we got two batteries same brand same voltage the only difference is one is rate 10 hr the other one is 20hr can them be join on parallel thans very much sorry about my english
You can connect the two batteries in parallel to achieve more amperage at the same voltage, however having two different Amp hour ratings on the batteries may allow one to absorb the charge current at differing rates, ie one may actually rob the other due to the differing capacities of the batterys.
It is always more prudent to use two identical type, amp hour rating and age of batteries together for long life and reliable performance.
In your case coupling the two batterys will limit the life of at least one of the battery's.