Bounder dies when battery gage gets to 6? Batteries seem ok

[Burgerman]

Again not enough info. So I will guess its their 8A one.
Which has many problems.
https://www.pridemobility.com/pdf/owner ... manual.pdf

NOTE: COMPLETE battery charge is NOT achieved until battery has charged for 15 hours.

It gives a green light after around 4 to 7 hours. Which meansyou can use it. But it IS NOT CHARGED. That takes as it correctly statesaround 15 hours to 20 hours. Why? Because it stops te CV stage too soon. And relies on float to complete the charge. But nobody bothers to wait 15 hours, so they get up and use the chair since it says "green" and done on the charger! This causes rapid sulfation. So insteadof great range and 500 cycles you get a fraction of this.

SPECIFICATIONS:

Output Voltage
AGM
CV DC 29.6V +/- 0.2V
FLOAT 27.3V +/- 0.4V

Somewhere there is a switch on this charger internally or externally or it is programmed one way or another.
This is its AGM voltages. Both a fraction too high for AGM, and simpy miles too high for gel. Be sure you dont use this on gel!


If its configured for gel:

GEL
CV 28.6V +/- 0.2V
FLOAT 26.7V +/- 0.4V

FLOAT is OK aslong as it doesent do that 0.4v too high thing! (not accurate enough) but the CV absorption stage os MUCH too high. It needs to be 28.2 MAX and actually 26.9 ideally if you expect a long service life. And theres an MK chart below showing the effect of overvoltage on MK Gel batteries (all gel batteries actually). And if its above 25C you must reduce that further. See graph.
Or your battery will be increasing in impedance and unable to produce high currents due to gel shrinkage and voids caused by gassing.

[Burgerman]

Pride dont make batteries or chargers, neither do permobil, sunrise etc. They only care that its cheap to them and that it can charge a battery. But all chargers do that even crap ones. What matters is how well. They get away with this because they do not care how long your battery lasts. If it fails they sell more batteries. Mostly they dont see a problem as most users never go more than a mile or so. Many never leave home. Even more sit watching TV or drinking coffee all day. So ON AVERAGE the problem is hidden and so they see few problems.

If however you happen to be the one that actually uses your chair more than this, then its YOU that is the problem as far as they are concerned. You are a small minority of problem users. Lead batteries are simply not adequate for todays heavier and faster powerchairs They were *just* about capable before heavy rehab chairs became common - these are literally double the mass. And before faster chairs became common too. Why is this an issue?
A full rehab seating chair is around DOUBLE the weight. So double the battery Ah gets used up at every speed, at every manoever. Even indoors. That means shorter battery range, by much less than half because you not only need more Ah, but you get much higher voltage drop under loads such as turning or accelerating. And because the faster you discharge the battery the less total power is available. See peukert on the web! So the battery voltage falls way faster than the capacity gets used up.

Also if you have say an 8mph chair it doubles these losses and doubles the Amps needed over a 4mph chair. So now the situation is actuaLly 4x as bad. The same as having batteries 1/4 the physical size and capacity. Having to produce 4x the current (amps) at every manoever no matter how slow you go. Because extra weight+extra speed=4x the power taken from the battery doing everything. Even at slow speeds.

When you are using 4x the Ah every day, that increases the average depth of discharge enormously. Depth of discharge determines cycle life. You get only a handfull of deep discharges. Thousands of shallow ones. So as well as getting way way less overall range, the battery needs MUCH longer to fully recharge than we have in an overnight situation to charge. And this greater discharge level means far, far fewer cycles even if it IS correcty charged. And few are.

So in a faster chair, with a heavy user, and a heavy rehab seating system its lead batteries, no matter how good, or how well they are charged stand much chance of survival. Especially IF you actually USE your chair rather than sitting in frot of the TV. Lead simply cannt cope. Normally. However:

Theres 2 options.
1. Accept this situation. Or retro fit high capacity lithium of around 200Ah.

2. Use the CORRECT charge algorythm for your gel battery, (or AGM battery.) And use the BEST quality battery available regardless of cost and thats very limiting as theres only 3 or 4 of these. And use a seperate Anderson charge connector for a higher Amp charge ability and a PARTIAL TOP UP as often as you get chance during the day as you eat or read email etc (as well as FULL OVERNIGHT charge). This effectively revents deep discharge levels that destroy batteries much faster.
Use say a ZXD charger set carefully to 20 to 25A and to the CORRECT CV setting (GEL 28.2V max, AGM 29.0V) and a termination point of 0.2 or 0.3A for a more complete charge and then 27.0V FLOAT.
This if carefully maintained as a battery charge ideal can mean you get many years. But will never get the sort of range enjoyed by older lighter basic or slower chairs did in the past. Remember weight. And a chairs gearing (its top speed). Both enemy of batteries.

If like most you are looking for a simple answer to "fix" the problem there isnt one.

[Burgerman]

If you have a heavy chair, heavy user, low tyre pressures, less than ideal batteries, crappy charger, high speed package, live near hills, severe programming so it actually responds properly, its cold, or any combination of the above. Then batteries will give bad performance, and short lifespan. And the more of the above you have then the worse it gets.

And the opposite is true.

[Pierro]

Thank you BM, - slowly, very slowly I begin to understand. To be honest, in the past I had never given much thought to rechargeable batteries and charging them correctly. I still don't understand a lot, but some things are now clear to me.

I have this charger for my Adventure A10 and it has some toggle switches. But unfortunately no real information was found about what you can set there.

Maybe someone has a manual?

https://www.ego-elektromobile.de/products/e-go-aura-5

I can't shake the feeling that it sucks.

Pierro

[Burgerman]

Problem is nobody can tell. Theres not enough info to know anything. It may be god, bad, programmable? But if I dont know exactly what it does I cannot know.

At least the pride mobility charger actually has the information that tells us its crap! Details matter.

[Burgerman]

Heres another one. This MAY be OK for AGM. Its hopelessely wrong for GEL. But claims it is "automatic" which just means its 3 stage, not that it can tell what sort of battery it is charging...

Battery Maximizer
Lead-Acid Battery Charger
Instruction Manual
EA1065-P
24 Volt
VRLA / SLA / AGM / Gel
Fully Automatic

INTRODUCTION
The Battery Maximizer EA1065-P 24 volt battery charger is a fully automatic, multi-
stage full switching charger. It is designed to properly charge VRLA / SLA / AGM /
Gel lead-acid batteries without having to worry about overcharging. It may be used
in all parts of the world with its advanced universal AC input (110 or 220VAC). The
dual LEDs let you know the condition of the battery and if there are problems.

>>> Burgerman added, THIS IS IMPOSSIBLE UNLESS IT IS HAS A WAY TO SWITCH TO DIFFERENT CHARGE PROFILES.
And it doesent. So yes it can chare gel. As long as you dont mind throwing them away at around 40% of their normal lifespan.




SPECIFICATIONS
Input 100–240 VAC, 50/60Hz
Output 24 Volt DC Battery Charger
Dimensions: Height 1.60 in. Width 2.70 in. Length 6.06 in.
Weight 0.93 lbs.
Safety Listings
UL, CUL, CE
FCC Class B

CHARACTERISTICS
Universal AC input 100–240V, 50-60Hz
Charge condition:
Fast charge 29.4VDC A bit high, borderline OK on GOOD AGMs. WAY too high for gel.
Absorption 29.4VDC A bit high, borderline OK on GOOD AGMs. WAY too high for gel. Problem is it will also end too early. It doesent say. SHOULD go for around 8 hours CV before float. It wont.
Float charge 27.6VDC Should be 27V Gel, or at most 27.2V AGM longer term
Reverse polarity protection
Overvoltage protection
Short circuit protection
Lightweight
small size

IMPORTANT SAFETY INSTRUCTIONS
Rev. F
CAUTION: For use with LEAD-ACID batteries only VRLA, SLA, AGM, Gel (SEALED LEAD ACID /SLA, AND VALVE REGULATED LEAD ACID /VRLA ARE EITHER AGM OR GEL... THEY ARE JUST TRYING TO CATCH ALL, MORE SALES. UNSUTABLE FOR GEL. EVEN THOUGH THEY SHIP THESE WITH GEL BATTERY POWERCHAIRS.)
For indoor use only.
WARNING: To reduce risk of fire and electric shock,
install in a temperature and humidity controlled indoor
area, free from dust and conductive contaminants.
Disconnect from AC power before cleaning. Make sure
batteries are clean and properly connected. Keep away
from heat, fire and water.
There are no user serviceable parts on this charger.
If there is a problem or the cords have been damaged,
it must be serviced by qualified service personnel.
This device complies with Part 15 of the FCC rules.
Operation is subject to the following 2 conditions: (I) This
device may not cause harmful interference, and (2) this
device must accept any interference received, including
interference that may cause undesired operation.
WARRANTY
The warranty is for a period of 1 year from date of purchase
and covers manufacturer’s defects. The charger will be
replaced or repaired at the manufacturer’s discretion. Proof
of purchase is required.
Battery Maximizer
info@batterymaximizer.com

Dont be fooled. All the chargers, inc this CHINESE MADE ONE SUPPLIED BY PRIDE MOBILITY are not suitable for GEL and not great for AGM either. Voltages are wrong and we know they give a green light long before the battery is full and drop down to a lower float voltage. Which means a 15 to 20 hour wait before a full charge is achieved. And that tiny extra bit is the part that prevents deterioration through sulfation. So they overvolt and undercharge...

Correct charge voltages for MKs, AGM and GEL here which changes with temperature. Look at 20C for average room temperature:

[Burgerman]

Or...