Batteries loosing charge

[geordie graham]

I recently fitted two new 55ah batteries toa Jazzy 1121 and have never been happy with the how long you can go on one charge. The terrain is a bit hilly but no more than 30 mins downhill and half way back I get both red lights flashing. I decided to charge them fully wath a 7amp charger for 24 hours and then disconnected the charger. I have just connected the charger which tells me that the batteries are down to 75% after no use whatsoever. I have a tester but not a lot of knowledge of electronics,is there any simple tests I can do to find the problem. I have noticed thet the joystick housing is getting warm.
Thanks Graham

[Burgerman]

First, only MK gel, or Odyssey AGM batteries are worth bothering with. If you bought something cheaper online, best of luck, as you will need it...

2nd a mobility charger never charges batteries properly. And it certainly cant tell you the battery is at 75% state of charge. And these shorten service life.

So when you got the new batteries, (What make were these?) did you measure open circuit voltage? And what was it? If below say 12.5 or 6 volts, they should be returned as they will already be suffering some sulfation.

Then, did you connect both together as one in parallel at least 24 hours before fitting? If not, and one is a couple of tenths of a volt above the other, the first few charges will overcharge one, and undercharge the other causing damage to both.

Then did your charger charge them to the correct CV voltage, for long enough, before first use? (That would be 28.20v for gel, and 28.80 for AGM, followed by at least 6 hours at a lower 27.2 volts).

If you did anything different to the above then they are not charged correctly, and or wont last.

What is the voltage of each battery AFTER charge ends, and after sitting unused for 1 day?

[geordie graham]

Unfortunately I couldn’t find gel batteries,in the size that fits my chair. The charger I am using is not the original Numax DC24V/7A ,don’t know if that makes any difference.Thinking back the batteries were purchased at the same time as we were preparing to move and sat in the boxes they arrived in for maybe a couple of months which I am thinking could not of helped. I will check the voltage after each charge ends and sitting for one day unused and see what results I get.
Thanks for the quick reply
Graham

[Burgerman]

https://www.amazon.com/MK-Battery-M22NF ... B000NGPOU2 Available easily in US and UK at least.

It uses common 22nf sized batteries, and thats way too small regardless. The only ones that will likely work properly, are the commonly availabe MK gel above. In that size you wont get much range regardless. Other batteries will perform worse. And wont last as long.

[geordie graham]

I charged batteries for 16 hours and checked batteries which were 13.07 and 13.21 respectively. I then attached a multi meter to the xlr plug and set off around the street. The initial reading was 26.0 and after the small jaunt around the slightly hilly but still only 15 minute journey the reading was 22.4 and the battery meter was down to the 2 red lights. I then checked the batteries individually again and they read, the 13.2 had dropped to 12.99 and the 13.07 had dropped to10.8 !. Looks like at least one is shot but will change both. Is there any reason why one should go bad without the other even after not a great deal of use. Also how warm should the joystick housing get under the joystick. I’m now off onto tinternet looking for 22NF gel batteries in Spain.
Thanks again
Graham

[geordie graham]

PS I checked the batteries after an hour or so and the numbers had come back up,the 10.8 was 12.8 and the12.9 was 13.0
Graham

[Burgerman]

Your batteries are junk/ruined.

Buy MK Gel, or Odyssey.

When they arrive reject them if they are more than 0.1V different, or if either is below 12.6V.
Then connect both tegether in PARALLEL and leave them this way for 24 hours or longer.
Then fit them. And use a SUITABLE 3 stage charger, at 28.2V for MK gel, 29.4V for Odyssey.

Then after 6 to 10 normal use cycles, you will get full range. Charge often as possible and overnight if used at all. And at least 16 hours once a week.

[Fedor]

I want to warn about the MK, according to my data and the feedback of other people, the quality of their batteries has decreased or unstable. Perhaps they are still good, but not the same as before, while the price is the same. You should try the MK, but tell the seller about a possible moneyback. Good luck!

[martin007]

I’m now off onto tinternet looking for 22NF gel batteries in Spain.

> http://www.stsmedical.com/baterias-carg ... results=48

> https://www.ortopediasilvio.com/es/bate ... sld-g.html

> https://www.ortoweb.com/baterias-gel-50 ... gJq9vD_BwE

Choose yourself.

[martin007]

I want to warn about the MK, according to my data and the feedback of other people, the quality of their batteries has decreased or unstable. Perhaps they are still good, but not the same as before, while the price is the same. You should try the MK, but tell the seller about a possible moneyback. Good luck!

I have an acquaintance who thinks the same way you do.
"The quality of all battery manufacturers is lower than it was years ago."


What can we do?

[Burgerman]

No its not. WE and chairs have got heavier. Esp chairs.

I have tested recent MK batteries, and they are absolutely as good as ever. Measured accurately and graphed the data at the 24 hour rate, to fractions of an Ah down to 10.8V. When new, and when a year old. Theres barely any difference IF CHARGED PROPERLY!!!

[steves1977uk]

Go Lithium! (LiFePO4) Cheaper long term too...

Steve

[geordie graham]

Thanks everyone for the help and thanks martin007 for the links.

Gaham

[Fedor]

I admit that the opinion about quality is subjective, if the measured data does not confirm this.

Honestly, I think for the future of our industry it will be useful if all lead batteries turn into shit as quickly as possible. This will increase the interest of users to look for the best solution. And it will force the industry to introduce lithium.

[Burgerman]

15 years after every other battery powered device - esp electric vehicles - already did so.

Dont see many lead powered phones, laptops, bikes, cars, garden or building tools. My plasterer even has a small lithium CEMENT MIXER in my living room. Says building sites have no power! Says he can use it in the room he is working in.

My strimmer, and my auto mower, and all my hobby stuff, food mixer, cameras, drill all use lithium. Because its cheaper long term, better, lighter, faster charging, reliable.

But mobility? Lead!

[Burgerman]

Honestly, I think for the future of our industry it will be useful if all lead batteries turn into shit as quickly as possible. This will increase the interest of users to look for the best solution. And it will force the industry to introduce lithium.

Quite apart from the crap recharge time (16 hours for a FULL charge), the shrinking Ah as you take power faster, the 4 to 6 times lower energy density to begin with, the massive weight of lead, and the very limited cycle life of 3 to 5 hundred only, means they were ALWAYS crap!

These graphics are decieving. Because typically we start out with much more Ah with lithium in the same space. So the difference is even greater. In place of 70 lead, we fit 90, or 120, or 160Ah if doing the job properly because it fits!

USABLE Ah over a 24 hour period.

WORSE! LEAD'S ACTUAL available power! Remember that at 8mph you eat the battery in 2 hours, 16 miles. Look at the 2 hour image. THATS what you really get. It shrinks as you drive.

This is why you percieve the battery getting worse. Add a few kg, with 90kg worth of fancy power seating, or eat a few burgers, and the losses to the battery are huge. And it dies faster because you do this to it daily.

And LITHIUM stays the same Ah regardless of discharge rate. It does not shrink as you drive!!! And we started off with more Ah anyway:

Those of us using lithium understand this, not technically, but because it just keeps on rolling and the volts stay the same mile after mile!!!