Various battery question

[scootntootn]

Hi guys,

I haven't needed the scooter for a while. Not entirely sure of the current pair of batteries, so thinking again about changes.

I have two 12v18Ah. SLA. It's a size constraint.

I have an old fashioned charger. A slow one. Nobody ever addressed what happens if I charge continually (on float) with the batteries installed in an old fashioned scooter made before float.

I have an out of use 8Ah modern charger. Could I use it? Either through the scooter or separately if I do some rewiring. Getting hold of the components can be tricky. Might need to switch to different contacts. I did extensive research on that last time.

I watched a video on combining Lifepo4 and lead for a sailboat solar system. He said the critical part was combining the two, so I should probably keep them together permanently if I do that. Do I charge continually the lead or the Lifepo4 batteries? He had a solar system, so that question wasn't fully addressed. What would be the ideal size in Ah? I'm thinking it should be lower than the SLA and probably two of them attached in parallell.

My thinking is that the gauge on the scooter will reflect the voltage of the SLA batteries, so I don't really need to monitor the voltage of the Lifepo4. By the time I lose a bar, those will be depleted, so I really need to watch the bars.

[Burgerman]

I dont know where to start here. So many questions, and so little information.

First show me a picture of your chargers and the chargers connection. And a link to the scooter.

[scootntootn]

There's a photo of the contacts here. The scooter is in my sig. The newer charger is the standard type provided for bigger scooters in my country. The scooter it was used with had 35Ah batteries. The old one has a jack plug, the newer has the three poled plug also used for microphones.

viewtopic.php?f=2&t=8837#wrap

Other photos will have to wait until next time I go to the garage.

[woodygb]

One of these, charged via a 3 Pin XLR?
https://blastking.com/product/3-pin-mal ... ed-cn16bg/

[scootntootn]

That's the one. The battery contacts are not XLR, but the 8Ah charger is.

It's such a comfortable scooter, for a small one.

I was just looking at the Hobby King Zippo 8400 Lifepo4 a while ago. Interesting option.

[scootntootn]

This is the battery connectors. You can take the contacts out so the scooter doesn't draw current.
https://no.rs-online.com/web/p/wire-hou ... s/8215421/

[scootntootn]

I tested the batteries today. I had charged it maybe a week ago and not severed the contacts. I drove it non stop at top speed for maybe 700 meters before I lost one bar. I can probably make do with these batteries for a while if I drive at slow speed and rest it now and then, unless I need to drive for hours.

By the time I absolutely need new batteries, maybe I've figured out the lithium battery addition.

[Burgerman]

I tested the batteries today.

Thers ONLY ONE WAY to do that. Fully charge with the CORRECT ALGO and not a powerchair charger. And measure Ah removed using say the PL8 charger on a full discharge cycle and compare that to a manufacturers specification for that specific battery. Anything else you may do is not informative or factual but is a personal testiminial in uncontrolled conditions with no means of knowing what is really happening.

I had charged it maybe a week ago and not severed the contacts.

Not sure what that means. Disconnected the battery? Charged it with what and using what charge algorythm. Is the charger any actual good? If the battery is small. And still connected to the chair for a week then you may be testing a battery thats 30% discharged or more. Or less... Depending on the current draw of the switched off chair. And the natural self discharged rate of the battery.

I drove it non stop at top speed for maybe 700 meters before I lost one bar.

That tels you absolutely nothing. You cannot determine state of charge with any voltage based battery meter like that. It may continue to drop "bars" or may recover after a couple of miles... Its almost random and depends od a huge bunch of factors.

I can probably make do with these batteries for a while if I drive at slow speed and rest it now and then, unless I need to drive for hours.

You cant know. Unless you actually drive it till it stops. And when you do that its still a guide. The problem may be that the scooter battery may be badly charged and partly sulfated. Ot that the battery too small for the job by design. To make it portable. And it may be that your battery gauge is all nonsense! As they all are.
By the time I absolutely need new batteries, maybe I've figured out the lithium battery addition.

[scootntootn]

It's different from new batteries behavior. I needed to see how it behaved. Maybe I can't objectively know. But I've driven this thing for a number of years, and I know how it behaves with fresh batteries.

I'm pretty sure I either need to give up on the scooter or change something drastically. The old fashioned kind of charging with that charger isn't a good way to do it when I don't use it enough and leave it unused for long periods of time, even leaving the country for more than two months.

[Burgerman]

Its not got big enough batteries for doing what you want.

If you want to keep a lead based battery healthy and as new when stored you MUST hold it at a low float value of 27V or 13.5V per battery indefinitely.

Or charge then every 2 weeks for 16 hours. With a charger that has the CORRECT charge/float algo and voltages.

[ex-Gooserider]

Note that if you MUST leave the scooter for extended periods w/o charging, the batteries will be happier if they are charged and then COMPLETELY disconnected from the scooter... The controller will still draw a small amount of power even when turned off, and that will add up to kill the batteries faster over time...

Another option if you don't want to leave the charger on all the time but can have it connected is to have a lamp timer set to give it a boost periodically.

ex-Gooserider