would suggest that the battefies were ok last summer...but might not be now......or there is another problem such as a bad connection somewhere.


I assume that the low charge on load (red indication ) has only been a fairly recent experience!



Good batteries should only have a small voltage drop between off load and on load conditions. However a similar indication would be given if there was a poor connection between battery and load, early in the circuit with battery monitoring on the load side of any such bad connection. A bad connection has higher resistance and drops a significant voltage making it appear to the monitoring circuit that there is a low charge state when under load.

The result of the bad conbection is very similar to that which would occur in a car that had corroded contacts that had difficulty turning over the engine but would run fine.


The on load test of batteries shows up a similar 'high resistance' problem within the battery.
So, as well as a possible faulty monitoring circuit (suspect if your scooter still drives well!), then you have two likely main causes. Batteries (expensive to sort eh? ) and bad/resistive connection somewhere that ought to be cheap to fix! I would rule out the latter (or get the batteries checked again) before splashing out my cash!

50Twuncle

They claim an 11 mile range from the original batteries from new
I would not trust them to take me 2 miles now

50Twuncle

I am assuming that the scooter runs on 24v (2 off 12v batteries in SERIES ?) – So would need a 24v battery load tester – these are considerably more expensive than 12v ones (which can be purchased for £10) ...

D_M_E

Scooters are notorious for gobbling up battery power when doing uphill traverses.

Think a lot of them say someting like max incline 8 degrees so anything steeper than that will gobble up charge, and your bar indicator will show recovery because less energy is being drawn from the battery, giving them a chance to recover slightly - probably the only energy being drawn is enough to stop the brake workin g plus a small amount to assist gravity going down the slope.

Just make sure the larger batteries will fit in the same space as the old ones.

dogmaryxx

50Twuncle wrote: »

I am assuming that the scooter runs on 24v (2 off 12v batteries in SERIES ?) – So would need a 24v battery load tester – these are considerably more expensive than 12v ones (which can be purchased for £10) ...

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