I have a 36 volt electric lift and if it sits a week or so the voltage drops to around 34V, after a good charge the voltage reads 37V or so but with a volt meter attached that reads to 1/100ths of a volt, the voltage continues to drop .01V every few seconds until it is back to 34V area. Is this a sign of the battery is near death or is there a possible way to get a bit more life out of it?