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Discussion Starter #1
hello!

First post and new to the world of EV’s so be gentle but here to ask a question hoping someone knows something.

I bought an Aixam Mega Van (2010 reg), for a business plan.

Having been told you need to keep it running as the batteries can degrade, I’ve realised we’re only getting about 20 miles per charge.

It should get around 30 and I’ve noticed that when the battery is full (and I reset the milage) we’re fine and dandy. However, after it gets down to about halfway it will promptly drop the last 3 bars instantly and alert me it needs a charge!

I know the batteries were replaced last year and suspect the last owners didn’t drive it as much as needed.

Anyone got any ideas as to how I save these batteries before we shell out £1,000+ to replace them?!
 

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It depends on what the batteries are that have been put in. Most problems are caused by people using leisure batteries not traction batteries. Do you have the 8 or 12 battery verions?
The 8 version has a lot less range and puts a lot more load / strain on the batteries.
As set of correct batteries will cost a good deal more than £1k, and last maybe 18 months of use. Do yours need watering or are they a sealed version?
Perhaps post some images of the separate batteries.
I have someone interested in putting some good used Lifepo4 into his and I have a pack of 16 210ah Calb cells for him, but if the sale doesnt go through, they will be for sale again. Lifepo4 (depending on the ah) will give you greater range, longer life and a significant reduction in weight, around 100kg compared to the 12 battery version. But you may need to change the charger (The chap who is interested has already had his changed as it failed some while ago and the newer on can be used with Lifepo4).
 

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Discussion Starter #5
Perhaps post some images of the separate batteries.
Good shout. I’ll do this asap.

As far as watered v sealed....being new to EV’s...to me this sounds like you’re asking me about Tartan Paint.

Batterys! Water!? Is this a trick?

20 mile range will be fine for the time being (although not ideal) as we’ll be locally based at first. However, depending on cost once we have the business up and running, we’ve shelled out quite a lot to get this going, Lifepo4 could be interesting and worth researching.

Thanks.

Pics soon.
 

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Discussion Starter #7
Here yarr....

12 of these in there but this is the best angle I could get without taking them out. Maybe this sheds some light:

8B2A5D41-7E57-415F-BF63-962531A99CD6.jpeg


Cheers all.
 

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Discussion Starter #9
They are original fitment gell cells, so no watering. Have you got 8 or 12 of them?
12.

If there’s a quick fix to get accurate charge reading or even restore some range...I would be over the moon.

Someone suggested I try and run the van down to now power...literally push it to the nearest plug once it dies and then give it a full charge. Something about resetting the brain of the van??!?! Problem is...I have no idea how long the van could run on limp mode!

If this is just because the batteries haven’t been looked after...and need replacing. Looks expensive! Especially considering you mentioned they could last 18 months. Any ifea what sort of cost would Lifepo 4 set us back on a project like this?

Many thanks for your replies!
 

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Its pointless running it down as far as you can, you run the risk of doing greater damage to the lowest batteries.
You need to charge the whole pack, then take individual battery voltages. for each one in each of the three rows, then use it and get it to shut down, then do the voltage checks again. The calculation of range is based on the current and the voltage if its re setting to 100% then thats doing its job. The cut out/ back is based upon low voltage . ie duff cells. But you have to do the cell voltages first. It may be that a re arrangement of the batteries could give you a more usable 8 block set, it just depends where the porr ones are .
The negative end of the pack is under the passenger seat,so number the voltages 1 to 4 along the passenger side , 5 to 8 down the middle and 9 to 12 along the drivers side with 12 at the back. Do the charge / dead voltages and post them on here.
A lifepo4 conversion depending on what charger you have would be in the region of £2.5 to 3k. But with a lot longer life than around 18 months for a set of lead. Occasionally I have used cells but the saving isnt huge over the new ones, ie £2 to 2.5k.
 

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Discussion Starter #11 (Edited)
Its pointless running it down as far as you can, you run the risk of doing greater damage to the lowest batteries.
You need to charge the whole pack, then take individual battery voltages. for each one in each of the three rows, then use it and get it to shut down, then do the voltage checks again. The calculation of range is based on the current and the voltage if its re setting to 100% then thats doing its job. The cut out/ back is based upon low voltage . ie duff cells. But you have to do the cell voltages first. It may be that a re arrangement of the batteries could give you a more usable 8 block set, it just depends where the porr ones are .
The negative end of the pack is under the passenger seat,so number the voltages 1 to 4 along the passenger side , 5 to 8 down the middle and 9 to 12 along the drivers side with 12 at the back. Do the charge / dead voltages and post them on here.
A lifepo4 conversion depending on what charger you have would be in the region of £2.5 to 3k. But with a lot longer life than around 18 months for a set of lead. Occasionally I have used cells but the saving isnt huge over the new ones, ie £2 to 2.5k.
Okay, this sounds like it makes sense to me...will rope in an electrician friend to assist.
Just to check, removing the batteries and testing one by one won't reset any software etc. I can remove them entirely, test and replace (charged up from the external charger) and not run the risk of them not playing ball anymore?!

Also...you do want me to run it down until it shuts down as previously suggested but...for reasons of testing...not to expect it to fix itself.

Anyone know how long Limp mode will run for on average? It could be a long time at 10 mph to get it to shut down completely.

Thanks.
 

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Done take them out.

Charge the van as normal.
Then by lifting the front seats and taking up the rear floor you can get to all the batteries.
Take each voltage. Drive it until it starts to cut back. Then re check.
This wont repair or sort anything. You have duff batteries we just need to work out what and where, incase you can get a better result with the batteries you have by moving them about and taking 4 out.. If they are so poor as need full replacement then we will know that for sure.
 

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660F3ECB-BD28-4272-BFEF-64DA41A3F4E9.jpeg
You should be able to condition each battery with a charger

This is what I’m doing to the nimh batteries in the estima

Went from 71 - 77 - 86% capacity over the 3 8hr cycles

JJ
 

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You need a battery conditioner

And you probably need one that discharges

You could try one of the standard battery conditioners but they normally rescue heavily discharged batteries

There is an AA one on amazon for £22

JJ
 

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Just do the voltage tests, dont faff around. Find out whats actually going on. You can spend days reconditioning and then its going to be just as bad. Once these have started to fail, all the reconditioners in the world wont halt the degeneration. They are nothing like Nimh that suffer from dentrites in the cell and high frequency charging can break those for a while, But these are good old Lead and they fail. Neither are they 1.5 v 2ah AA bateries but 12v 80+ah batteries .
 

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Discussion Starter #17 (Edited)
Done take them out.

Charge the van as normal.
Then by lifting the front seats and taking up the rear floor you can get to all the batteries.
Take each voltage. Drive it until it starts to cut back. Then re check.
This wont repair or sort anything. You have duff batteries we just need to work out what and where, incase you can get a better result with the batteries you have by moving them about and taking 4 out.. If they are so poor as need full replacement then we will know that for sure.
So, they all read 13v DC when fully charged.

But my electrician friend is thinking potentially that they would say that because theu are all connected. Do we need to disconnect them from each other, even temporarily to get individual readings?

Cheers Grumpy-B you’re a hero already in my eyes!

Empty readings to follow asap.
 

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Each parallel string may well read the same, but I would notn expect each of those 4 strings to be exactly the same voltage. 13v after charge is a bit low. If you can disconnect one lead from each battery then it would be much better to get the true individual voltages. And the same when you test after use.
 

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What 13v is suggesting that there is probably one poor battery in each of the parallel strings.
You have 4 batteries in a serial string, ie one voltage adding to the last to get you to the nominal 48v, then each of those serial batteries has 3 in a parallel string, ie in that layer of the serial string the batteries are connected + to + - to - so creating a larger capacity than a single battery. As you have found in a parallel string the voltages will tend to self level, the highest being taken down by the lowest.
If all of the serial strings are the same (13v ) then either all the separate batteries are working in a similar way or that each of the serial strings has the same number of faulty cells in each parallel string. Hopefully the latter is the case. As just taking out the really poor battery may mean the over all cabability isnt being taken down by those poor batteries.
The poor batteries will probably get to a high voltage during charge earlier than the rest, as well as go lov voltage under load. But you do have an ageing set of batteries, and any inprovement will only be a sto gap until they are all replaced. Its not worth replacing anything other than the full pack.
 

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Discussion Starter #20
Just do the voltage tests, dont faff around. Find out whats actually going on. You can spend days reconditioning and then its going to be just as bad. Once these have started to fail, all the reconditioners in the world wont halt the degeneration. They are nothing like Nimh that suffer from dentrites in the cell and high frequency charging can break those for a while, But these are good old Lead and they fail. Neither are they 1.5 v 2ah AA bateries but 12v 80+ah batteries .
So...just before limp mode kicked in...as I was dropping it off with my biz partner. No bars charge. Begging for a charge...retested batteries. All say 12v DC. :eek: I’m away for four days from tomorrow but interested to see what you suggest?

Sam.
 
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