SLA battery testing ?

[Jethro_uk]

SWMBO uses a little power scooter for supermarket shopping. It's an Aquasoothe and it has a maxi-battery pack taking 2 12V SLA batteries. E.g.

HSC12-12-18-1167

I bought a pair last June. Fitted them, and coupled them up to the intelligent charger.

Scooter probably gets about 1Km use a week. I tend to bring the battery in and charge it, leaving it on charge until next use.

We've now noticed the battery life has fallen dramatically to the extent of almost giving up after 800, 900m (stated range should be 4-5 miles).

Not being that blessed with test equipment (multimeter), are there any simple checks I can make ?

[Weatherlawyer]

Half a mile is crap. Get them tested at a couple of battery shops. If they were lead batteries they don't last nearly as long as modern stuff but are a lot safer -especially if the scooter is made by Boeing.

There are a number of you tubes showing how to restore old batteries if the plates have not warped. It is merely a problem of solving the lead sulphat e that builds up on them. If you decide to buy new ones check out what deep cycle ones are available or if you can make batteries for a diesel fit. (p utting the wheels and a seat and steering wheel on a lorry battery would be the best way to go for the price, I think.)

22 quid a pop doesn't sound much but how much was the scooter and how often will you be forced to buy throw away packs like that?

Standard and Heavy Duty Battery Packs Available

Travel Lite has two types of battery pack available, a standard pack and a heavy duty pack.

e.html

Would you believe nobody advertises lorry batteries online?

[meow2222]

Those are the wrong batteries. You need ones designed for mobility or golf buggy use. They're much more robust.

NT

[tony sayer]

Give these people a call next time they know all about batteries they do a very wide range!...

[Ian Jackson]

In message , Jethro_uk writes

Check if you've a spare tenner - and if so, treat yourself to a £10 multimeter? See:

[snot]

Yes, agreed. They are the wrong battery type. They are designed for relativity low current discharge cycles. Grand for alarms but not for deep discharge type applications. You need proper deep-discharge electric vehicle batteries

at 4 times the cost - each!

[meow2222]

what should the op do with it?

NT

[Ian Jackson]

Measure the battery voltage when charging, when it has been fully charged - and left to stand for a while, when it is on load etc?

The multimeter will also come in handy for all sorts of other household measurements. It will be £10 well spent.

[Bill Wright]

1. They are not meant for deep discharge, so you have buggered them. Don't believe any bollocks about resurrecting them; it doesn't work. Save yourself the hassle and throw them away and buy some golf buggy type, deep discharge batteries. You only need SLA if you are taking the buggy on a plane, by the way. Otherwise any sort of Lead Acid is OK.
2. Cheap:
3. These are the ones I use. They are very good:
4. Testing. To test a battery's capacity you need to discharge it at a realistic rate. The capacity varies greatly with the discharge rate. A good rate is 5A. Buy three 21W 12V single filament reversing light bulbs. Connect them in parallel to the battery. A nominal 12Ah battery should keep the lamps bright for about 90 mins. Often one battery will lose a cell after a lot of use, but the other will be OK. The lamps will show up the difference, but change both batteries. It's no good to use a new one and an old one.

It is good to get a multimeter though. But spend £40, not £10. If you get one that reads upto 10A DC you can check that the charger is working properly. Often the little charger supplied with the buggy is actually the weak link.

1. The buggy. Check that everything is working freely and is lubricated. For instance if the swivels on the front wheels are stiff (I'm guessing you're using a little rearwheel steer machine) this will greatly reduce range. Obviously the front wheels themselves should turn freely. Lithium grease is good. The wheels come off easy and you can grease the bearings. Some machines have a means of oiling the two little gearboxes at the back. If the lights are filament types change them for LED.
2. The driver Put the driver on a diet.

1. The surface. A carpet will reduce range by 50%!

Bill

[harryagain]

Sounds like your batteries are knackered There are no simple checks for a battery performance check..

The commonest one is to subject the battery to a heavy load and check the voltage.

A proper test involves completely discharging and charging a battery and comparing the voltage throughout the process to a manufacturers chart.

A multimeter will tell you nothing. Batteries for traction are "deep discharge " batteries. Make sure this is what you get. Automotive batteries won't last long, they don't like total discharge. This might be what you have.

There are various ineffictive ways to temporarily revive duff batteries. A lot of buggering about for little benefit.

If you want some nobrain entertainment, here are lots of US hillbillys on youtube f****g about with tractor batteries trying to get two days more life out of shagged batteries.

[Ian Jackson]

In message , harryagain writes

But don't use a multimeter, as it will "tell you nothing" (see below).

But don't use a multimeter, as it will "tell you nothing" (see below).

You see, I told you so!

The problem is, if you don't have even a cheap multimeter, what are you going to use to measure the voltage with?

[Jethro_uk]

Ah !

Tx - Yuasa - brand I've used for my UPS :)

Tx - again

Charger is a 3rd party jobbie. Looks sound enough, but I may research further

No lights. It's a lightweight AquaSoothe with everything mounted on a front tiller. Will check for grease/oil, but I'm sure it's sealed

Will *you* tell her ;). Seriously, driver is 10st - 63Kg - so not that much of a chompalot

Good point. The scooter is kept in the car and mainly used in supermarket shopping. Although it has "off-roaded" when we went to a stately home. Managed about 2 miles last November on these batteries (which may explain something :) )

[Bill Wright]

If you use the Camden type and some others the discharge characteristic is different to what you might expect. The buggy will say the batteries are a bit low after a disappointingly short run, but actually what seems to happen is that the battery voltage drops a bit more steeply in the first part of the discharge period, but then it holds up after that. So the bug will say the battery is half discharged quite early but in fact will keep going for ages before the reading drops further. Also, after a rest the battery meter will start off much higher and will hold up quite well.

They vary so much. The better ones switch to a maintenance charge (a very slow but constant charge) when the battery is fully charged. If you get a meter let us know and someone here will tell you the correct voltages etc.

The range should be about 4 or 5 miles assuming a smooth surface and not too much climbing. We have a similar machine and it will do a four miles outdoor run on a tarmac path that climbs about 75ft overall.

Bill

[Bill Wright]

Some sealed types will not perform as you might expect if subject to heavy discharge. The best test is at a discharge rate similar to the intended use; in this case about 5A.

Apart from

1. Testing that the battery is accepting a charge at a reasonable rate
2. Testing that the charger is capable of providing the stated charge rate, and does not exceed the battery's' maximum safe charge rate
3. Testing that the charger has the correct no load voltage
4. Testing that the charger switches to a maintenance charge (where appropriate)
5. Testing the power consumption of the machine under various conditions

6 Testing for battery drain when the machine is not in use

Apart from that, what did multimeters ever do for us?

Bill

[Dave Plowman (News)]

I have a decent modern tester made by ACT. About the size of a small DVM. Puts a short duration heavy load on the battery and computes the actual capacity. It's very good and you can rely on the results. Although of course all it usually confirms is what I already knew - the battery is toast. I'd not bother testing it if it worked ok. ;-) But is ideal for an unknown one.

I'd assume any decent battery place would have similar.

[meow2222]

The one I maintain uses 2x 12v 12Ah batts and barely manages a mile with new batteries. The handbook claims 10 miles!

NT

[Martin Brown]

They are unfortunately the wrong sort intended for float charging on mains to cover minor outages in alarms with a low to moderate current.

You need a lead acid battery designed for an electric vehicle and the mechanical and electrical abuse that goes with that vibration and high current deep discharge application. Lesser batteries will fail. eg

Unnecessary - they are shot. You will need new ones.

Regards, Martin Brown

[Bill Wright]

There's something wrong there. Both with the one mile range and the ten mile claim!

Bill

[harryagain]

That is the device you need. Draws sixty or seventy amps.

[harryagain]

All done with a special bit of kit that can discharge the battery at a predetermined rate. Big resistors able to dissipate the heat It has it's own instrumentation. And the cheap multimeters are not continously rated (esp for amps)and won't come anywhere near the current drain/time demand.

Most garages have a simple resistor device that carries/draws around sixty amps and measures the voltage. But it can only be used for a few seconds or it will overheat/possibly damage the battery.