# Mobility scooter batteries

Discussion in 'Power Electronics' started by CaptJR, Jul 30, 2013.

1. ### CaptJR

2
0
Jul 29, 2013
My mobility scooter has two 12 volt batteries in series. 24v

I can not get my scooter in the house so I have my batteries brought in so I can charge them. I guess normally the on board 24v charger is used but in the house I use two 12 volt chargers.

I notice when I charge them that the one always takes a lot more time to charge than the other one. My question is.... should I rotate the connectors so that the one that gets the big draw is not the same one all the time?

Also, would it be better to use the on board 24 volt charger?

Thank you,
JR

2. ### john monks

693
2
Mar 9, 2012
Specifically what do you mean by "the big draw" and "rotate the connection"?
I would think that both batteries are in series and therefore both batteries have equal draw. Where am I confused?

3. ### CaptJR

2
0
Jul 29, 2013
I think we are confused in the same way. I thought in 'series' the draw would be equal, but then why would the one always need more charging.

The connects are made in a way that I can tell which battery is which. If I reversed the connectors the other battery would be on the Positive end of the series??

JR

4. ### john monks

693
2
Mar 9, 2012
Where the two batteries are connected together is there another battery that goes somewhere else? If not then I would be inclined to think that one battery is defective. Do you know of anything that uses 12 volts on the scooter? What happens if you simply switch the batteries around?

5. ### Y2KEDDIE

259
15
Sep 23, 2012
Scootter batteries

I would try switching the batteries around to see if the charging rates are different. I't may be the chargers are different, or one is defective. If the batteries are the same and the same condition, they should charge at realitivly the same rate. Once you are sure the batterries are both in the same condition (take them to a service center and have them tested), It would be best to connect them inseries and charge them with a 24 V charger. When charged in series they should equalize, (actually they should be charged at a specific equalizing voltage determined by the battery manufactuer). After they are eaqualized they can be maintained by a float voltage. If you charge them individualy it will be hard to make them equalize, and this can harm the battery.

Always try to charge the batteries the same way you use them.