The real problem is that if you pull half an amp from those dry batteries the voltage falls from 1.55 to about .7 of a volt. They have a high resistance. They are hopeless at higher amps.
If you were to substitute those for a set of eneloops, which have much lower resistance, your voltage will not collapse, the chair will work more reliably and faster, and some are good in standby for many years. So recharge every 6 months.
I really suspect the tiny wires used for the OEM 9V transistor batteries are throttling any power I apply.
Yes, AA cells are limited but they must have many times the power of the OEM batteries.
If the power fails during the night... how much draw is there while the controls are powered up but no motor draw? I didn't act on it but a possible solution was suggested, to switch off the back up power when not needed for hours at a time. The first use was slow but adequate. After that not.
There are AC > DC > AC > DC ineffiencies in a UPS but... when I'm on generator, it can recharge for another night of use...
I'd like to know if others who posted UP SIZED their UPC... & how much... which are really intended just to protect a light load like a computer for a short period.
I'm convinced that there needs to be an on/off switch on the back up packs.
Might the transformer be backfeeding the house?
A friend has a propane powered backup generator... it cost a heck of a lot more than the imported diesel gen set. No, my generator is only a 6500 Honda, manual elect start.
The Westinghouse Ni-Mh 2000mAh are suggested to charge with the Eveloop charger. I think they are a simple knockoff.
The cells I ran the test with... have higher voltage (1.36V)... than the never charged ones (1.29v). I couldn't test the volts under load without rewiring & I was anxious get started.
I didn't check new charged cell voltage before I tested. I expected outcome of less than the 1.29V of an unused cell. I'll charge some others to get a fresh charged voltage. I don't think I can blame the cells.
It was slow... the lift is never fast... but it did Rescue me.
WIKIPEDIA
Self-discharge
NiMH cells had a somewhat higher self-discharge rate. The self-discharge is 5–20% on the first day and stabilizes around 0.5–4% per day at room temperature.
Low self-discharge
The low self-discharge nickel metal hydride battery (LSD NiMH) has a significantly lower rate of self-discharge. The innovation was introduced in 2005 by Sanyo, under their Eneloop brand. By using an improved electrode separator and improved positive electrode, manufacturers claim the cells retain 70–85% of their capacity when stored one year at 20 °C (68 °F). They are otherwise similar to other NiMH batteries and can be charged in typical NiMH chargers. These cells are marketed as "hybrid", "ready-to-use" or "pre-charged" rechargeables.
Separators keep the two electrodes apart to slow electrical discharge while allowing the transport of ionic charge carriers that close the circuit during the passage of current. High-quality separators are critical for battery performance.
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