Your mobility charger sucks

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Your mobility charger sucks

Postby Burgerman » 11 Jan 2018, 12:18

Heres why:

When you charge a battery you present it with a set maximum level of amps, and a fixed voltage.

For this battery that was 16 Amps, (double the power of a mobility charger) and the exact correct voltage. That was 14.7Volts (29.4Volts). This is recommended for Odyssey batteries.

The essensial thing when charging any lead DEEP CYCLE battery is to make sure that the battery is 100% + recharged, and then some! Every cycle. Failure to do this, means some of the lead sulfates remain on the battery plates every cycle. It coates the plates as it discharges. Charging returns the sulfates back to the electrolyte. This sulfate layer builds up over time if you dont 100% charge, and means your battery suffers shorter range, dies a rapid death.

As you charge the voltage rises at max amps, until the preset voltage (14.70V per battery here) is reached. The charger holds it at this voltage, and the battery then absorbs the power over a long time. As it does so current or Amps, gradually drops away to an extremely low level. Only when it has been at this constant voltage for 8 hours, or until this current falls to a tiny 70mA or lower, on a 70Ah battery is it fully charged.

Heres an example. I just charged a heavily discharged battery to show how long this process really takes. Notice that this was charged at 16 Amps, and so DOUBLE the power of your mobility charger. It yet still took some THIRTEEN hours. Any less than this, and the battery CANNOT be fully charged.

If your mobility charger is doing it faster than the perfect settings here, then it is lying to you, and it is leaving the battery less than 100% charged and so it will gradually sulfate and die. There is no way to do this faster! If your green light is on, at 8AM, your charger is crap!

Remember your weedy 8A mobility charger will be a lot SLOWER than the graph below.
And remember that Gel batteries are generally about 25% slower to charge too!
So 16 to 20 hours would likely be a full charge using a mobility charger if it stayed on long enough!
Attachments
Test 1 Amps.jpg
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Re: Your mobility charger sucks

Postby elryko1992 » 11 Jan 2018, 13:20

So what charger is good to buy for my MK Battery?

CTEK XT 14000 is good?

https://www.ctek.com/products/on-board/xt-14000
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Re: Your mobility charger sucks

Postby steves1977uk » 11 Jan 2018, 14:42

That CTEK charger still charges at a higher voltage (28.8v), whereas the optimal voltage is 28.2v and a 1000th C termination current for MK Gels. Just don't expect the best cycle life when using chargers like these.

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Re: Your mobility charger sucks

Postby elryko1992 » 11 Jan 2018, 15:31

But what charger tell me some model.
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Re: Your mobility charger sucks

Postby Burgerman » 11 Jan 2018, 15:41

I have a 7A ctek charger. They stop charging at about 1A... OK for long term storage. Then give a brief burst every 10 mins. OK for charging a car but not great for deep cycle use. And useless for gel.

From Ctek 14000 manual:
14.4V until after the current dropped to 4.5A, max 12h.


So it stops charge at 4.5A and thats not good!

The charger I am using is the PL8v2 of course. Other chargers? They never give enough detail. So unless you measure it who knows. And they cannot charge more than 10 to 12A via the official charge port. So 16 hours to full... There are a few marine chargers that have gel specific settings that work for MK well.
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Re: Your mobility charger sucks

Postby steves1977uk » 11 Jan 2018, 17:57

https://www.portablepowertech.com/produ ... y-charger/ This is the closest charger that will charge MK Gels at 28.2v 15a. So you would need an Anderson connection wired directly to the batteries as the XLR plug/port and/or joystick cable would melt! Or go the PL8 route...

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Re: Your mobility charger sucks

Postby Burgerman » 11 Jan 2018, 18:17

That looks OK on mode 4 for gels, connected via Anderson. Provided it maintains CV stage right down to around 70mA, and or 8 to 12 hours time limit. But it only says:

Absorption (CV)
28.2V,
1A~0A

What does that mean? If it stops at 1A (or even 500mA) thats way too soon. If it stops after 4 hours thats too soon, after 12 is too late. But we cant know! As usual its guesswork. https://www.portablepowertech.com/libra ... asheet.pdf
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Re: Your mobility charger sucks

Postby elryko1992 » 11 Jan 2018, 19:06

So its not to good this charger from Steve? i really want to buy a good charger.

i have this charger from Invacare 24v 8A: https://www.ebay.co.uk/itm/Electric-Whe ... 2973951012
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Re: Your mobility charger sucks

Postby elryko1992 » 11 Jan 2018, 19:41

what you say about the Noco 1500? : https://no.co/g15000
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Re: Your mobility charger sucks

Postby steves1977uk » 11 Jan 2018, 20:36

That's even worst! It says 29v for Gel and 29.6v for AGM :o What a way to shorten cycle life! czy

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Re: Your mobility charger sucks

Postby rover220 » 11 Jan 2018, 20:47

Ring rscpr chargers are all you need.
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Re: Your mobility charger sucks

Postby Burgerman » 11 Jan 2018, 21:01

Not avail in US. And hard to find in UK. Also, it is still 8A.

Is that an issue? Yes. Because it means the CC part takes or can take up to 8 hours on a discharged group 24 before you even get to the 8 hours plus of CV. So you will be 16 hours to a full charge even if partially discharged. It may say its done sooner, but its not.

https://www.ebay.co.uk/p/Ring-Automotiv ... 1037972986 Will work on gel, as long as you leave it connected and on float as often as possible for as long as possible.
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Re: Your mobility charger sucks

Postby elryko1992 » 11 Jan 2018, 21:02

rover220 wrote:Ring rscpr chargers are all you need.


this is good: https://www.amazon.co.uk/Ring-Automotiv ... B009CRGNVC
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Re: Your mobility charger sucks

Postby Burgerman » 11 Jan 2018, 21:03

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Re: Your mobility charger sucks

Postby elryko1992 » 11 Jan 2018, 21:09

Burgerman wrote:No 24V here will work. https://www.ebay.co.uk/p/Ring-Automotiv ... 1037972986


ok thanks BM. So this is good to buy for MK Battery?
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Re: Your mobility charger sucks

Postby Burgerman » 11 Jan 2018, 21:19

How to PROPERLY test a battery.
If your tech guy does less than this he is wasting your time.

Here is the discharge test to MEASURE CAPACITY for the Odyssey in my 8 YEAR OLD chair. This was built and finished in 2009, a BM1. It was stored at 13.35V on cont float for 7 years under a dust sheet in my kitchen, and was used for 3 months recently. So also 90 cycles.

Manufacturer table, showing expected capacity discharged down to 10.5V at a specific discharge rate. I chose 10 hour rate, (at 6.5Amps) discharge. Instead of 6.3A. So it ended before I needed turning!
This is for 25C. My room is 17C. So we correct that (another chart!) by deducting 1.8Ah from the figure quoted.
Without such a chart/spec from the manufacturer its IMPOSSIBLE to test any battery.

10.5v.jpg


So I would expect to get 63Ah out. At 10.5V termination @ 6.3A discharge although I used 6.5A. Deduct 1.8Ah for temp and I would expect to see 61.2Ah out of the battery if it was brand new.

discharge.jpg


We actually got 60Ah. So this battery has lost just 1.2Ah compared to new. Thats the advantage of correct storage and correct charging methods. It also shows how useful the PL8 is, and how crappy the dealers tests are.
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Re: Your mobility charger sucks

Postby elryko1992 » 11 Jan 2018, 21:24

interesting think, thanks, i will buy this charger. And i need to make a anderson connection directly to battery no?
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Re: Your mobility charger sucks

Postby Burgerman » 11 Jan 2018, 21:28

ok thanks BM. So this is good to buy for MK Battery?


As long as you leave connected 24 hours say once a week. Set to 14.1 (28.2V 8A) It will be OK. Its only 8 amp so can charge via normal XLR type connector, but anderson and heavier cables will work better still.
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Re: Your mobility charger sucks

Postby elryko1992 » 11 Jan 2018, 21:32

ok, when i buy the charger i will set from LCD no?
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Re: Your mobility charger sucks

Postby Burgerman » 12 Jan 2018, 01:19

Buttons... 8 amps. Gel, so 28.2V.
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Re: Your mobility charger sucks

Postby elryko1992 » 13 Jan 2018, 12:48

Ok thanks. I buy the charger from Germany i found new 46€ + shipping, in Italy is 51€, I waiting to see how good is.
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Re: Your mobility charger sucks

Postby Dan » 16 Jan 2018, 14:21

Just found the instruction manual for a mobility charger that came with a Salsa M2.
Model 4C24080A. The specification say its output is 8A DC, charging voltage 28.8V, floating voltage 27.6V.

Charging method, constant current two stage constant voltage. But I have noticed that it will stop charging if you leave it plugged in long enough.

It says the battery is fully charged when the green light comes on (floating charge).

How come some of these charger say do not disconnect when the charging light is orange? Or only in an emergency?
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Re: Your mobility charger sucks

Postby Burgerman » 16 Jan 2018, 14:41

Because in stead of sensing current at CV so they know when to stop, they just use a timer. So you will overcharge if you plug it back in...

Its worse than that.
First, its charging at too high volts for gel. (Ok for AGM only).
Second, it gives you the green light, as soon as it cuts off the CV stage which it does far too soon in most cases. Needs 8 hours at CV. About 14 to 16 hours total. So the green light does NOT signify that its fully charged.
Third. Only after a further 6 to 12 hours AFTER the green, allowing the float to complete the charge is it actually fully charged. 27.6 is too high for long term float. So it turns off...
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