Quick review LEOCH mobility batteris.

[Burgerman]

https://www.ebay.co.uk/itm/152632396375

I put a set of these on my tatty backup chair. I used them for 7 days and 7 (proper) charges.

First a quick explanation. Lead batteries are a balance/compromise of 4 things.
1.Cost (super pure materials, quality thin plate manufacturing etc) - the only way to improve all 3 of the following.

2.Capacity (Ah)
3.Internal resistance
4.Cycle Life

If any one of the 2, 3 or 4 is improved, then the others are reduced. So its a balance. Lets say you improved cycle life, then the capacity or internal resistance must get worse. Or both. Lets say you want to improve internal resistance, then cycle life or capacity is the casualty. Unless 1. is added...

So how are these Leoch deep cycle batteries?
They have a 350 to 400 cycle life. (less good than say Odyssey (400 to 450) or MK at 500 to 550)
They have good capacity at 85Ah at the 20h rate. Thats better than MK. And Odyssey.
But they have little "power". Or rather torque due to high internal resistace. So as I "gun" my chair (that is programmed to respond with urgency) all that happens is that the battery guage light dims and the voltage drops... And the thing has lost its power to wheelie. Or curb climb. Or to turn "NOW" when I say so. Its a bit like the joystick is connected by rubber bands.

So these batteries would be OK in a light chair, light user that has the typical delayed action stock type programming. And would offer good range and average cycle life. But if you plan on a chair that responds NOW, and that has been programmed to do so then avoid. Impedance is too high. Its all a compromise. They were cheap though...

The problem is that this 3 way balance which is the inherent problem with all deep cycle batteries, is pretty much the same across every battery you look at. Unless you spend a lot of money. These leoch batteries will be fine for less demanding users. Some though have even higher internal resistance. So be careful what you buy. If you ignore the battery label, and look at the casing. These are pretty much the same battery as offered by many vendors under different brand names. Cheap chinese made probably.

They charge easily, and reach the 1000thC termination point in approx 7.5 to 8 hours (while new). I am charging them in parallel at 14.5V and 40A and the shirley ZXD power supply is set to 3 stage, to terminate and go to float at 0.2A and float is set to 13.5V. One good thing about them is that they do charge faster than most. After the 8 hours at CV they are done. No long tailing off of current. Float isnt really needed. They are a good overnight charge choice if you only have 8 hours to spare. At least while they are new!
If charged properly they should stay this way. Personally I would rather they had made them lower impedance and 70Ah. A better compromise.

[greybeard]

Thanks BM. Useful.

[hobie1dog]

Great to have someone on here that is a true expert in batteries. Thanks

[Gnomatic]

I have a pair of Leoch 70Ah Gel in a chair, they've gotten little use in the two years since I got them and I try to stick them on a shirley charger every couple weeks.(though that sometimes stretches to a month or so)

This weekend I charged them overnight at 28.0v. The charger went into CV after 5min and ran 10-12hrs. When I unplugged the current had only fallen to ~0.35v and was holding steady, not really falling any more. So that doesn't seem so good.

[Gnomatic]

These are the LEOCH batteries I'm working with.

http://www.leoch.com/pdf/reserve-power/ ... 202102.pdf

[Burgerman]

The current may take days to drop. If they have been stored a long while. It will be a little sulfated. Some of that will, with a long slow soak on float return to the acid. Some will not. But you cant hold them at 14V for days. Those are better for cycle life being gel. But maybe even worse for internal resistance and lower capacity. Dont have a spec sheet. Gel may not drop as low in current as agm ever though, as they are harder to fully charge unless a long slow float charge is used. And are more sensitive to overcharge. You should limit the 14V CV to 12 to 14 hours max then drop to 13.5V float for a few days or even weeks (safely). The lower the voltage the less the gassing. The less the gassing the less wasted recombinant energy so current falls lower too. But the longer it takes to fully saturate the battery.